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Marzano-Miranda A, Pereira Cardoso-Oliveira G, Carla de Oliveira I, Carvalho Mourão L, Reis Cussat L, Gomes Fraga V, Delfin Chávez Olórtegui C, Jesus Fernandes Fontes C, Castanheira Bartholomeu D, Braga EM. Identification and serological responses to a novel Plasmodium vivax merozoite surface protein 1 ( PvMSP-1) derived synthetic peptide: a putative biomarker for malaria exposure. PeerJ 2024; 12:e17632. [PMID: 38948214 PMCID: PMC11212635 DOI: 10.7717/peerj.17632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 06/04/2024] [Indexed: 07/02/2024] Open
Abstract
Background The integration of diagnostic methods holds promise for advancing the surveillance of malaria transmission in both endemic and non-endemic regions. Serological assays emerge as valuable tools to identify and delimit malaria transmission, serving as a complementary method to rapid diagnostic tests (RDT) and thick smear microscopy. Here, we evaluate the potential of antibodies directed against peptides encompassing the entire amino acid sequence of the PvMSP-1 Sal-I strain as viable serological biomarkers for P. vivax exposure. Methods We screened peptides encompassing the complete amino acid sequence of the Plasmodium vivax Merozoite Surface Protein 1 (PvMSP-1) Sal-I strain as potential biomarkers for P. vivax exposure. Here, immunodominant peptides specifically recognized by antibodies from individuals infected with P. vivax were identified using the SPOT-synthesis technique followed by immunoblotting. Two 15-mer peptides were selected based on their higher and specific reactivity in immunoblotting assays. Subsequently, peptides p70 and p314 were synthesized in soluble form using SPPS (Solid Phase Peptide Synthesis) and tested by ELISA (IgG, and subclasses). Results This study unveils the presence of IgG antibodies against the peptide p314 in most P. vivax-infected individuals from the Brazilian Amazon region. In silico B-cell epitope prediction further supports the utilization of p314 as a potential biomarker for evaluating malaria transmission, strengthened by its amino acid sequence being part of a conserved block of PvMSP-1. Indeed, compared to patients infected with P. falciparum and uninfected individuals never exposed to malaria, P. vivax-infected patients have a notably higher recognition of p314 by IgG1 and IgG3.
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Affiliation(s)
- Aline Marzano-Miranda
- Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | - Luiza Carvalho Mourão
- Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Letícia Reis Cussat
- Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Vanessa Gomes Fraga
- Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | | | - Erika M. Braga
- Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
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Amaral PST, Garcia KKS, Suárez-Mutis MC, Coelho RR, Galardo AK, Murta F, Moresco GG, Siqueira AM, Gurgel-Gonçalves R. Malaria in areas under mining activity in the Amazon: A review. Rev Soc Bras Med Trop 2024; 57:e002002024. [PMID: 38922216 PMCID: PMC11210384 DOI: 10.1590/0037-8682-0551-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 05/09/2024] [Indexed: 06/27/2024] Open
Abstract
Deforestation and high human mobility due to mining activities have been key to the increase in malaria cases in the Americas. Here, we review the epidemiological and control aspects of malaria in the Amazon mining areas. Epidemiological evidence shows: 1) a positive correlation between illegal mining activity and malaria incidence, mostly in the Amazon region; 2) most Brazilian miners are males aged 15-29 years who move between states and even countries; 3) miners do not fear the disease and rely on medical care, diagnosis, and medication when they become ill; 4) illegal mining has emerged as the most reported anthropogenic activity within indigenous lands and is identified as a major cause of malaria outbreaks among indigenous people in the Amazon; and 5) because mining is largely illegal, most areas are not covered by any healthcare facilities or activities, leading to little assistance in the diagnosis and treatment of malaria. Our review identified five strategies for reducing the malaria incidence in areas with mining activities: 1) reviewing legislation to control deforestation and mining expansion, particularly in indigenous lands; 2) strengthening malaria surveillance by expanding the network of community health agents to support rapid diagnosis and treatment; 3) reinforcing vector control strategies, such as the use of insecticide-treated nets; 4) integrating deforestation alerts into the national malaria control program; and 5) implementing multi-sectoral activities and providing prompt assistance to indigenous populations. With this roadmap, we can expect a decrease in malaria incidence in the Amazonian mining areas in the future.
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Affiliation(s)
- Pablo Sebastian Tavares Amaral
- Universidade de Brasília, Faculdade de Medicina, Programa de Pós-graduação em Medicina Tropical, Brasília, DF, Brasil
- Secretaria de Vigilância em Saúde e Ambiente, Ministério da Saúde, Brasília, DF, Brasil
| | - Klauss Kleydmann Sabino Garcia
- Universidade de Brasília, Faculdade de Medicina, Programa de Pós-graduação em Medicina Tropical, Brasília, DF, Brasil
- Secretaria de Vigilância em Saúde e Ambiente, Ministério da Saúde, Brasília, DF, Brasil
- Universidade de Brasília, Faculdade de Ciências da Saúde, Brasília, DF, Brasil
| | | | - Ronan Rocha Coelho
- Secretaria de Vigilância em Saúde e Ambiente, Ministério da Saúde, Brasília, DF, Brasil
| | - Allan Kardec Galardo
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá, Macapá, AP, Brasil
| | - Felipe Murta
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Departamento de Ensino e Pesquisa, Manaus, AM, Brasil
| | - Gilberto Gilmar Moresco
- Secretaria de Vigilância em Saúde e Ambiente, Ministério da Saúde, Brasília, DF, Brasil
- Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-graduação em Saúde Coletiva, Brasília, DF, Brasil
| | - André Machado Siqueira
- Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil
| | - Rodrigo Gurgel-Gonçalves
- Universidade de Brasília, Faculdade de Medicina, Laboratório de Parasitologia Médica e Biologia Vetores, Brasília, DF, Brasil
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Sanna A, Suárez-Mutis M, Lambert Y, Carvalho L, Cairo H, Cox H, de Bort C, Gomes do Socorro Mendonça M, Forero-Peña DA, Gabaldón-Figueira JC, Grillet ME, Klein F, Lazarus C, Lazrek Y, Louzada J, Malafaia D, Marchesini P, Musset L, Oliveira-Ferreira J, Peterka C, Rousseau C, Roux E, Villegas L, Vreden S, Wiedner-Papin S, Laporta GZ, Hiwat H, Douine M. Cooperation for malaria control and elimination in the Guiana Shield. Lancet Glob Health 2024; 12:e875-e881. [PMID: 38614635 DOI: 10.1016/s2214-109x(24)00047-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/28/2023] [Accepted: 01/23/2024] [Indexed: 04/15/2024]
Abstract
The Guiana Shield, a small region of South America, is currently one of the main hotspots of malaria transmission on the continent. This Amazonian area is characterised by remarkable socioeconomic, cultural, health, and political heterogeneity and a high degree of regional and cross-border population mobility, which has contributed to the increase of malaria in the region in the past few years. In this context, regional cooperation to control malaria represents both a challenge and an indispensable initiative. This Viewpoint advocates for the creation of a regional cooperative mechanism for the elimination of malaria in the Guiana Shield. This strategy would help address operational and political obstacles to successful technical cooperation in the region and could contribute to reversing the regional upsurge in malaria incidence through creating a functional international control and elimination partnership.
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Affiliation(s)
- Alice Sanna
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France.
| | - Martha Suárez-Mutis
- Laboratory of Parasitic Diseases, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil; International Joint Laboratory Sentinela, Fundação Oswaldo Cruz, University of Brasília, French National Research Institute for Sustainable Development, Rio de Janeiro, Brazil
| | - Yann Lambert
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
| | | | - Hedley Cairo
- National Malaria Program, Ministry of Health, Paramaribo, Suriname
| | - Horace Cox
- Vector-Borne Diseases Unit, Caribbean Public Health Agency, Port of Spain, Trinidad and Tobago
| | - Clara de Bort
- Regional Health Agency, Cayenne, French Guiana, France
| | | | - David A Forero-Peña
- Faculty of Medicine, Central University of Venezuela, Caracas, Venezuela; Biomedical Research and Therapeutic Vaccines Institute, Ciudad Bolívar, Venezuela
| | | | - Maria Eugenia Grillet
- Laboratory of Biology of Vectors and Parasites, Institute of Zoology and Tropical Ecology, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela
| | - François Klein
- Directorate General for Health, Ministry of Health and Prevention, Paris, France
| | - Clément Lazarus
- Directorate General for Health, Ministry of Health and Prevention, Paris, France
| | - Yassamine Lazrek
- Laboratory of Parasitology, Pasteur Institute in French Guiana, Cayenne, French Guiana, France
| | - Jaime Louzada
- Department of Nursing Science, Federal University of Roraima, Boa Vista, Brazil
| | - Dorinaldo Malafaia
- Vigifronteiras Program, Fundação Oswald Cruz, Rio de Janeiro, Brazil; Chamber of Deputies, National Congress, Brasília, Brazil
| | - Paola Marchesini
- Overall Coordination of Surveillance of Zoonoses and Vector-Borne Diseases, Ministry of Health of Brazil, Brasília, Brazil
| | - Lise Musset
- Laboratory of Parasitology, Pasteur Institute in French Guiana, Cayenne, French Guiana, France
| | - Joseli Oliveira-Ferreira
- Laboratory of Immunoparasitology, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Cassio Peterka
- Coordination of Malaria Elimination, Ministry of Health of Brazil, Brasília, Brazil
| | - Cyril Rousseau
- Division of Decentralized Primary Care Centers, Cayenne Hospital, Cayenne, French Guiana, France
| | - Emmanuel Roux
- ESPACE-DEV, French National Research Institute for Sustainable Development, University of Montpellier, University of the French West Indies, University of French Guiana, University of Reunion Island, and University of Perpignan Via Domitia, Montpellier, France; International Joint Laboratory Sentinela, Fundação Oswaldo Cruz, University of Brasília, French National Research Institute for Sustainable Development, Rio de Janeiro, Brazil
| | | | - Stephen Vreden
- Foundation for the Advancement of Scientific Research in Suriname, Paramaribo, Suriname
| | | | | | - Helene Hiwat
- National Malaria Program, Ministry of Health, Paramaribo, Suriname
| | - Maylis Douine
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
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Allel K, Cabada MM, Lau C, Mills D, Franklin RC, Zhu Y, Furuya-Kanamori L. Causes of death among international travellers in Peru, 2017 to 2021. J Travel Med 2024; 31:taad163. [PMID: 38127642 PMCID: PMC10823482 DOI: 10.1093/jtm/taad163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/12/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND The wellbeing and safety of international tourists is a paramount concern for governments and stakeholders. Mortality among travellers and the causes of death serve as a significant metric of destination safety. We describe the epidemiology and causes of death among international travellers in Peru. METHODS Data retrieved from the Peruvian government's deaths certificates registry included all non-residents who died between January 2017 and December 2021. We analysed the national incidence and causes of death among international travellers in Peru. Causes of death were classified into non-communicable diseases (NCD), communicable diseases and injuries. We classified fatalities according to the existence of preventive measures that could be provided during the travel medicine consultation to decrease the risk. RESULTS We obtained records from 1514 deaths among international travellers (973 males, 64%). The incidence increased from 0.2 deaths per 10 000 travellers in 2017 to 9.9 in 2021. NCDs were the most common causes of death (n = 560, 37%), followed by communicable diseases (n = 487, 32%), and injuries (n = 321, 21%). Causes of death were unknown in 9.7% of the records. The leading causes of death in these categories were cancer, cardiovascular disease, COVID-19 and trauma. We found similar sex distribution of NCDs in travellers aged >50 years and higher rates of communicable diseases among males across all ages. Injury-associated deaths were significantly higher among males aged 18-29 years (P < 0.001) compared with other sex-age groups. We estimated that for 57.7% of deaths risk could have been decreased through pre-travel advice. CONCLUSION Rates of deaths among travellers to Peru increased over time. Most deaths were due to NCDs, followed by communicable diseases and injuries. Pre-travel medical optimization and effective advice focused on age-sex and destination specific risks could reduce risk among travellers. Increased awareness among travel medicine practitioners and improvement of emergency medical response systems in Peru could decrease mortality.
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Affiliation(s)
- Kasim Allel
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
- Institute for Global Health, University College London, London WC1E 6BT, UK
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane 4029, Australia
| | - Miguel M Cabada
- Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555, USA
- Cusco Branch – Alexander von Humboldt Tropical Medicine Institute, Universidad Peruana Cayetano Heredia, Cusco, Peru
| | - Collen Lau
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane 4029, Australia
| | - Deborah Mills
- Dr Deb The Travel Doctor, Travel Medicine Alliance, Brisbane 4000, Australia
| | - Richard C Franklin
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia
| | - Yan Zhu
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane 4029, Australia
- Zhuhai International Travel Healthcare Center of China Customs, Zhuhai 519020, China
| | - Luis Furuya-Kanamori
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane 4029, Australia
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Alcântara JA, de Araújo FSA, da Costa Paz A, Alencar RM, de Albuquerque Caldas BY, Godoy RSM, Lacerda MVG, de Melo GC, Monteiro WM, de Souza Sampaio V, Secundino NFC, Duarte APM, Santana RAG, Pimenta PFP. Effect of fluralaner on the biology, survival, and reproductive fitness of the neotropical malaria vector Anopheles aquasalis. Malar J 2023; 22:337. [PMID: 37936198 PMCID: PMC10631211 DOI: 10.1186/s12936-023-04767-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 10/24/2023] [Indexed: 11/09/2023] Open
Abstract
BACKGROUND Reducing mosquito abundance or interfering with its ability to support the parasite cycle can help to interrupt malaria in areas of significant risk of malaria transmission. Fluralaner is a safe and effective drug for veterinary use indicated for the treatment against fleas and ticks which acts as an antagonist of chloride ion channels mediated by γ-aminobutyric acid (GABA), preventing the entry of these ions into the postsynaptic neuron, leading to hyperexcitability of the postsynaptic neuron of the central nervous system of arthropods. Fluralaner demonstrated insecticidal activity against different insect species. METHODS The study aimed to evaluate the effects of fluralaner on the biology, survival, and reproductive fitness of Anopheles aquasalis. The following lethal concentrations (LC) were determined for An. aquasalis: LC5 = 0.511 µM; LC25 = 1.625 µM; LC50 = 3.237 µM. RESULTS A significant decrease (P < 0.001) was evident in the number of eggs, larvae, and pupae in the group exposed to a sublethal dose of fluralaner when compared to a control group (without the drug). Using blood from dogs after administration of fluralaner, it was observed that the drug causes 100% mortality in An. aquasalis in less than 24 h after feeding; this effect remains even after 90 days in all samples. DISCUSSION Fluralaner showed the same result for up to 60 days, and after that, there was a slight reduction in its effect, evidenced by a decrease in the percentage of dead females; however, still significant when compared to the control group. CONCLUSION Fluralaner affects the biology and reduction of survival in An. aquasalis in a lasting and prolonged period, and its fecundity with lower dosages, is a strong candidate for controlling disease vectors.
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Affiliation(s)
- João Arthur Alcântara
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
| | - Francys Sayara Andrade de Araújo
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
| | - Andréia da Costa Paz
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
| | - Rodrigo Maciel Alencar
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
| | | | - Raquel Soares Maia Godoy
- Programa de Pós-Graduação Em Ciências da Saúde, FIOCRUZ-Belo Horizonte, Belo Horizonte, Minas Gerais, Brazil
- Instituto René Rachou-Fundação Oswaldo Cruz-(IRR-Fiocruz Minas), Belo Horizonte, Brazil
| | - Marcus Vinicius Guimarães Lacerda
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
- Instituto Leônidas e Maria Deane - Fundação Oswaldo Cruz - (ILMD - Fiocruz Amazônia), Manaus, Brazil
- University of Texas Medical Branch (UTMB), Galveston, USA
| | - Gisely Cardoso de Melo
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
| | - Wuelton Marcelo Monteiro
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
| | - Vanderson de Souza Sampaio
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
| | - Nágila Francinete Costa Secundino
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
- Programa de Pós-Graduação Em Ciências da Saúde, FIOCRUZ-Belo Horizonte, Belo Horizonte, Minas Gerais, Brazil
- Instituto René Rachou-Fundação Oswaldo Cruz-(IRR-Fiocruz Minas), Belo Horizonte, Brazil
| | - Ana Paula Marques Duarte
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
- Instituto René Rachou-Fundação Oswaldo Cruz-(IRR-Fiocruz Minas), Belo Horizonte, Brazil
| | - Rosa Amélia Gonçalves Santana
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil
- Instituto Leônidas e Maria Deane - Fundação Oswaldo Cruz - (ILMD - Fiocruz Amazônia), Manaus, Brazil
| | - Paulo Filemon Paolucci Pimenta
- Programa de Pós-graduação em Medicina Tropical-Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (PPGM-UEA/FMT-HVD), Manaus, Brazil.
- Departamento de Ensino e Pesquisa-Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (DENPE/FMT-HVD), Manaus, Brazil.
- Programa de Pós-Graduação Em Ciências da Saúde, FIOCRUZ-Belo Horizonte, Belo Horizonte, Minas Gerais, Brazil.
- Instituto René Rachou-Fundação Oswaldo Cruz-(IRR-Fiocruz Minas), Belo Horizonte, Brazil.
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Corder RM, Arez AP, Ferreira MU. Individual variation in Plasmodium vivax malaria risk: Are repeatedly infected people just unlucky? PLoS Negl Trop Dis 2023; 17:e0011020. [PMID: 36634044 PMCID: PMC9836309 DOI: 10.1371/journal.pntd.0011020] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Extensive research has examined why some people have frequent Plasmodium falciparum malaria episodes in sub-Saharan Africa while others remain free of disease most of the time. In contrast, malaria risk heterogeneity remains little studied in regions where P. vivax is the dominant species. Are repeatedly infected people in vivax malaria settings such as the Amazon just unlucky? Here, we briefly review evidence that human genetic polymorphism and acquired immunity after repeated exposure to parasites can modulate the risk of P. vivax infection and disease in predictable ways. One-fifth of the hosts account for 80% or more of the community-wide vivax malaria burden and contribute disproportionally to onward transmission, representing a priority target of more intensive interventions to achieve malaria elimination. Importantly, high-risk individuals eventually develop clinical immunity, even in areas with very low or residual malaria transmission, and may constitute a large but silent parasite reservoir.
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Affiliation(s)
- Rodrigo M. Corder
- Department of Epidemiology and Biostatistics, University of California, Berkeley School of Public Health, Berkeley, California, United States of America
| | - Ana Paula Arez
- Global Health and Tropical Medicine (GHTM), institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Lisbon, Portugal
| | - Marcelo U. Ferreira
- Global Health and Tropical Medicine (GHTM), institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Lisbon, Portugal
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail: ,
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7
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Barros LB, Calil PR, Rodrigues PT, Tonini J, Fontoura PS, Sato PM, Cardoso MA, Russo MWDAA, Cavasini CE, Fernandes ARDJ, Ferreira MU. Clinically silent Plasmodium vivax infections in native Amazonians of northwestern Brazil: acquired immunity or low parasite virulence? Mem Inst Oswaldo Cruz 2022; 117:e220175. [PMID: 36542002 PMCID: PMC9756956 DOI: 10.1590/0074-02760220175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Malaria remains common among native Amazonians, challenging Brazil's elimination efforts. OBJECTIVES We examined the epidemiology of malaria in riverine populations of the country's main hotspot - the upper Juruá Valley in Acre state, close to the Brazil-Peru border, where Plasmodium vivax accounts for > 80% of cases. METHODS Participants (n = 262) from 10 villages along the Azul River were screened for malaria parasites by microscopy and genus-specific, cytochrome b (cytb) gene-based polymerase chain reaction. Positive samples were further tested with quantitative TaqMan assays targeting P. vivax- and P. falciparum-specific cytb domains. We used multiple logistic regression analysis to identify independent correlates of P. vivax infection. FINDINGS Microscopy detected only one P. vivax and two P. falciparum infections. TaqMan assays detected 33 P. vivax infections (prevalence, 11.1%), 78.1% of which asymptomatic, with a median parasitaemia of 34/mL. Increasing age, male sex and use of insecticide-treated bed nets were significant predictors of elevated P. vivax malaria risk. Children and adults were similarly likely to remain asymptomatic once infected. MAIN CONCLUSIONS Our findings are at odds with the hypothesis of age-related clinical immunity in native Amazonians. The low virulence of local parasites is suggested as an alternative explanation for subclinical infections in isolated populations.
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Affiliation(s)
- Luiza Barbosa Barros
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil
| | - Priscila Rodrigues Calil
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil
| | - Priscila Thihara Rodrigues
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil
| | - Juliana Tonini
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil
| | - Pablo Secato Fontoura
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil
| | - Priscila Moraes Sato
- Universidade de São Paulo, Faculdade de Saúde Pública, Departamento de Nutrição, São Paulo, SP, Brasil
| | - Marly Augusto Cardoso
- Universidade de São Paulo, Faculdade de Saúde Pública, Departamento de Nutrição, São Paulo, SP, Brasil
| | | | - Carlos Eduardo Cavasini
- Faculdade de Medicina de São José do Rio Preto, Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, São José do Rio Preto, SP, Brasil
| | | | - Marcelo Urbano Ferreira
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil,Universidade Nova de Lisboa, Instituto de Higiene e Medicina Tropical, Lisboa, Portugal,+ Corresponding author: /
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8
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Tashi T, Upadhye A, Kundu P, Wu C, Menant S, Soares RR, Ferreira MU, Longley RJ, Mueller I, Hoang QQ, Tham WH, Rayner JC, Scopel KKG, Lima-Junior JC, Tran TM. Longitudinal IgG antibody responses to Plasmodium vivax blood-stage antigens during and after acute vivax malaria in individuals living in the Brazilian Amazon. PLoS Negl Trop Dis 2022; 16:e0010773. [PMID: 36417454 PMCID: PMC9728838 DOI: 10.1371/journal.pntd.0010773] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 12/07/2022] [Accepted: 11/11/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND To make progress towards malaria elimination, a highly effective vaccine targeting Plasmodium vivax is urgently needed. Evaluating the kinetics of natural antibody responses to vaccine candidate antigens after acute vivax malaria can inform the design of serological markers of exposure and vaccines. METHODOLOGY/PRINCIPAL FINDINGS The responses of IgG antibodies to 9 P. vivax vaccine candidate antigens were evaluated in longitudinal serum samples from Brazilian individuals collected at the time of acute vivax malaria and 30, 60, and 180 days afterwards. Antigen-specific IgG correlations, seroprevalence, and half-lives were determined for each antigen using the longitudinal data. Antibody reactivities against Pv41 and PVX_081550 strongly correlated with each other at each of the four time points. The analysis identified robust responses in terms of magnitude and seroprevalence against Pv41 and PvGAMA at 30 and 60 days. Among the 8 P. vivax antigens demonstrating >50% seropositivity across all individuals, antibodies specific to PVX_081550 had the longest half-life (100 days; 95% CI, 83-130 days), followed by PvRBP2b (91 days; 95% CI, 76-110 days) and Pv12 (82 days; 95% CI, 64-110 days). CONCLUSION/SIGNIFICANCE This study provides an in-depth assessment of the kinetics of antibody responses to key vaccine candidate antigens in Brazilians with acute vivax malaria. Follow-up studies are needed to determine whether the longer-lived antibody responses induced by natural infection are effective in controlling blood-stage infection and mediating clinical protection.
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Affiliation(s)
- Tenzin Tashi
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Microbiology and Immunology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Aditi Upadhye
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Prasun Kundu
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Chunxiang Wu
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Sébastien Menant
- Infectious Diseases and Immune Defence Division, Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Roberta Reis Soares
- Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, Nova University of Lisbon, Lisbon, Portugal
| | - Rhea J. Longley
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Ivo Mueller
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Quyen Q. Hoang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Wai-Hong Tham
- Infectious Diseases and Immune Defence Division, Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Julian C. Rayner
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Kézia KG Scopel
- Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Josué C. Lima-Junior
- Laboratory of Immunoparasitology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil
| | - Tuan M. Tran
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Microbiology and Immunology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Ryan White Center for Pediatric Infectious Diseases and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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Torres K, Ferreira MU, Castro MC, Escalante AA, Conn JE, Villasis E, da Silva Araujo M, Almeida G, Rodrigues PT, Corder RM, Fernandes ARJ, Calil PR, Ladeia WA, Garcia-Castillo SS, Gomez J, do Valle Antonelli LR, Gazzinelli RT, Golenbock DT, Llanos-Cuentas A, Gamboa D, Vinetz JM. Malaria Resilience in South America: Epidemiology, Vector Biology, and Immunology Insights from the Amazonian International Center of Excellence in Malaria Research Network in Peru and Brazil. Am J Trop Med Hyg 2022; 107:168-181. [PMID: 36228921 PMCID: PMC9662219 DOI: 10.4269/ajtmh.22-0127] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/28/2022] [Indexed: 11/07/2022] Open
Abstract
The 1990s saw the rapid reemergence of malaria in Amazonia, where it remains an important public health priority in South America. The Amazonian International Center of Excellence in Malaria Research (ICEMR) was designed to take a multidisciplinary approach toward identifying novel malaria control and elimination strategies. Based on geographically and epidemiologically distinct sites in the Northeastern Peruvian and Western Brazilian Amazon regions, synergistic projects integrate malaria epidemiology, vector biology, and immunology. The Amazonian ICEMR's overarching goal is to understand how human behavior and other sociodemographic features of human reservoirs of transmission-predominantly asymptomatically parasitemic people-interact with the major Amazonian malaria vector, Nyssorhynchus (formerly Anopheles) darlingi, and with human immune responses to maintain malaria resilience and continued endemicity in a hypoendemic setting. Here, we will review Amazonian ICEMR's achievements on the synergies among malaria epidemiology, Plasmodium-vector interactions, and immune response, and how those provide a roadmap for further research, and, most importantly, point toward how to achieve malaria control and elimination in the Americas.
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Affiliation(s)
- Katherine Torres
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Marcia C. Castro
- Department of Global Health and Population, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Ananias A. Escalante
- Department of Biology and Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, Pennsylvania
| | - Jan E. Conn
- Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, New York
- Wadsworth Center, New York State Department of Health, Albany, New York
| | - Elizabeth Villasis
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Gregorio Almeida
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - Priscila T. Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Rodrigo M. Corder
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Anderson R. J. Fernandes
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Priscila R. Calil
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Winni A. Ladeia
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Stefano S. Garcia-Castillo
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joaquin Gomez
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Ricardo T. Gazzinelli
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
- Division of Infectious Disease and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Douglas T. Golenbock
- Division of Infectious Disease and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Alejandro Llanos-Cuentas
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Dionicia Gamboa
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M. Vinetz
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
- Address correspondence to Joseph M. Vinetz, Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, 25 York St., Winchester 403D, PO Box 802022, New Haven, CT 06520. E-mail:
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10
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Zimmerman RH, Galardo AKR, Lounibos LP, Galardo C, Bahar AK, van Santen E. Vectorial capacities for malaria in eastern Amazonian Brazil depend on village, vector species, season, and parasite species. Malar J 2022; 21:237. [PMID: 35974410 PMCID: PMC9382821 DOI: 10.1186/s12936-022-04255-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The vector species in the Amazon River Basin are regionally and locally diverse, which makes it imperative to understand and compare their roles in malaria transmission to help select appropriate methods of intervention and evaluation. The major aim of this study was to measure the vectorial capacity of five Anopheles species in three neighbouring villages, for two Plasmodium parasite species affecting humans. METHODS From 32 consecutive months of sampling in three villages, 1.5-7.0 km apart, on the Matapi River, Amapá State, Brazil, vectorial capacities (C) were estimated as time series for An. darlingi, An. marajoara, An. nuneztovari, An. triannulatus, and An. intermedius. Monthly parity measurements for each vector species were used to estimate daily survivorship and compared to estimates of survivorship from mark-release-recapture experiments. Gonotrophic cycle lengths were estimated through a time-series analysis of parity data, and durations of sporogony at study site temperatures for the two malaria parasite species were estimated from previous literature. RESULTS The absolute abundances of five vector species were strongly tracked by the spatial variation in C among villages. Temporally, C varied between wet and dry seasons, with An. darlingi, An. marajoara and An. triannulatus exhibiting higher C in the dry season from August to December, and An. nuneztovari its highest C early in the rainy season in January and February. Anopheles intermedius exhibited higher C in the rainy season from April to June than in the dry season. Significant differences in overall survival for each independent variable, and a significant difference in C between wet and dry seasons, among villages, and among vector species for both Plasmodium falciparum and Plasmodium vivax. A generalized linear mixed model (GLMM) analysis by village showed significant effects of vector species on C in only one village, but significant effects of parasite species in all three. Although the GLMM analysis detected no significant parasite x vector species interaction effects on C, effects on C of spline regressions of C dynamics x vector species interactions were significant in all villages. CONCLUSIONS These detailed analyses of entomological and parasitological variables revealed hidden complexities of malaria epidemiology at local scales in neighbouring riverine villages of the Amazon Region.
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Affiliation(s)
- Robert H. Zimmerman
- Florida Medical Entomology Laboratory, University of Florida/IFAS, 200 9th Street SE, Vero Beach, FL 32962 USA
| | - Allan K. R. Galardo
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas E Tecnológicas Do Estado de Amapá-IEPA, Campus do IEPA da Fazendinha-CEP, Macapá, 68912-250 Brazil
| | - L Philip Lounibos
- Florida Medical Entomology Laboratory, University of Florida/IFAS, 200 9th Street SE, Vero Beach, FL 32962 USA
| | - Clicia Galardo
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas E Tecnológicas Do Estado de Amapá-IEPA, Campus do IEPA da Fazendinha-CEP, Macapá, 68912-250 Brazil
| | | | - Edzard van Santen
- Agronomy Department and Statistical Consulting Unit, University of Florida/IFAS, Gainesville, FL 32611 USA
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Cross-border malaria in the triple border region between Brazil, Venezuela and Guyana. Sci Rep 2022; 12:1200. [PMID: 35075191 PMCID: PMC8786846 DOI: 10.1038/s41598-022-05205-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 12/09/2021] [Indexed: 11/08/2022] Open
Abstract
The state of Roraima, in Brazil, has recently seen an increase in the number of reported Plasmodium falciparum infections believed to be imported from neighboring countries. The objective of this study was to determine the prevalence of Plasmodium species among patients attending malaria health posts in Roraima and quantify the infections attributable to imported malaria. This cross-sectional case study was carried out between March 2016 and September 2018. Study participants were recruited as they exited the malaria health post. Information about residence, occupation and travel history was collected using a questionnaire. A dried blood spot was collected and used for malaria diagnosis by PCR. A total of 1222 patients were enrolled. Of the 80% Plasmodium positive samples, 50% were P. falciparum, 34% P. vivax, 8% mixed P. falciparum/P. vivax and 0.2% mixed P. falciparum/P. ovale infections and 8% tested positive for Plasmodium, but the species could not be identified. 80% of the malaria patients likely acquired infections in Venezuela and the remaining 20% acquired in Guyana, Brazil, Suriname and French Guyana. 50% of the study participants reported to be working in a mine. Results from this study support the hypothesis that imported malaria contribute to the bulk of malaria diagnosed in Roraima. These findings are in keeping with previous findings and should be considered when developing malaria control interventions.
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12
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Ferreira MU, Corder RM, Johansen IC, Kattenberg JH, Moreno M, Rosas-Aguirre A, Ladeia-Andrade S, Conn JE, Llanos-Cuentas A, Gamboa D, Rosanas-Urgell A, Vinetz JM. Relative contribution of low-density and asymptomatic infections to Plasmodium vivax transmission in the Amazon: pooled analysis of individual participant data from population-based cross-sectional surveys. LANCET REGIONAL HEALTH. AMERICAS 2022; 9:100169. [PMID: 35663000 PMCID: PMC9161731 DOI: 10.1016/j.lana.2021.100169] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background Low-density and asymptomatic Plasmodium vivax infections remain largely undetected and untreated and may contribute significantly to malaria transmission in the Amazon. Methods We analysed individual participant data from population-based surveys that measured P vivax prevalence by microscopy and polymerase chain reaction (PCR) between 2002 and 2015 and modelled the relationship between parasite density and infectiousness to vectors using membrane feeding assay data. We estimated the proportion of sub-patent (i.e., missed by microscopy) and asymptomatic P vivax infections and examined how parasite density relates to clinical manifestations and mosquito infection in Amazonian settings. Findings We pooled 24,986 observations from six sites in Brazil and Peru. P vivax was detected in 6·8% and 2·1% of them by PCR and microscopy, respectively. 58·5% to 92·6% of P vivax infections were asymptomatic and 61·2% to 96·3% were sub-patent across study sites. P vivax density thresholds associated with clinical symptoms were one order of magnitude higher in children than in adults. We estimate that sub-patent parasite carriers are minimally infectious and contribute 12·7% to 24·9% of the community-wide P vivax transmission, while asymptomatic carriers are the source of 28·2% to 79·2% of mosquito infections. Interpretation Asymptomatic P vivax carriers constitute a vast infectious reservoir that, if targeted by malaria elimination strategies, could substantially reduce malaria transmission in the Amazon. Infected children may remain asymptomatic despite high parasite densities that elicit clinical manifestations in adults. Funding US National Institutes of Health, Fundação de Amparo à Pesquisa do Estado de São Paulo, and Belgium Development Cooperation.
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Affiliation(s)
- Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil,Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, Nova University of Lisbon, Lisbon, Portugal,Corresponding author: Prof Marcelo U. Ferreira, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil.
| | - Rodrigo M. Corder
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Igor C. Johansen
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | | - Marta Moreno
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Angel Rosas-Aguirre
- Institute of Health and Society, Université catholique de Louvain, Brussels, Belgium
| | - Simone Ladeia-Andrade
- Laboratory of Parasitic Diseases, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Brazil
| | - Jan E. Conn
- Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY, USA,Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina Tropical "Alexander von Humboldt", Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Dionicia Gamboa
- Instituto de Medicina Tropical "Alexander von Humboldt", Universidad Peruana Cayetano Heredia, Lima, Peru,Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Anna Rosanas-Urgell
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Joseph M. Vinetz
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru,Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
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Johansen IC, Rodrigues PT, Tonini J, Vinetz J, Castro MC, Ferreira MU. Cohort profile: the Mâncio Lima cohort study of urban malaria in Amazonian Brazil. BMJ Open 2021; 11:e048073. [PMID: 34789490 PMCID: PMC8727682 DOI: 10.1136/bmjopen-2020-048073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 10/22/2021] [Indexed: 01/21/2023] Open
Abstract
PURPOSE This population-based open cohort study aims to investigate biological and sociodemographic drivers of malaria transmission in the main urban hotspot of Amazonian Brazil. PARTICIPANTS Nearly 20% of the households in the northwestern town of Mâncio Lima were randomly selected and 2690 participants were enrolled since April 2018. Sociodemographic, housing quality, occupational, behavioural and morbidity information and travel histories were collected during consecutive study visits. Blood samples from participants>3 months old were used for malaria diagnosis and human genetic studies; samples from participants with laboratory-confirmed malaria have been cryopreserved for genetic and phenotypic characterisation of parasites. Serology was introduced in 2020 to measure the prevalence and longevity of SARS-CoV-2 IgG antibodies. FINDINGS TO DATE Malaria prevalence rates were low (up to 1.0% for Plasmodium vivax and 0.6% for P. falciparum) during five consecutive cross-sectional surveys between April-May 2018 and October-November 2020; 63% of infections diagnosed by microscopy were asymptomatic. Malaria risk is heterogeneously distributed, with 20% study participants contributing 86% of the overall burden of P. vivax infection. Adult males are at greatest risk of infection and human mobility across the urban-rural interface may contribute to sustained malaria transmission. Local P. vivax parasites are genetically diverse and fragmented into discrete inbred lineages that remain stable across space and time. FUTURE PLANS Two follow-up visits, with similar study protocols, are planned in 2021. We aim to identify high-risk individuals that fuel onwards malaria transmission and represent a priority target for more intensive and effective control interventions. TRIAL REGISTRATION NUMBER NCT03689036.
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Affiliation(s)
| | | | - Juliana Tonini
- Parasitology, University of Sao Paulo, Sao Paulo, Brazil
| | - Joseph Vinetz
- Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Marcia C Castro
- Global Health and Population, Harvard School of Public Health, Boston, Massachusetts, USA
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Genetic Diversity of Plasmodium vivax Cysteine-Rich Protective Antigen (PvCyRPA) in Field Isolates from Five Different Areas of the Brazilian Amazon. Genes (Basel) 2021; 12:genes12111657. [PMID: 34828264 PMCID: PMC8623135 DOI: 10.3390/genes12111657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/27/2021] [Accepted: 09/27/2021] [Indexed: 11/16/2022] Open
Abstract
The Plasmodium vivax Cysteine-Rich Protective Antigen (PvCyRPA) has an important role in erythrocyte invasion and has been considered a target for vivax malaria vaccine development. Nonetheless, its genetic diversity remains uncharted in Brazilian malaria-endemic areas. Therefore, we investigated the pvcyrpa genetic polymorphism in 98 field isolates from the Brazilian Amazon and its impact on the antigenicity of predicted B-cell epitopes. Genetic diversity parameters, population genetic analysis, neutrality test and the median-joining network were analyzed, and the potential amino acid polymorphism participation in B-cell epitopes was investigated. One synonymous and 26 non-synonymous substitutions defined fifty haplotypes. The nucleotide diversity and Tajima’s D values varied across the coding gene. The exon-1 sequence had greater diversity than those of exon-2. Concerning the prediction analysis, seven sequences were predicted as linear B cell epitopes, the majority contained in conformational epitopes. Moreover, important amino acid polymorphism was detected in regions predicted to contain residues participating in B-cell epitopes. Our data suggest that the pvcyrpa gene presents a moderate polymorphism in the studied isolates and such polymorphisms alter amino acid sequences contained in potential B cell epitopes, an important observation considering the antigen potentiality as a vaccine candidate to cover distinct P. vivax endemic areas worldwide.
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Dao F, Djonor SK, Ayin CTM, Adu GA, Sarfo B, Nortey P, Akuffo KO, Danso-Appiah A. Burden of malaria in children under five and caregivers' health-seeking behaviour for malaria-related symptoms in artisanal mining communities in Ghana. Parasit Vectors 2021; 14:418. [PMID: 34419123 PMCID: PMC8380373 DOI: 10.1186/s13071-021-04919-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 08/02/2021] [Indexed: 01/21/2023] Open
Abstract
Background Artisanal mining creates enabling breeding ground for the vector of malaria parasites. There is paucity of data on the effects of artisanal mining on malaria. This study assessed burden of malaria and caregivers’ health-seeking behaviour for children under five in artisanal mining communities in East Akim District in Ghana. Methods A cross-sectional study involving caregivers and their children under five was conducted in three artisanal mining communities in the East Akim District in Ghana. Caregivers were interviewed using a structured questionnaire. Finger prick blood samples were collected and analysed for haemoglobin concentration using a rapid diagnostic test, and thick and thin blood smears were analysed to confirm the presence of malaria parasites. Results Of the 372 children under 5 years included in the study, 197 (53.1%) were male, with a mean age (± SD) of 23.0 ± 12.7 months. The proportion of children with malaria (Plasmodium falciparum and P. malariae) was 98.1% and 1.9%, respectively, whilst the proportion with anaemia (Hb < 11.0 g/dl) was 39.5% (n = 147). Almost all caregivers were female (98.9%), and 28.6% (n = 106) did not have access to any malaria control information. Caregivers associated malaria infection with mosquito bites (68.3%, n = 254) and poor sanitation (21.2%, n = 79). Malaria in children under five was significantly associated with anaemia (OR 11.07, 95% CI 6.59–18.68, n = 111/160, 69.4%; P < 0.0001), residing close to stagnant water (≤ 25 m) from an artisanal mining site (AOR 2.91, 95% CI 1.47–5.76, P = 0.002) and caregiver age younger than 30 years (OR 0.44, 95% CI 0.208–0.917, n = 162, 43.55%, P = 0.001). Conclusions There is a high burden of malaria and anaemia among children under five in artisanal mining communities of the East Akim District, and far higher than in non-artisanal mining sites. Interventions are needed to effectively regulate mining activities in these communities, and strengthen malaria control and health education campaigns to curtail the high malaria burden and improve health-seeking behaviour. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04919-8.
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Affiliation(s)
- Francois Dao
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana.,Malaria Research and Training Center, Department of Epidemiology and Infectious Diseases, University of Science Techniques and Technologies of Bamako, Bamako, Mali
| | - Sampson Kafui Djonor
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana
| | - Christian Teye-Muno Ayin
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana
| | | | - Bismark Sarfo
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana
| | - Pricillia Nortey
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana
| | - Kwadwo Owusu Akuffo
- Department of Optometry and Visual Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Anthony Danso-Appiah
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana. .,University of Ghana Centre for Evidence Synthesis and Policy, School of Public Health, University of Ghana, Legon, Ghana.
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Carrillo-Bilbao G, Martin-Solano S, Saegerman C. Zoonotic Blood-Borne Pathogens in Non-Human Primates in the Neotropical Region: A Systematic Review. Pathogens 2021; 10:1009. [PMID: 34451473 PMCID: PMC8400055 DOI: 10.3390/pathogens10081009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/29/2021] [Accepted: 08/05/2021] [Indexed: 01/17/2023] Open
Abstract
Background: Understanding which non-human primates (NHPs) act as a wild reservoir for blood-borne pathogens will allow us to better understand the ecology of diseases and the role of NHPs in the emergence of human diseases in Ecuador, a small country in South America that lacks information on most of these pathogens. Methods and principal findings: A systematic review was carried out using PRISMA guidelines from 1927 until 2019 about blood-borne pathogens present in NHPs of the Neotropical region (i.e., South America and Middle America). Results: A total of 127 publications were found in several databases. We found in 25 genera (132 species) of NHPs a total of 56 blood-borne pathogens in 197 records where Protozoa has the highest number of records in neotropical NHPs (n = 128) compared to bacteria (n = 12) and viruses (n = 57). Plasmodium brasilianum and Trypanosoma cruzi are the most recorded protozoa in NHP. The neotropical primate genus with the highest number of blood-borne pathogens recorded is Alouatta sp. (n = 32). The use of non-invasive samples for neotropical NHPs remains poor in a group where several species are endangered or threatened. A combination of serological and molecular techniques is common when detecting blood-borne pathogens. Socioecological and ecological risk factors facilitate the transmission of these parasites. Finally, a large number of countries remain unsurveyed, such as Ecuador, which can be of public health importance. Conclusions and significance: NHPs are potential reservoirs of a large number of blood-borne pathogens. In Ecuador, research activities should be focused on bacteria and viruses, where there is a gap of information for neotropical NHPs, in order to implement surveillance programs with regular and effective monitoring protocols adapted to NHPs.
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Affiliation(s)
- Gabriel Carrillo-Bilbao
- Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiège), Fundamental and Applied Research for Animal and Health (FARAH) Center, Department of Infections and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium;
- Facultad de Filosofía y Letras y Ciencias de la Educación, Universidad Central del Ecuador, 170521 Quito, Ecuador
- Instituto de Investigación en Zoonosis (CIZ), Universidad Central del Ecuador, 170521 Quito, Ecuador;
| | - Sarah Martin-Solano
- Instituto de Investigación en Zoonosis (CIZ), Universidad Central del Ecuador, 170521 Quito, Ecuador;
- Grupo de Investigación en Sanidad Animal y Humana (GISAH), Carrera Ingeniería en Biotecnología, Departamento de Ciencias de la Vida y la Agricultura, Universidad de las Fuerzas Armadas—ESPE, 171103 Sangolquí, Ecuador
| | - Claude Saegerman
- Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiège), Fundamental and Applied Research for Animal and Health (FARAH) Center, Department of Infections and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium;
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17
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Gimenez AM, Marques RF, Regiart M, Bargieri DY. Diagnostic Methods for Non-Falciparum Malaria. Front Cell Infect Microbiol 2021; 11:681063. [PMID: 34222049 PMCID: PMC8248680 DOI: 10.3389/fcimb.2021.681063] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/31/2021] [Indexed: 11/13/2022] Open
Abstract
Malaria is a serious public health problem that affects mostly the poorest countries in the world, killing more than 400,000 people per year, mainly children under 5 years old. Among the control and prevention strategies, the differential diagnosis of the Plasmodium-infecting species is an important factor for selecting a treatment and, consequently, for preventing the spread of the disease. One of the main difficulties for the detection of a specific Plasmodium sp is that most of the existing methods for malaria diagnosis focus on detecting P. falciparum. Thus, in many cases, the diagnostic methods neglect the other non-falciparum species and underestimate their prevalence and severity. Traditional methods for diagnosing malaria may present low specificity or sensitivity to non-falciparum spp. Therefore, there is high demand for new alternative methods able to differentiate Plasmodium species in a faster, cheaper and easier manner to execute. This review details the classical procedures and new perspectives of diagnostic methods for malaria non-falciparum differential detection and the possibilities of their application in different circumstances.
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Affiliation(s)
- Alba Marina Gimenez
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rodolfo F. Marques
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Matías Regiart
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Daniel Youssef Bargieri
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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18
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Laporta GZ, Ilacqua RC, Bergo ES, Chaves LSM, Rodovalho SR, Moresco GG, Figueira EAG, Massad E, de Oliveira TMP, Bickersmith SA, Conn JE, Sallum MAM. Malaria transmission in landscapes with varying deforestation levels and timelines in the Amazon: a longitudinal spatiotemporal study. Sci Rep 2021; 11:6477. [PMID: 33742028 PMCID: PMC7979798 DOI: 10.1038/s41598-021-85890-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 03/08/2021] [Indexed: 01/31/2023] Open
Abstract
The relationship between deforestation and malaria is a spatiotemporal process of variation in Plasmodium incidence in human-dominated Amazonian rural environments. The present study aimed to assess the underlying mechanisms of malarial exposure risk at a fine scale in 5-km2 sites across the Brazilian Amazon, using field-collected data with a longitudinal spatiotemporally structured approach. Anopheline mosquitoes were sampled from 80 sites to investigate the Plasmodium infection rate in mosquito communities and to estimate the malaria exposure risk in rural landscapes. The remaining amount of forest cover (accumulated deforestation) and the deforestation timeline were estimated in each site to represent the main parameters of both the frontier malaria hypothesis and an alternate scenario, the deforestation-malaria hypothesis, proposed herein. The maximum frequency of pathogenic sites occurred at the intermediate forest cover level (50% of accumulated deforestation) at two temporal deforestation peaks, e.g., 10 and 35 years after the beginning of the organization of a settlement. The incidence density of infected anophelines in sites where the original forest cover decreased by more than 50% in the first 25 years of settlement development was at least twice as high as the incidence density calculated for the other sites studied (adjusted incidence density ratio = 2.25; 95% CI, 1.38-3.68; p = 0.001). The results of this study support the frontier malaria as a unifying hypothesis for explaining malaria emergence and for designing specific control interventions in the Brazilian Amazon.
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Affiliation(s)
- Gabriel Z Laporta
- Setor de Pós-Graduação, Pesquisa e Inovação, Centro Universitário Saúde ABC (FMABC), Fundação ABC, Santo André, SP, Brazil.
| | - Roberto C Ilacqua
- Setor de Pós-Graduação, Pesquisa e Inovação, Centro Universitário Saúde ABC (FMABC), Fundação ABC, Santo André, SP, Brazil
| | - Eduardo S Bergo
- Superintendência de Controle de Endemias (SUCEN), Secretaria de Estado da Saúde de São Paulo, Araraquara, SP, Brazil
| | - Leonardo S M Chaves
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo (FSP-USP), São Paulo, SP, Brazil
| | - Sheila R Rodovalho
- Unidade Técnica de Doenças Transmissíveis e Análise de Situação em Saúde, Pan American Health Organization (PAHO/WHO), Brasília, DF, Brazil
| | - Gilberto G Moresco
- Coordenação-Geral de Vigilância de Zoonoses e Doenças de Transmissão Vetorial, Secretaria de Vigilância em Saúde, Ministério da Saúde (MS), Brasília, DF, Brazil
| | | | - Eduardo Massad
- Escola de Matemática Aplicada, Fundação Getúlio Vargas, Rio de Janeiro, RJ, Brazil
| | - Tatiane M P de Oliveira
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo (FSP-USP), São Paulo, SP, Brazil
| | - Sara A Bickersmith
- New York State Department of Health, The Wadsworth Center, Slingerlands, NY, USA
| | - Jan E Conn
- New York State Department of Health, The Wadsworth Center, Slingerlands, NY, USA
- Department of Biomedical Sciences, School of Public Health, State University of New York, Albany, NY, USA
| | - Maria Anice M Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo (FSP-USP), São Paulo, SP, Brazil.
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19
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Rosas-Aguirre A, Guzman-Guzman M, Chuquiyauri R, Moreno M, Manrique P, Ramirez R, Carrasco-Escobar G, Rodriguez H, Speybroeck N, Conn JE, Gamboa D, Vinetz JM, Llanos-Cuentas A. Temporal and Microspatial Heterogeneity in Transmission Dynamics of Coendemic Plasmodium vivax and Plasmodium falciparum in Two Rural Cohort Populations in the Peruvian Amazon. J Infect Dis 2020; 223:1466-1477. [PMID: 32822474 DOI: 10.1093/infdis/jiaa526] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/17/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Malaria is highly heterogeneous: its changing malaria microepidemiology needs to be addressed to support malaria elimination efforts at the regional level. METHODS A 3-year, population-based cohort study in 2 settings in the Peruvian Amazon (Lupuna, Cahuide) followed participants by passive and active case detection from January 2013 to December 2015. Incidence and prevalence rates were estimated using microscopy and polymerase chain reaction (PCR). RESULTS Lupuna registered 1828 infections (1708 Plasmodium vivax, 120 Plasmodium falciparum; incidence was 80.7 infections/100 person-years (95% confidence interval [CI] , 77.1-84.5). Cahuide detected 1046 infections (1024 P vivax, 20 P falciparum, 2 mixed); incidence was 40.2 infections/100 person-years (95% CI, 37.9-42.7). Recurrent P vivax infections predominated onwards from 2013. According to PCR data, submicroscopic predominated over microscopic infections, especially in periods of low transmission. The integration of parasitological, entomological, and environmental observations evidenced an intense and seasonal transmission resilient to standard control measures in Lupuna and a persistent residual transmission after severe outbreaks were intensively handled in Cahuide. CONCLUSIONS In 2 exemplars of complex local malaria transmission, standard control strategies failed to eliminate submicroscopic and hypnozoite reservoirs, enabling persistent transmission.
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Affiliation(s)
- Angel Rosas-Aguirre
- Research Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium.,Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Mitchel Guzman-Guzman
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú.,Laboratorio International Centers of Excellence in Malaria Research-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Raul Chuquiyauri
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú.,Laboratorio International Centers of Excellence in Malaria Research-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Marta Moreno
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California, USA.,London School of Hygiene and Tropical Medicine, Department of Immunology and Infection, London, United Kingdom
| | - Paulo Manrique
- Laboratorio International Centers of Excellence in Malaria Research-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Roberson Ramirez
- Laboratorio International Centers of Excellence in Malaria Research-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Gabriel Carrasco-Escobar
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú.,Laboratorio International Centers of Excellence in Malaria Research-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú.,Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Hugo Rodriguez
- Dirección Regional de Salud Loreto DIRESA Loreto, Loreto, Perú
| | - Niko Speybroeck
- Research Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
| | - Jan E Conn
- Wadsworth Center, New York State Department of Health, Albany, New York, USA.,Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, New York, USA
| | - Dionicia Gamboa
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú.,Laboratorio International Centers of Excellence in Malaria Research-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú.,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Joseph M Vinetz
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú.,Laboratorio International Centers of Excellence in Malaria Research-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú.,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú.,Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú.,Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Perú
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20
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Melo J, Padilha M, Barbosa R, Alonso W, Vittor A, Laporta G. Evaluation of the malaria elimination policy in Brazil: a systematic review and epidemiological analysis study. Trop Biomed 2020; 37:513-535. [PMID: 33235398 PMCID: PMC7682744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
After a centenary fight against malaria, Brazil has seen an opportunity for change with the proposal of the malaria elimination policy set by the Brazilian government, in line with malaria elimination policies in other Latin American countries. Brazilian malaria experts regard eliminating malaria by 2030 to be within reach. Herein we evaluated the likelihood that malaria elimination can be accomplished in Brazil through systematic review of the literature on malaria elimination in Brazil and epidemiological analysis. Fifty-two articles referring to malaria eradication/elimination in Brazil were analyzed to identify challenges and technological breakthroughs for controlling malaria. Monthly deaths (1979-2016) and monthly severe malaria cases (1998-2018) were analyzed according to age groups, geographic region and parasite species. As a result, we observed that the declining malaria burden was mostly attributable to a decline in Plasmodium falciparum-malaria. At the same time, the proportional increase of Plasmodium vivax-malaria in comparison with P. falciparum-malaria was notable. This niche replacement mechanism was discussed in the reviewed literature. In addition, the challenges to P. vivax-malaria elimination outnumbered the available technological breakthroughs. Although accumulated and basic information exists on mosquito vector biology, the lack of specific knowledge about mosquito vector taxonomy and ecology may hamper current attempts at stopping malaria in the country. An impressive reduction in malaria hospitalizations and mortality was seen in Brazil in the past 3 decades. Eliminating malaria deaths in children less than 5 years and P. falciparum severe cases may be achievable goals under the current malaria policy until 2030. However, eliminating P. vivax malaria transmission and morbidity seems unattainable with the available tools. Therefore, complete malaria elimination in Brazil in the near future is unlikely.
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Affiliation(s)
- J.O. Melo
- Setor de Pos-graduaçao, Pesquisa e Inovação, Centro Universitârio Saûde ABC, Fundação do ABC, Santo André, SP, Brazil
| | - M.A.O. Padilha
- Setor de Pos-graduaçao, Pesquisa e Inovação, Centro Universitârio Saûde ABC, Fundação do ABC, Santo André, SP, Brazil
| | - R.T.A. Barbosa
- Setor de Pos-graduaçao, Pesquisa e Inovação, Centro Universitârio Saûde ABC, Fundação do ABC, Santo André, SP, Brazil
| | | | - A.Y. Vittor
- Department of Medicine and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
- Division of Infectious Diseases and Global Medicine, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - G.Z. Laporta
- Setor de Pos-graduaçao, Pesquisa e Inovação, Centro Universitârio Saûde ABC, Fundação do ABC, Santo André, SP, Brazil
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21
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Corder RM, Ferreira MU, Gomes MGM. Modelling the epidemiology of residual Plasmodium vivax malaria in a heterogeneous host population: A case study in the Amazon Basin. PLoS Comput Biol 2020; 16:e1007377. [PMID: 32168349 PMCID: PMC7108741 DOI: 10.1371/journal.pcbi.1007377] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 03/31/2020] [Accepted: 01/29/2020] [Indexed: 02/07/2023] Open
Abstract
The overall malaria burden in the Americas has decreased dramatically over the past two decades, but residual transmission pockets persist across the Amazon Basin, where Plasmodium vivax is the predominant infecting species. Current elimination efforts require a better quantitative understanding of malaria transmission dynamics for planning, monitoring, and evaluating interventions at the community level. This can be achieved with mathematical models that properly account for risk heterogeneity in communities approaching elimination, where few individuals disproportionately contribute to overall malaria prevalence, morbidity, and onwards transmission. Here we analyse demographic information combined with routinely collected malaria morbidity data from the town of Mâncio Lima, the main urban transmission hotspot of Brazil. We estimate the proportion of high-risk subjects in the host population by fitting compartmental susceptible-infected-susceptible (SIS) transmission models simultaneously to age-stratified vivax malaria incidence densities and the frequency distribution of P. vivax malaria attacks experienced by each individual over 12 months. Simulations with the best-fitting SIS model indicate that 20% of the hosts contribute 86% of the overall vivax malaria burden. Despite the low overall force of infection typically found in the Amazon, about one order of magnitude lower than that in rural Africa, high-risk individuals gradually develop clinical immunity following repeated infections and eventually constitute a substantial infectious reservoir comprised of asymptomatic parasite carriers that is overlooked by routine surveillance but likely fuels onwards malaria transmission. High-risk individuals therefore represent a priority target for more intensive and effective interventions that may not be readily delivered to the entire community.
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Affiliation(s)
- Rodrigo M. Corder
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail: (RMC); (MGMG)
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - M. Gabriela M. Gomes
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, and CMUP, Centro de Matemática da Universidade do Porto, Porto, Portugal
- * E-mail: (RMC); (MGMG)
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22
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Knudson A, González-Casabianca F, Feged-Rivadeneira A, Pedreros MF, Aponte S, Olaya A, Castillo CF, Mancilla E, Piamba-Dorado A, Sanchez-Pedraza R, Salazar-Terreros MJ, Lucchi N, Udhayakumar V, Jacob C, Pance A, Carrasquilla M, Apráez G, Angel JA, Rayner JC, Corredor V. Spatio-temporal dynamics of Plasmodium falciparum transmission within a spatial unit on the Colombian Pacific Coast. Sci Rep 2020; 10:3756. [PMID: 32111872 PMCID: PMC7048816 DOI: 10.1038/s41598-020-60676-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 01/29/2020] [Indexed: 02/07/2023] Open
Abstract
As malaria control programmes concentrate their efforts towards malaria elimination a better understanding of malaria transmission patterns at fine spatial resolution units becomes necessary. Defining spatial units that consider transmission heterogeneity, human movement and migration will help to set up achievable malaria elimination milestones and guide the creation of efficient operational administrative control units. Using a combination of genetic and epidemiological data we defined a malaria transmission unit as the area contributing 95% of malaria cases diagnosed at the catchment facility located in the town of Guapi in the South Pacific Coast of Colombia. We provide data showing that P. falciparum malaria transmission is heterogeneous in time and space and analysed, using topological data analysis, the spatial connectivity, at the micro epidemiological level, between parasite populations circulating within the unit. To illustrate the necessity to evaluate the efficacy of malaria control measures within the transmission unit in order to increase the efficiency of the malaria control effort, we provide information on the size of the asymptomatic reservoir, the nature of parasite genotypes associated with drug resistance as well as the frequency of the Pfhrp2/3 deletion associated with false negatives when using Rapid Diagnostic Tests.
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Affiliation(s)
- Angélica Knudson
- Departamento de Microbiología, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Felipe González-Casabianca
- Departamento de Matemáticas, Facultad de Ciencias, Universidad de Los Andes, Bogotá, Colombia.,Gestión y desarrollo urbanos, Facultad de Ciencia Política, Universidad del Rosario, Bogotá, Colombia
| | | | - Maria Fernanda Pedreros
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Samanda Aponte
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Adriana Olaya
- Secretaría Departamental de Salud del Cauca, Popayán, Colombia
| | | | - Elvira Mancilla
- Secretaría Departamental de Salud del Cauca, Popayán, Colombia
| | | | - Ricardo Sanchez-Pedraza
- Departamento de Psiquiatria, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Myriam Janeth Salazar-Terreros
- Post-doctoral fellow, Centro de Hematologia e Hemoterapia (HEMOCENTRO), Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
| | - Naomi Lucchi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Global Health, Centers for Disease Control and Prevention, Atlanta, 30030, GA, United States of America
| | - Venkatachalam Udhayakumar
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Global Health, Centers for Disease Control and Prevention, Atlanta, 30030, GA, United States of America
| | - Chris Jacob
- Malaria Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, CB10 1SA, United Kingdom
| | - Alena Pance
- Malaria Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, CB10 1SA, United Kingdom
| | - Manuela Carrasquilla
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, 02115, USA
| | - Giovanni Apráez
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia.,Secretaría Departamental de Salud del Cauca, Popayán, Colombia
| | - Jairo Andrés Angel
- Departamento de Matemáticas, Facultad de Ciencias, Universidad de Los Andes, Bogotá, Colombia.,Department of Mathematics and Statistics, Universidad del Norte, Barranquilla, Colombia
| | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, United Kingdom.
| | - Vladimir Corredor
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia.
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23
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Antonelli LR, Junqueira C, Vinetz JM, Golenbock DT, Ferreira MU, Gazzinelli RT. The immunology of Plasmodium vivax malaria. Immunol Rev 2019; 293:163-189. [PMID: 31642531 DOI: 10.1111/imr.12816] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 09/10/2019] [Indexed: 12/13/2022]
Abstract
Plasmodium vivax infection, the predominant cause of malaria in Asia and Latin America, affects ~14 million individuals annually, with considerable adverse effects on wellbeing and socioeconomic development. A clinical hallmark of Plasmodium infection, the paroxysm, is driven by pyrogenic cytokines produced during the immune response. Here, we review studies on the role of specific immune cell types, cognate innate immune receptors, and inflammatory cytokines on parasite control and disease symptoms. This review also summarizes studies on recurrent infections in individuals living in endemic regions as well as asymptomatic infections, a serious barrier to eliminating this disease. We propose potential mechanisms behind these repeated and subclinical infections, such as poor induction of immunological memory cells and inefficient T effector cells. We address the role of antibody-mediated resistance to P. vivax infection and discuss current progress in vaccine development. Finally, we review immunoregulatory mechanisms, such as inhibitory receptors, T regulatory cells, and the anti-inflammatory cytokine, IL-10, that antagonizes both innate and acquired immune responses, interfering with the development of protective immunity and parasite clearance. These studies provide new insights for the clinical management of symptomatic as well as asymptomatic individuals and the development of an efficacious vaccine for vivax malaria.
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Affiliation(s)
- Lis R Antonelli
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - Caroline Junqueira
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - Joseph M Vinetz
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Douglas T Golenbock
- Division of Infectious Disease and immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Marcelo U Ferreira
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Ricardo T Gazzinelli
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil.,Division of Infectious Disease and immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA.,Plataforma de Medicina Translacional, Fundação Oswaldo Cruz, Ribeirão Preto, Brazil
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24
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Humoral immunity prevents clinical malaria during Plasmodium relapses without eliminating gametocytes. PLoS Pathog 2019; 15:e1007974. [PMID: 31536608 PMCID: PMC6752766 DOI: 10.1371/journal.ppat.1007974] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 07/10/2019] [Indexed: 12/19/2022] Open
Abstract
Plasmodium relapses are attributed to the activation of dormant liver-stage parasites and are responsible for a significant number of recurring malaria blood-stage infections. While characteristic of human infections caused by P. vivax and P. ovale, their relative contribution to malaria disease burden and transmission remains poorly understood. This is largely because it is difficult to identify ‘bona fide’ relapse infections due to ongoing transmission in most endemic areas. Here, we use the P. cynomolgi–rhesus macaque model of relapsing malaria to demonstrate that clinical immunity can form after a single sporozoite-initiated blood-stage infection and prevent illness during relapses and homologous reinfections. By integrating data from whole blood RNA-sequencing, flow cytometry, P. cynomolgi-specific ELISAs, and opsonic phagocytosis assays, we demonstrate that this immunity is associated with a rapid recall response by memory B cells that expand and produce anti-parasite IgG1 that can mediate parasite clearance of relapsing parasites. The reduction in parasitemia during relapses was mirrored by a reduction in the total number of circulating gametocytes, but importantly, the cumulative proportion of gametocytes increased during relapses. Overall, this study reveals that P. cynomolgi relapse infections can be clinically silent in macaques due to rapid memory B cell responses that help to clear asexual-stage parasites but still carry gametocytes. Plasmodium vivax contributes significantly to global malaria morbidity and remains a major obstacle for malaria elimination due to its ability to form dormant stages in the liver. These forms can become activated to cause relapsing blood-stage infections. Relapses remain poorly understood because it is difficult to verify whether P. vivax blood-stage infections in patients are due to new infections or relapses in most cases. Here, we use a nonhuman primate model of Plasmodium vivax malaria in concert with state-of-the-art immunological and molecular techniques to assess pathogenesis, host responses, and circulating gametocyte levels during relapses. We found that relapses were clinically silent compared to initial infections, and they were associated with a robust memory B cell response. This response resulted in the production of antibodies that were able to mediate clearance of asexual parasites. Despite this rapid immune protection, the sexual-stage gametocytes continued to circulate. Our study provides mechanistic insights into the host-parasite interface during Plasmodium relapse infections and demonstrates that clinically silent relapses can harbor gametocytes that may be infectious to mosquitoes.
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Pizzitutti F, Mena CF, Feingold B, Pan WK. Modeling asymptomatic infections and work-related human circulation as drivers of unstable malaria transmission in low-prevalence areas: A study in the Northern Peruvian Amazon. Acta Trop 2019; 197:104909. [PMID: 30703339 DOI: 10.1016/j.actatropica.2019.01.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 01/17/2019] [Accepted: 01/27/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Despite relatively successful control campaigns, malaria remains a relevant public health problem in the Peruvian Amazon. Several studies suggest that malaria persistence in the area can be connected with a high prevalence of asymptomatic infections, which were subsequently shown to be connected with work-related exposure in areas of hyperendemic transmission. In this study, we tested the hypothesis that the infection reservoir represented by asymptomatic carriers in the northern Peruvian Amazon, combined with circular human movement to and from hyperendemic working areas, can capture the observed hypoendemic malaria transmission. METHODS We designed a set of agent-based models that represent local-scale malaria transmission in a typical riverine community in the northern Peruvian Amazon. The models include asymptomatic individuals as well as a full representation of human movements within the community and between the community and external hyperendemic working places. Several theoretical scenarios are explored to verify if and how malaria clinical immunity prevalence and human work-related movements influence the malaria morbidity registered in the community. RESULTS Agent-based simulations suggest that malaria incidence observed through passive case detection can be reproduced as exclusively generated by the asymptomatic infection reservoir. Scenarios analysis also show that, even if asymptomatic infections are completely eliminated, human movements to and from hyperendemic working areas generate a flow of imported cases that is enough to permit the persistence of transmission in the community. Simulation results were verified over a wide range of clinical immunity prevalence values and over a wide range of percentages of people working in remote hyperendemic areas. This context of unstable malaria transmission is observed to be vulnerable to severe outbreaks. CONCLUSIONS Asymptomatic malaria infection and occupational circular human movement to hyperendemic transmission areas are designated by agent-based models as possible exclusive causes of residual hypoendemic malaria transmission observed in the Peruvian Amazon. Control strategies are proposed to decrease asymptomatic infection prevalence and to block transmission from asymptomatic individuals to the malaria susceptible population.
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SHAHANDEH K, BASSERI HR. Challenges and the Path Forward on Malaria Elimination Intervention: A Systematic Review. IRANIAN JOURNAL OF PUBLIC HEALTH 2019; 48:1004-1013. [PMID: 31341841 PMCID: PMC6635336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND This systematic review was conducted to highlights key challenges, and outlines important next steps to maximize the potential to contribute to the broader malaria elimination interventions. METHODS This systematic review on malaria elimination intervention and challenges was undertaken searching six databases, between 1995 and 2018. Inclusion and exclusion criteria were set. The references were collated and categorized according to type of study, intervention, population, and health outcome. Articles selection based on title and abstract, retrieval of full text and additions of articles from reference lists and recommendations from experts. Disagreement in data extraction was solved by consultation of third reviewer. RESULTS Overall, 4039 records were examined related to malaria elimination that initially identified by our designated electronic databases search. Overall, 35 studies contained 14 experimental studies (40%) and 21 analytic observational studies (60%) met the inclusion criteria for this review. Studies used a wide variety of malaria elimination interventions. Types of interventions either elimination-focused interventions or general interventions on educational, prevention and treatment of malaria are included. This review pointed out the variety of challenges for eliminate malaria among low and high endemic countries. CONCLUSION Malaria elimination is facilitated by strong health systems, determined leadership, appropriate incentivization, an effective surveillance system, and regional collaborations. We have identified areas for elimination-specific interventions deserve more attention in the conduct and reporting.
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Affiliation(s)
- Khandan SHAHANDEH
- Deputy of Research and Technology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Reza BASSERI
- Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,Corresponding Author:
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Baia-da-Silva DC, Brito-Sousa JD, Rodovalho SR, Peterka C, Moresco G, Lapouble OMM, Melo GCD, Sampaio VDS, Alecrim MDGC, Pimenta P, Lima JBP, Lacerda MVGD, Monteiro WM. Current vector control challenges in the fight against malaria in Brazil. Rev Soc Bras Med Trop 2019; 52:e20180542. [PMID: 30843971 DOI: 10.1590/0037-8682-0542-2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 02/20/2019] [Indexed: 11/22/2022] Open
Abstract
In Brazil, malaria is an important public health problem first reported in 1560. Historically, fluctuations in malaria cases in Brazil are attributed to waves of economic development; construction of railroads, highways, and hydroelectric dams; and population displacement and land occupation policies. Vector control measures have been widely used with an important role in reducing malaria cases. In this review article, we reviewed the vector control measures established in the Brazilian territory and aspects associated with such measures for malaria. Although some vector control measures are routinely used in Brazil, many entomological and effectiveness information still need better evidence in endemic areas where Plasmodium vivax predominates. Herein, we outlined some of the needs and priorities for future research: a) update of the cartography of malaria vectors in Brazil, adding molecular techniques for the correct identification of species and complexes of species; b) evaluation of vector competence of anophelines in Brazil; c) strengthening of local entomology teams to perform vector control measures and interpret results; d) evaluation of vector control measures, especially use of insecticide-treated nets and long-lasting insecticidal nets, estimating their effectiveness, cost-benefit, and population acceptance; e) establishment of colonies of malaria vectors in Brazil, i.e., Anopheles darlingi, to understand parasite-vector interactions better; f) study of new vector control strategies with impacts on non-endophilic vectors; g) estimation of the impact of insecticide resistance in different geographical areas; and h) identification of the relative contribution of natural and artificial breeding sites in different epidemiological contexts for transmission.
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Affiliation(s)
- Djane Clarys Baia-da-Silva
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil
| | - José Diego Brito-Sousa
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil
| | - Sheila Rodrigues Rodovalho
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil.,Organização Pan-Americana de Saúde, Brasília, DF, Brasil
| | - Cassio Peterka
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil.,Programa Nacional de Controle da Malária, Ministério da Saúde, Brasília, DF, Brasil
| | - Gilberto Moresco
- Programa Nacional de Controle da Malária, Ministério da Saúde, Brasília, DF, Brasil
| | - Oscar Martín Mesones Lapouble
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil.,Organização Pan-Americana de Saúde, Brasília, DF, Brasil
| | - Gisely Cardoso de Melo
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil
| | - Vanderson de Souza Sampaio
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil.,Fundação de Vigilância em Saúde, Manaus, AM, Brasil
| | - Maria das Graças Costa Alecrim
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil
| | - Paulo Pimenta
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil.,Instituto de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, MG, Brasil
| | | | - Marcus Vinícius Guimarães de Lacerda
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil.,Instituto de Pesquisas Leônidas and Maria Deane, Fundação Oswaldo Cruz, Manaus, AM, Brasil
| | - Wuelton Marcelo Monteiro
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brasil
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Ferreira MU, Castro MC. Malaria Situation in Latin America and the Caribbean: Residual and Resurgent Transmission and Challenges for Control and Elimination. Methods Mol Biol 2019; 2013:57-70. [PMID: 31267493 DOI: 10.1007/978-1-4939-9550-9_4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Despite recent progress toward malaria elimination in Latin America and the Caribbean, with an overall 62% decrease in incidence between 2000 and 2015, malaria remains endemic to 21 countries and territories in the region, where 120 million people are exposed to some risk of infection. Here we review recent epidemiologic trends, highlight current challenges, and briefly discuss the relative role of traditional and novel strategies for better malaria control and elimination across the continent.
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Affiliation(s)
- Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
| | - Marcia C Castro
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA
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29
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Feged-Rivadeneira A, Ángel A, González-Casabianca F, Rivera C. Malaria intensity in Colombia by regions and populations. PLoS One 2018; 13:e0203673. [PMID: 30208075 PMCID: PMC6135511 DOI: 10.1371/journal.pone.0203673] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/26/2018] [Indexed: 12/15/2022] Open
Abstract
Determining the distribution of disease prevalence among heterogeneous populations at the national scale is fundamental for epidemiology and public health. Here, we use a combination of methods (spatial scan statistic, topological data analysis and epidemic profile) to study measurable differences in malaria intensity by regions and populations of Colombia. This study explores three main questions: What are the regions of Colombia where malaria is epidemic? What are the regions and populations in Colombia where malaria is endemic? What associations exist between epidemic outbreaks between regions in Colombia? Plasmodium falciparum is most prevalent in the Pacific Coast, some regions of the Amazon Basin, and some regions of the Magdalena Basin. Plasmodium vivax is the most prevalent parasite in Colombia, particularly in the Northern Amazon Basin, the Caribbean, and municipalities of Sucre, Antioquia and Cordoba. We find an acute peak of malarial infection at 25 years of age. Indigenous and Afrocolombian populations experience endemic malaria (with household transmission). We find that Plasmodium vivax decreased in the most important hotspots, often with moderate urbanization rate, and was re-introduced to locations with moderate but sustained deforestation. Infection by Plasmodium falciparum, on the other hand, steadily increased in incidence in locations where it was introduced in the 2009-2010 generalized epidemic. Our findings suggest that Colombia is entering an unstable transmission state, where rapid decreases in one location of the country are interconnected with rapid increases in other parts of the country.
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Affiliation(s)
- Alejandro Feged-Rivadeneira
- Department of Anthropology, Stanford University, Stanford, CA, United States of America
- Department of Urban Management and Design, Universidad del Rosario, Bogotá, Colombia
- * E-mail:
| | - Andrés Ángel
- Department of Mathematics, Universidad de los Andes, Bogotá, Colombia
- Department of Mathematics and Statistics, Universidad del Norte, Barranquilla, Colombia
| | | | - Camilo Rivera
- Walmartlabs, Sunnyvale, CA, United States of America
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30
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Lover AA, Baird JK, Gosling R, Price RN. Malaria Elimination: Time to Target All Species. Am J Trop Med Hyg 2018; 99:17-23. [PMID: 29761762 PMCID: PMC6035869 DOI: 10.4269/ajtmh.17-0869] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/14/2018] [Indexed: 01/13/2023] Open
Abstract
Important strides have been made within the past decade toward malaria elimination in many regions, and with this progress, the feasibility of eradication is once again under discussion. If the ambitious goal of eradication is to be achieved by 2040, all species of Plasmodium infecting humans will need to be targeted with evidence-based and concerted interventions. In this perspective, the potential barriers to achieving global malaria elimination are discussed with respect to the related diversities in host, parasite, and vector populations. We argue that control strategies need to be reorientated from a sequential attack on each species, dominated by Plasmodium falciparum to one that targets all species in parallel. A set of research themes is proposed to mitigate the potential setbacks on the pathway to a malaria-free world.
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Affiliation(s)
- Andrew A. Lover
- Malaria Elimination Initiative at the University of California, San Francisco, San Francisco, California
| | - J. Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Jakarta, Indonesia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Roly Gosling
- Malaria Elimination Initiative at the University of California, San Francisco, San Francisco, California
| | - Ric N. Price
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
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31
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Brown R, Hing CT, Fornace K, Ferguson HM. Evaluation of resting traps to examine the behaviour and ecology of mosquito vectors in an area of rapidly changing land use in Sabah, Malaysian Borneo. Parasit Vectors 2018; 11:346. [PMID: 29898780 PMCID: PMC6000972 DOI: 10.1186/s13071-018-2926-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/30/2018] [Indexed: 12/22/2022] Open
Abstract
Background Widespread deforestation occurring in the tropics is hypothesized to impact the transmission of vector-borne diseases (VBD). Predicting how environmental changes will impact VBD transmission is dependent on understanding the ecology and behaviour of potential vector species outside of domestic settings. However there are few reliable sampling tools for measuring the habitat preference and host choice of mosquito vectors; with almost none suitable for sampling recently blood-fed, resting mosquitoes. This study evaluated the use of two mosquito traps: the resting bucket (RB) and sticky resting bucket (SRB) traps relative to CDC backpack aspiration (CDC) for sampling mosquitoes resting in a range of habitats representing a gradient of deforestation. Eight habitats were selected for sampling around two villages in Kudat District, Malaysian Borneo, to reflect the range of habitats available to mosquitoes in and around human dwellings, and nearby forest habitats where reservoir hosts are present: secondary forest (edge, interior and canopy); plantations (palm and rubber); and human settlements (inside, under and around houses). Results Over 31 days, 2243 mosquitoes were collected in 5748 discrete collections. Nine mosquito genera were sampled with Aedes and Culex species being present in all habitats and most abundant. RB and CDC backpack aspiration were most efficient for sampling Culex whereas CDC backpack aspiration and SRB were most efficient for Aedes. Most Aedes identified to species level were Ae. albopictus (91%), with their abundance being highest in forest edge habitats. In contrast, Culex were most abundant under houses. Most blood-fed mosquitoes (76%) were found in human settlements; with humans and chickens being the only blood source. Conclusions RB and SRB traps proved capable of sampling mosquitoes resting in all sampled habitats. However, sampling efficiency was generally low (c.0.1 per trap per day), necessitating traps to be deployed in high numbers for mosquito detection. None of the traps were effective for sampling zoonotic malaria vectors; however, SRB collected relatively higher numbers of the dengue vector Ae. albopictus. The higher abundance of mosquitoes in forest edge habitats indicates the potential value of these traps for investigating sylvatic dengue transmission. This study has demonstrated the merits in application of simple resting traps for characterising mosquito vector resting behaviour outside of the home. Electronic supplementary material The online version of this article (10.1186/s13071-018-2926-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rebecca Brown
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Chua Tock Hing
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Sabah, Malaysia
| | - Kimberly Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Heather M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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The Urban Gradient in Malaria-Endemic Municipalities in Acre: Revisiting the Role of Locality. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15061254. [PMID: 29899244 PMCID: PMC6025509 DOI: 10.3390/ijerph15061254] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/08/2018] [Accepted: 05/21/2018] [Indexed: 12/27/2022]
Abstract
Urbanization has altered the distribution of diseases of public health importance along gradients of human occupation. Adopting dichotomous urban/rural categories to explain differences in the risk of exposure, as well as the prevention of diseases is insufficient. In this paper, we present the potential of representations based on the gradient perspective to characterize the living spaces of municipalities where malaria is endemic in northwest Acre. Inventoried data in 40 localities in the Mâncio Lima and Rodrigues Alves municipalities and information on land use and land cover obtained from the TerraClass Database were used to characterize the urban spatial forms and their social content. Results showed a gradient of intensities: from municipal seats to the most connected localities through the road network to riverine communities. Based on the results, we hope to advance the discussion about the use of normative definitions of “urban” and “rural” for public policies and actions to control and eliminate malaria, considering the position of each locality in its own locally referenced urban gradient.
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Feged-Rivadeneira A, Evans S. Ethnography of a parasite: A quantitative ethnographic observation of forest malaria in the Amazon basin. Scand J Public Health 2018; 47:820-831. [PMID: 29783880 DOI: 10.1177/1403494818756561] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aims: Malaria in the Amazon basin is persistently more prevalent among low density populations (1-4 people/km2). Describing malaria transmission in small populations, such as ethnic minorities in the Amazon basin, living in reserves in groups that amount to 110-450 individuals, is fundamental for the implementation of adequate interventions. Here, we examine malaria transmission in a context of high prevalence in a small population of Nükak ethnicity (ethnic group n=400-650 individuals, study group, n=108 individuals) living in the peri-urban area of a city with 35,000 inhabitants in the Amazon basin. Methods: Using methods from behavioral ecology, we conducted a quantitative ethnography and collected data to inform of individual behavioral profiles. Individual malarial infection reports were available from the local public health offices, so each behavioral profile was associated with an epidemic profile for the past 5 years. Results: Our research shows that, in-line with current opinion, malaria among the Nükak is not associated with an occupational hazard risk and follows a holoendemic pattern, where children are most susceptible to the parasite. Parasite loads of malarial infection among the Nükak persist at much higher rates than in any other neighboring ethnicity, which indicates an association between high incidence rates and endemicity. Conclusions: We hypothesize that malarial infection in the forest follows a pattern where the parasite persists in pockets of holoendemicity, and occupational hazard risk for individuals outside those pockets is associated with behaviors that take place in the proximity of the pockets of endemicity.
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Affiliation(s)
- Alejandro Feged-Rivadeneira
- Department of Anthropology, Stanford University, USA.,School of Political Science, Universidad del Rosario, Colombia
| | - Sian Evans
- DuMond Conservancy, Veterinary Primatology, USA.,Florida International University, Biological Sciences, USA
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Martins-Campos KM, Kuehn A, Almeida A, Duarte APM, Sampaio VS, Rodriguez ÍC, da Silva SGM, Ríos-Velásquez CM, Lima JBP, Pimenta PFP, Bassat Q, Müller I, Lacerda M, Monteiro WM, Barbosa Guerra MDGV. Infection of Anopheles aquasalis from symptomatic and asymptomatic Plasmodium vivax infections in Manaus, western Brazilian Amazon. Parasit Vectors 2018; 11:288. [PMID: 29728152 PMCID: PMC5935932 DOI: 10.1186/s13071-018-2749-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/26/2018] [Indexed: 12/22/2022] Open
Abstract
Background Asymptomatic individuals are one of the major challenges for malaria elimination programs in endemic areas. In the absence of clinical symptoms and with a lower parasite density they constitute silent reservoirs considered important for maintaining transmission of human malaria. Studies from Brazil have shown that infected individuals may carry these parasites for long periods. Results Patients were selected from three periurban endemic areas of the city of Manaus, in the western Brazilian Amazon. Symptomatic and asymptomatic patients with positive thick blood smear and quantitative real-time PCR (qPCR) positive for Plasmodium vivax were invited to participate in the study. A standardised pvs25 gene amplification by qPCR was used for P. vivax gametocytes detection. Anopheles aquasalis were fed using membrane feeding assays (MFA) containing blood from malaria patients. Parasitemia of 42 symptomatic and 25 asymptomatic individuals was determined by microscopic examination of blood smears and qPCR. Parasitemia density and gametocyte density were assessed as determinants of infection rates and oocysts densities. A strong correlation between gametocyte densities (microscopy and molecular techniques) and mosquito infectivity (P < 0.001) and oocysts median numbers (P < 0.05) was found in both groups. The ability to infect mosquitoes was higher in the symptomatic group (41%), but infectivity in the asymptomatic group was also seen (1.42%). Conclusions Although their infectivity to mosquitoes is relatively low, given the high prevalence of P. vivax asymptomatic carriers they are likely to play and important role in malaria transmission in the city of Manaus. The role of asymptomatic infections therefore needs to be considered in future malaria elimination programs in Brazil. Electronic supplementary material The online version of this article (10.1186/s13071-018-2749-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Keillen M Martins-Campos
- Programa de Pós Graduação em Medicina Tropical, Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.,Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Andrea Kuehn
- Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.,ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Anne Almeida
- Programa de Pós Graduação em Medicina Tropical, Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.,Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Ana Paula M Duarte
- Programa de Pós Graduação em Medicina Tropical, Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.,Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | | | - Íria C Rodriguez
- Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Sara G M da Silva
- Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | | | | | - Paulo Filemon Paolucci Pimenta
- Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.,Centro de Pesquisas René Rachou, Fiocruz, Belo Horizonte, Brazil
| | - Quique Bassat
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Ivo Müller
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.,Walter and Eliza Hall Institute, Parkville, Australia
| | - Marcus Lacerda
- Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.,Instituto de Pesquisas Leônidas & Maria Deane, Fiocruz, Manaus, Brazil
| | - Wuelton M Monteiro
- Programa de Pós Graduação em Medicina Tropical, Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.,Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Maria das Graças V Barbosa Guerra
- Programa de Pós Graduação em Medicina Tropical, Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil. .,Departamento de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
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White SE, Harvey SA, Meza G, Llanos A, Guzman M, Gamboa D, Vinetz JM. Acceptability of a herd immunity-focused, transmission-blocking malaria vaccine in malaria-endemic communities in the Peruvian Amazon: an exploratory study. Malar J 2018; 17:179. [PMID: 29703192 PMCID: PMC5921293 DOI: 10.1186/s12936-018-2328-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 04/18/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND A transmission-blocking vaccine (TBV) to prevent malaria-infected humans from infecting mosquitoes has been increasingly considered as a tool for malaria control and elimination. This study tested the hypothesis that a malaria TBV would be acceptable among residents of a malaria-hypoendemic region. METHODS The study was carried out in six Spanish-speaking rural villages in the Department of Loreto in the Peruvian Amazon. These villages comprise a cohort of 430 households associated with the Peru-Brazil International Centre for Excellence in Malaria Research. Individuals from one-third (143) of enrolled households in an ongoing longitudinal, prospective cohort study in 6 communities in Loreto, Peru, were randomly selected to participate by answering a pre-validated questionnaire. RESULTS All 143 participants expressed desire for a malaria vaccine in general; only 1 (0.7%) expressed unwillingness to receive a transmission-blocking malaria vaccine. Injection was considered most acceptable for adults (97.2%); for children drops in the mouth were preferred (96.8%). Acceptability waned marginally with the prospect of multiple injections (83.8%) and different projected efficacies at 70 and 50% (90.1 and 71.8%, respectively). Respondents demonstrated clear understanding that the vaccine was for community, rather than personal, protection against malaria infection. DISCUSSION In this setting of the Peruvian Amazon, a transmission-blocking malaria vaccine was found to be almost universally acceptable. This study is the first to report that residents of a malaria-endemic region have been queried regarding a malaria vaccine strategy that policy-makers in the industrialized world often dismiss as altruistic.
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Affiliation(s)
- Sara E White
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego School of Medicine, 9500 Gilman Drive 0760, Biomedical Research Facility Room 4A16, La Jolla, CA, 92093-0760, USA
| | - Steven A Harvey
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St. E5030, Baltimore, MD, 21205, USA.
| | - Graciela Meza
- Facultad de Medicina Humana, Universidad Nacional de la Amazonia Peruana, Iquitos, Peru
| | - Alejandro Llanos
- Malaria and Leishmaniasis Division, Instituto de Medicina Tropical Alexander von Humboldt, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru
| | - Mitchel Guzman
- Malaria and Leishmaniasis Division, Instituto de Medicina Tropical Alexander von Humboldt, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru
| | - Dionicia Gamboa
- Malaria and Leishmaniasis Division, Instituto de Medicina Tropical Alexander von Humboldt, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru.,Department of Cellular and Molecular Sciences, Faculty of Sciences and Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego School of Medicine, 9500 Gilman Drive 0760, Biomedical Research Facility Room 4A16, La Jolla, CA, 92093-0760, USA. .,Malaria and Leishmaniasis Division, Instituto de Medicina Tropical Alexander von Humboldt, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru. .,Department of Cellular and Molecular Sciences, Faculty of Sciences and Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.
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Micro-epidemiology of mixed-species malaria infections in a rural population living in the Colombian Amazon region. Sci Rep 2018; 8:5543. [PMID: 29615693 PMCID: PMC5883018 DOI: 10.1038/s41598-018-23801-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/21/2018] [Indexed: 12/19/2022] Open
Abstract
Malaria outbreaks have been reported in recent years in the Colombian Amazon region, malaria has been re-emerging in areas where it was previously controlled. Information from malaria transmission networks and knowledge about the population characteristics influencing the dispersal of parasite species is limited. This study aimed to determine the distribution patterns of Plasmodium vivax, P. malariae and P. falciparum single and mixed infections, as well as the significant socio-spatial groupings relating to the appearance of such infections. An active search in 57 localities resulted in 2,106 symptomatic patients being enrolled. Parasitaemia levels were assessed by optical microscopy, and parasites were detected by PCR. The association between mixed infections (in 43.2% of the population) and socio-spatial factors was modelled using logistic regression and multiple correspondence analyses. P. vivax occurred most frequently (71.0%), followed by P. malariae (43.2%), in all localities. The results suggest that a parasite density-dependent regulation model (with fever playing a central role) was appropriate for modelling the frequency of mixed species infections in this population. This study highlights the under-reporting of Plasmodium spp. mixed infections in the malaria-endemic area of the Colombian Amazon region and the association between causative and environmental factors in such areas.
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Almeida ACG, Kuehn A, Castro AJM, Vitor-Silva S, Figueiredo EFG, Brasil LW, Brito MAM, Sampaio VS, Bassat Q, Felger I, Tadei WP, Monteiro WM, Mueller I, Lacerda MVG. High proportions of asymptomatic and submicroscopic Plasmodium vivax infections in a peri-urban area of low transmission in the Brazilian Amazon. Parasit Vectors 2018; 11:194. [PMID: 29558985 PMCID: PMC5859403 DOI: 10.1186/s13071-018-2787-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 03/07/2018] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Population-based studies conducted in Latin America have shown a high proportion of asymptomatic and submicroscopic malarial infections. Considering efforts aiming at regional elimination, it is important to investigate the role of this asymptomatic reservoir in malaria transmission in peri-urban areas. This study aimed to estimate the prevalence of Plasmodium spp. and gametocyte burden on symptomatic and asymptomatic infections in the Brazilian Amazon. RESULTS Two cross-sectional household surveys (CS) were conducted including all inhabitants in a peri-urban area of Manaus, western Amazonas State, Brazil. Malaria parasites were detected by light microscopy (LM) and qPCR. Sexual stages of Plasmodium spp. were detected by LM and RT-qPCR. A total of 4083 participants were enrolled during the two surveys. In CS1, the prevalence of Plasmodium vivax infections was 4.3% (86/2010) by qPCR and 1.6% (32/2010) by LM. Fifty percent (43/86) of P. vivax infected individuals (qPCR) carried P. vivax gametocytes. In CS2, 3.4% (70/2073) of participants had qPCR-detectable P. vivax infections, of which 42.9% (30/70) of infections were gametocyte positive. The P. vivax parasite density was associated with gametocyte carriage (P < 0.001). Sixty-seven percent of P. vivax infected individuals and 53.4% of P. vivax gametocyte carriers were asymptomatic. CONCLUSIONS This study confirms a substantial proportion of asymptomatic and submicroscopic P. vivax infections in the study area. Most asymptomatic individuals carried gametocytes and presented low asexual parasitemia. This reservoir actively contributes to malaria transmission in the Brazilian Amazon, underscoring a need to implement more efficient control and elimination strategies.
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Affiliation(s)
- Anne C G Almeida
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Av. Pedro Teixeira, N.25, Dom Pedro, Manaus, Amazonas, CEP: 69040-000, Brazil. .,Universidade do Estado do Amazonas (UEA), Av. Djalma Batista, N. 3578, Flores, Manaus, Amazonas, CEP: 69005-010, Brazil.
| | - Andrea Kuehn
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Carrer del Rosselló, 132, 08036, Barcelona, Spain
| | - Arthur J M Castro
- Universidade do Estado do Amazonas (UEA), Av. Djalma Batista, N. 3578, Flores, Manaus, Amazonas, CEP: 69005-010, Brazil.,Instituto Nacional de Pesquisas da Amazônia (INPA), Av. André Araújo, N. 2.936, Petrópolis, Manaus, CEP: 69067-375, Brazil
| | - Sheila Vitor-Silva
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Av. Pedro Teixeira, N.25, Dom Pedro, Manaus, Amazonas, CEP: 69040-000, Brazil
| | - Erick F G Figueiredo
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Av. Pedro Teixeira, N.25, Dom Pedro, Manaus, Amazonas, CEP: 69040-000, Brazil
| | - Larissa W Brasil
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Av. Pedro Teixeira, N.25, Dom Pedro, Manaus, Amazonas, CEP: 69040-000, Brazil
| | - Marcelo A M Brito
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Av. Pedro Teixeira, N.25, Dom Pedro, Manaus, Amazonas, CEP: 69040-000, Brazil.,Universidade do Estado do Amazonas (UEA), Av. Djalma Batista, N. 3578, Flores, Manaus, Amazonas, CEP: 69005-010, Brazil
| | - Vanderson S Sampaio
- Fundação de Vigilância em Saúde do Amazonas, Sala de Análise de Situação em Saúde, Av. Torquato Tapajós, N. 6132, Colônia Santo Antonio, Manaus, CEP:69093-018, Brazil
| | - Quique Bassat
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Carrer del Rosselló, 132, 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23 08010, Barcelona, Spain
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Wanderli P Tadei
- Instituto Nacional de Pesquisas da Amazônia (INPA), Av. André Araújo, N. 2.936, Petrópolis, Manaus, CEP: 69067-375, Brazil
| | - Wuelton M Monteiro
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Av. Pedro Teixeira, N.25, Dom Pedro, Manaus, Amazonas, CEP: 69040-000, Brazil. .,Universidade do Estado do Amazonas (UEA), Av. Djalma Batista, N. 3578, Flores, Manaus, Amazonas, CEP: 69005-010, Brazil.
| | - Ivo Mueller
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Carrer del Rosselló, 132, 08036, Barcelona, Spain.,Walter and Eliza Hall Institute, Parkville, Australia
| | - Marcus V G Lacerda
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Av. Pedro Teixeira, N.25, Dom Pedro, Manaus, Amazonas, CEP: 69040-000, Brazil.,Universidade do Estado do Amazonas (UEA), Av. Djalma Batista, N. 3578, Flores, Manaus, Amazonas, CEP: 69005-010, Brazil.,Instituto de Pesquisas Leônidas e Maria Deane (ILMD), Manaus, Brazil
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Martin TCS, Vinetz JM. Asymptomatic Plasmodium vivax parasitaemia in the low-transmission setting: the role for a population-based transmission-blocking vaccine for malaria elimination. Malar J 2018; 17:89. [PMID: 29466991 PMCID: PMC5822557 DOI: 10.1186/s12936-018-2243-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 02/17/2018] [Indexed: 12/21/2022] Open
Abstract
Plasmodium vivax remains an important cause of morbidity and mortality across the Americas, Horn of Africa, East and South East Asia. Control of transmission has been hampered by emergence of chloroquine resistance and several intrinsic characteristics of infection including asymptomatic carriage, challenges with diagnosis, difficulty eradicating the carrier state and early gametocyte appearance. Complex human-parasite-vector immunological interactions may facilitate onward infection of mosquitoes. Given these challenges, new therapies are being explored including the development of transmission to mosquito blocking vaccines. Herein, the case supporting the need for transmission-blocking vaccines to augment control of P. vivax parasite transmission and explore factors that are limiting eradication efforts is discussed.
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Affiliation(s)
- Thomas C S Martin
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, CA, USA.
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Neves PA, Colabuono FI, Ferreira PAL, Kawakami SK, Taniguchi S, Figueira RCL, Mahiques MM, Montone RC, Bícego MC. Depositional history of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in an Amazon estuary during the last century. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 615:1262-1270. [PMID: 29751431 DOI: 10.1016/j.scitotenv.2017.09.303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/27/2017] [Accepted: 09/27/2017] [Indexed: 06/08/2023]
Abstract
The sources and depositional history of OCPs (organochlorine pesticides), PCBs (polychlorinated biphenyls) and PAHs (polycyclic aromatic hydrocarbons) over the last 100years were determined in two sediment cores collected in the Amazon region. It was possible to distinguish two depositional periods along the cores. The first period occurred before extensive anthropogenic effects were registered in the sediments. During this time interval, the concentrations of all OCPs and PCBs were below the detection limits (DL), and the PAH concentrations were low and essentially constant (58.19-124.28ngg-1). The second period starts in the mid-1960s and reflects the increased human influence in the area. The concentrations of OCPs, PCBs, and PAHs increased towards the top of the cores, varying between <DL to 72.67ngg-1, <DL to 0.87ngg-1 and 331 to 2341ngg-1, respectively. In general, OCP results showed trends corresponding to the production, usage and prohibition periods of POPs in Brazil. Compounds related to wood treatment, such HCHs and chlordanes, were predominant among the OCPs, which may be associated with many sawmills located in this region. The increase in PAH concentration after the 1960s is mainly due to forest fires, caused by the implementation of large-scale cattle ranches, which burned forests to create pastures. The background PAH concentrations before the 1960s are probably related to natural diagenetic processes.
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Affiliation(s)
- Patrícia A Neves
- Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, Praça do Oceanográfico 191, São Paulo, SP 05508-120, Brazil.
| | - Fernanda I Colabuono
- Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, Praça do Oceanográfico 191, São Paulo, SP 05508-120, Brazil
| | - Paulo A L Ferreira
- Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, Praça do Oceanográfico 191, São Paulo, SP 05508-120, Brazil
| | - Silvia K Kawakami
- Universidade Federal do Pará, Instituto de Geociências, Faculdade de Oceanografia, Av Augusto Corrêa 1, Campus do Guamá, Belém, PA 66075-110, Brazil
| | - Satie Taniguchi
- Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, Praça do Oceanográfico 191, São Paulo, SP 05508-120, Brazil
| | - Rubens C L Figueira
- Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, Praça do Oceanográfico 191, São Paulo, SP 05508-120, Brazil
| | - Michel M Mahiques
- Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, Praça do Oceanográfico 191, São Paulo, SP 05508-120, Brazil; Universidade de São Paulo, Instituto de Energia e Ambiente, Av. Prof. Luciano Gualberto, 1289, São Paulo, SP 05508-900, Brazil
| | - Rosalinda C Montone
- Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, Praça do Oceanográfico 191, São Paulo, SP 05508-120, Brazil
| | - Márcia C Bícego
- Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, Praça do Oceanográfico 191, São Paulo, SP 05508-120, Brazil
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Atelu GR, Duah NO, Wilson MD. Carriage of sub-microscopic sexual and asexual Plasmodium falciparum stages in the dry season at Navrongo, Ghana. Ghana Med J 2018; 50:220-227. [PMID: 28579627 DOI: 10.4314/gmj.v50i4.4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND We investigated the prevalence of sub-microscopic Plasmodium falciparum infections and gametocyte carriage in asymptomatic individuals in Navrongo in northern Ghana, an area of seasonal malaria transmission. DESIGN A cross sectional study of 209 randomly selected participants of all age-groups was conducted in February and March, 2015. METHODS Capillary blood samples collected from these individuals were used for the detection of both asexual and gametocyte stage parasites by microscopy, reverse transcriptase polymerase chain reaction (RT-PCR) and conventional nested PCR methods. The prevalence data as determined by microscopy and molecular methods were compared using chi-square tests. RESULTS Parasitaemia from these asymptomatic infections ranged from 40 to 3,520 parasites/µl of blood (geometric mean parasitaemia = 732 parasites/µl). The prevalence of asymptomatic P. falciparum carriage was 4.8% (10/209) and 13.9% (29/209) using microscopy and RT-PCR respectively. The overall prevalence of sub-microscopic infections in the total number of samples analysed was 9.1% (19/209) and 66% (19/29) of the asymptomatic infections. P. falciparum gametocytemia detected by microscopy was 1% (2/209) and 3.8% (8/209) by PCR. CONCLUSION This is the first report of sub-microscopic asexual and gametocytes infections in the dry season in a seasonal malaria transmission area in Ghana. It has established that persistent latent malaria infections occur and that these could supply the source of parasites for the next transmission season. The findings highlight the presence of sub-microscopic infections and therefore the need for active case detection surveillance to eliminate "asymptomatic reservoir" parasites and consequently break the transmission of the disease in Ghana. FUNDING Bill and Melinda Gates Foundation grant awarded to Noguchi Memorial Institute for Medical Research Postdoctoral and Postgraduate Training in Infectious Diseases Research (Global Health Grant # OPP52155); National Institutes of Health grant (NIH-NIAID RO1 # 1RO1AI099623) to MDW; European Developing Countries Clinical Trials Partnership (EDCTP)-West African Network of Excellence for Clinical Trials in TB, AIDS and Malaria (WANETAM) (Project code CB.07.41700.007).
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Affiliation(s)
- Geoffrey R Atelu
- Ghana Field Epidemiology and Laboratory Training Program, School of Public Health, College of Health Sciences, University of Ghana, Legon, Ghana.,Ghana Health Service, Accra, Ghana
| | - Nancy O Duah
- Epidemiology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, P. O. Box LG 581, Legon, Ghana
| | - Michael D Wilson
- Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, P. O. Box LG 581, Legon, Ghana
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Cabral FJ, Vianna LG, Medeiros MM, Carlos BC, Martha RD, Silva NM, Silva LHPD, Stabeli RG, Wunderlich G. Immunoproteomics of Plasmodium falciparum-infected red blood cell membrane fractions. Mem Inst Oswaldo Cruz 2017; 112:850-856. [PMID: 29211247 PMCID: PMC5719555 DOI: 10.1590/0074-02760170041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 06/30/2017] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND The surface of infected red blood cells (iRBCs) has been widely investigated
because of the molecular complexity and pathogenesis mechanisms involved.
Asymptomatic individuals are important in the field because they can
perpetuate transmission as natural reservoirs and present a challenge for
diagnosing malaria because of their low levels of circulating parasites.
Recent studies of iRBC antibody recognition have shown that responses are
quantitatively similar in symptomatic and asymptomatic infections, but no
studies have characterised the plasmodial proteins targeted by this
response. OBJECTIVES Our main objective was to identify Plasmodium falciparum
proteins associated with iRBC ghosts recognised by antibodies in the sera of
symptomatic and asymptomatic individuals in the Brazilian Amazon. METHODS We collected symptomatic and asymptomatic sera from patients residing in the
Brazilian Amazon and P. falciparum iRBC ghosts to identify
the proteins involved in natural antibody recognition by 2D-electrophoresis,
western blotting, and high- resolution mass spectrometry. FINDINGS 2D gel-based immunoproteome analysis using symptomatic and asymptomatic sera
identified 11 proteins with at least one unique peptide, such as chaperones
HSP70-1 and HSP70-x, which likely are components of the secretion
machinery/PTEX translocon. PfEMP1 is involved in antigenic variation in
symptomatic infections and we found putative membrane proteins whose
functions are unknown. MAIN FINDINGS Our results suggest a potential role of old and new proteins, such as
antigenic variation proteins, iRBC remodelling, and membrane proteins, with
no assigned functions related to the immune response against P.
falciparum, providing insights into the pathogenesis,
erythrocyte remodelling, and secretion machinery important for alternative
diagnosis and/or malaria therapy.
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Affiliation(s)
- Fernanda J Cabral
- Universidade Estadual de Campinas, Instituto de Biologia, Departamento de Biologia Animal, Campinas, SP, Brasil.,Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil
| | | | - Marcia M Medeiros
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil.,Universidade Nova de Lisboa, Instituto de Higiene e Medicina Tropical, Lisboa, Portugal
| | - Bianca Cechetto Carlos
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil
| | | | - Nadia Maria Silva
- Universidade Estadual de Campinas, Instituto de Biologia, Departamento de Biologia Animal, Campinas, SP, Brasil
| | | | | | - Gerhard Wunderlich
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Parasitologia, São Paulo, SP, Brasil
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Carrasco-Escobar G, Miranda-Alban J, Fernandez-Miñope C, Brouwer KC, Torres K, Calderon M, Gamboa D, Llanos-Cuentas A, Vinetz JM. High prevalence of very-low Plasmodium falciparum and Plasmodium vivax parasitaemia carriers in the Peruvian Amazon: insights into local and occupational mobility-related transmission. Malar J 2017; 16:415. [PMID: 29037202 PMCID: PMC5644076 DOI: 10.1186/s12936-017-2063-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/11/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The incidence of malaria due both to Plasmodium falciparum and Plasmodium vivax in the Peruvian Amazon has risen in the past 5 years. This study tested the hypothesis that the maintenance and emergence of malaria in hypoendemic regions such as Amazonia is determined by submicroscopic and asymptomatic Plasmodium parasitaemia carriers. The present study aimed to precisely quantify the rate of very-low parasitaemia carriers in two sites of the Peruvian Amazon in relation to transmission patterns of P. vivax and P. falciparum in this area. METHODS This study was carried out within the Amazonian-ICEMR longitudinal cohort. Blood samples were collected for light microscopy diagnosis and packed red blood cell (PRBC) samples were analysed by qPCR. Plasma samples were tested for total IgG reactivity against recombinant PvMSP-10 and PfMSP-10 antigens by ELISA. Occupation and age 10 years and greater were considered surrogates of occupation-related mobility. Risk factors for P. falciparum and P. vivax infections detected by PRBC-qPCR were assessed by multilevel logistic regression models. RESULTS Among 450 subjects, the prevalence of P. vivax by PRBC-PCR (25.1%) was sixfold higher than that determined by microscopy (3.6%). The prevalence of P. falciparum infection was 4.9% by PRBC-PCR and 0.2% by microscopy. More than 40% of infections had parasitaemia under 5 parasites/μL. Multivariate analysis for infections detected by PRBC-PCR showed that participants with recent settlement in the study area (AOR 2.1; 95% CI 1.03:4.2), age ≥ 30 years (AOR 3.3; 95% CI 1.6:6.9) and seropositivity to P. vivax (AOR 1.8; 95% CI 1.0:3.2) had significantly higher likelihood of P. vivax infection, while the odds of P. falciparum infection was higher for participants between 10 and 29 years (AOR 10.7; 95% CI 1.3:91.1) and with a previous P. falciparum infection (AOR 10.4; 95% CI 1.5:71.1). CONCLUSIONS This study confirms the contrasting transmission patterns of P. vivax and P. falciparum in the Peruvian Amazon, with stable local transmission for P. vivax and the source of P. falciparum to the study villages dominated by very low parasitaemia carriers, age 10 years and older, who had travelled away from home for work and brought P. falciparum infection with them.
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Affiliation(s)
- Gabriel Carrasco-Escobar
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru. .,Facultad de Salud Pública, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Julio Miranda-Alban
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Carlos Fernandez-Miñope
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Kimberly C Brouwer
- Division of Epidemiology, Department of Family Medicine & Public Health, University of California, San Diego, La Jolla, CA, USA
| | - Katherine Torres
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru.,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Maritza Calderon
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Dionicia Gamboa
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru.,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru.,Instituto de Medicinal Tropical "Alexander von Humboldt", Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Alejandro Llanos-Cuentas
- Facultad de Salud Pública, Universidad Peruana Cayetano Heredia, Lima, Peru.,Instituto de Medicinal Tropical "Alexander von Humboldt", Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M Vinetz
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru. .,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru. .,Instituto de Medicinal Tropical "Alexander von Humboldt", Universidad Peruana Cayetano Heredia, Lima, Peru. .,Division of Infectious Diseases, Department of Medicine, University of California, San Diego, 9500 Gilman Drive MC0760, Biomedical Research Facility-2, Room 4A16, La Jolla, CA, USA.
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Lana RM, Riback TIS, Lima TFM, da Silva-Nunes M, Cruz OG, Oliveira FGS, Moresco GG, Honório NA, Codeço CT. Socioeconomic and demographic characterization of an endemic malaria region in Brazil by multiple correspondence analysis. Malar J 2017; 16:397. [PMID: 28969634 PMCID: PMC5625626 DOI: 10.1186/s12936-017-2045-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 09/23/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the process of geographical retraction of malaria, some important endemicity pockets remain. Here, we report results from a study developed to obtain detailed community data from an important malaria hotspot in Latin America (Alto Juruá, Acre, Brazil), to investigate the association of malaria with socioeconomic, demographic and living conditions. METHODS A household survey was conducted in 40 localities (n = 520) of Mâncio Lima and Rodrigues Alves municipalities, Acre state. Information on previous malaria, schooling, age, gender, income, occupation, household structure, habits and behaviors related to malaria exposure was collected. Multiple correspondence analysis (MCA) was applied to characterize similarities between households and identify gradients. The association of these gradients with malaria was assessed using regression. RESULTS The first three dimensions of MCA accounted for almost 50% of the variability between households. The first dimension defined an urban/rurality gradient, where urbanization was associated with the presence of roads, basic services as garbage collection, water treatment, power grid energy, and less contact with the forest. There is a significant association between this axis and the probability of malaria at the household level, OR = 1.92 (1.23-3.02). The second dimension described a gradient from rural settlements in agricultural areas to those in forested areas. Access via dirt road or river, access to electricity power-grid services and aquaculture were important variables. Malaria was at lower risk at the forested area, OR = 0.55 (1.23-1.12). The third axis detected intraurban differences and did not correlate with malaria. CONCLUSIONS Living conditions in the study area are strongly geographically structured. Although malaria is found throughout all the landscapes, household traits can explain part of the variation found in the odds of having malaria. It is expected these results stimulate further discussions on modelling approaches targeting a more systemic and multi-level view of malaria dynamics.
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Affiliation(s)
- Raquel M Lana
- Programa de Pós-Graduação em Epidemilogia em Saúde Pública, Escola Nacional de Saúde Pública Sérgio Arouca, Fundação Oswaldo Cruz, Rua Leopoldo Bulhões, 1480, Manguinhos, Rio de Janeiro, RJ, 21041-210, Brazil. .,Programa de Computação Científica, Fundação Oswaldo Cruz, Residência Oficial, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil.
| | - Thais I S Riback
- Programa de Computação Científica, Fundação Oswaldo Cruz, Residência Oficial, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil
| | - Tiago F M Lima
- Laboratório de Engenharia e Desenvolvimento de Sistemas, Departamento de Computação e Sistemas, Instituto de Ciências Exatas e Aplicadas, Universidade Federal de Ouro Preto., Rua 36, n. 115, Loanda, João Monlevade, MG, 35931-008, Brazil
| | - Mônica da Silva-Nunes
- Centro de Ciências da Saúde, Universidade Federal do Acre, Campus Universitário-BR 364, km 4-Distrito Industrial, Rio Branco, AC, 69920-900, Brazil
| | - Oswaldo G Cruz
- Programa de Computação Científica, Fundação Oswaldo Cruz, Residência Oficial, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil
| | - Francisco G S Oliveira
- Campus Cruzeiro do Sul, Universidade Federal do Acre, Estrada do Canela Fina, s/n, Cruzeiro do Sul, AC, 69980-000, Brazil
| | - Gilberto G Moresco
- Coordenação Geral dos Programas Nacionais de Controle e Prevenção da Malária e das Doenças transmitidas pelo Aedes, Departamento de Vigilância das Doenças Transmissíveis, Secretaria de Vigilância em Saúde-Ministério da Saúde, SRTV 702, Via W 5 Norte, Ed. PO700-6 andar, Brasília, DF, 70723-040, Brazil
| | - Nildimar A Honório
- Laboratório de Mosquitos Transmissores de Hematozoários-Lathema, Instituto Oswaldo Cruz, FIOCRUZ, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil.,Núcleo Operacional Sentinela de Mosquitos Vetores-Nosmove/FIOCRUZ, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil
| | - Cláudia T Codeço
- Programa de Computação Científica, Fundação Oswaldo Cruz, Residência Oficial, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil
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Rosas-Aguirre A, Guzman-Guzman M, Gamboa D, Chuquiyauri R, Ramirez R, Manrique P, Carrasco-Escobar G, Puemape C, Llanos-Cuentas A, Vinetz JM. Micro-heterogeneity of malaria transmission in the Peruvian Amazon: a baseline assessment underlying a population-based cohort study. Malar J 2017; 16:312. [PMID: 28778210 PMCID: PMC5544973 DOI: 10.1186/s12936-017-1957-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 07/28/2017] [Indexed: 11/10/2022] Open
Abstract
Background Understanding the dynamics of malaria transmission in diverse endemic settings is key for designing and implementing locally adapted and sustainable control and elimination strategies. A parasitological and epidemiological survey was conducted in September–October 2012, as a baseline underlying a 3-year population-based longitudinal cohort study. The aim was to characterize malaria transmission patterns in two contrasting ecological rural sites in the Peruvian Amazon, Lupuna (LUP), a riverine environment, and Cahuide (CAH), associated with road-linked deforestation. Methods After a full population census, 1941 individuals 3 years and older (829 in LUP, 1112 in CAH) were interviewed, clinically examined and had a blood sample taken for the detection of malaria parasites by microscopy and PCR. Species-specific parasite prevalence was estimated overall and by site. Multivariate logistic regression models assessed risk factors for parasite infection by PCR, while SaTScan detected spatial clusters of PCR-positive individuals within each site. In addition, data from routine malaria surveillance in the period 2009–2012 were obtained. Results Parasite prevalence by PCR was higher in CAH than in LUP for Plasmodium vivax (6.2% vs. 3.9%) and for Plasmodium falciparum (2.6% vs. 1.2%). Among PCR-confirmed infections, asymptomatic (Asy) parasite carriers were always more common than symptomatic (Sy) infections for P. vivax (Asy/Sy ratio: 2/1 in LUP and 3.7/1 in CAH) and for P. falciparum (Asy/Sy ratio: 1.3/1 in LUP and 4/1 in CAH). Sub-patent (Spat) infections also predominated over patent (Pat) infections for both species: P. vivax (Spat/Pat ratio: 2.8/1 in LUP and 3.7/1 in CAH) and P. falciparum malaria (Spat/Pat ratio: 1.9/1 in LUP and 26/0 in CAH). For CAH, age, gender and living in a household without electricity were significantly associated with P. vivax infection, while only age and living in a household with electricity was associated with P. falciparum infection. For LUP, only household overcrowding was associated with P. falciparum infection. The spatial analysis only identified well-defined clusters of P. vivax and P. falciparum infected individuals in CAH. Reported malaria incidence indicated that malaria transmission has long occurred in LUP with primarily seasonal patterns, and confirmed a malaria outbreak in CAH since May 2012. Conclusions This parasitological and epidemiological baseline assessment demonstrates that malaria transmission and parasite prevalence is heterogeneous in the Peruvian Amazon, and influenced by local socio-demographics and ecological contexts. Riverine and road construction/deforestation contexts must be taken into account in order to carry out effective anti-malaria control and elimination efforts. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1957-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Angel Rosas-Aguirre
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima 31, Peru.,Research Institute of Health and Society (IRSS), Université Catholique de Louvain, 1200, Brussels, Belgium
| | - Mitchel Guzman-Guzman
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru
| | - Dionicia Gamboa
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima 31, Peru.,Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru.,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru
| | - Raul Chuquiyauri
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima 31, Peru.,Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, 9500 Gilman Drive MC0760, Biomedical Research Facility-2, Room 4A16, La Jolla, California, CA, 92093, USA
| | - Roberson Ramirez
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru
| | - Paulo Manrique
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru
| | - Gabriel Carrasco-Escobar
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru.,Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima 31, Peru
| | - Carmen Puemape
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima 31, Peru.,Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima 31, Peru
| | - Joseph M Vinetz
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima 31, Peru. .,Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru. .,Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Peru. .,Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, 9500 Gilman Drive MC0760, Biomedical Research Facility-2, Room 4A16, La Jolla, California, CA, 92093, USA.
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Sáenz FE, Arévalo-Cortés A, Valenzuela G, Vallejo AF, Castellanos A, Poveda-Loayza AC, Gutierrez JB, Alvarez A, Yan YH, Benavides Y, Castro LE, Arévalo-Herrera M, Herrera S. Malaria epidemiology in low-endemicity areas of the northern coast of Ecuador: high prevalence of asymptomatic infections. Malar J 2017; 16:300. [PMID: 28747199 PMCID: PMC5530496 DOI: 10.1186/s12936-017-1947-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 07/18/2017] [Indexed: 11/25/2022] Open
Abstract
Background The recent scale-up in malaria control measures in Latin America has resulted in a significant decrease in the number of reported cases in several countries including Ecuador, where it presented a low malaria incidence in recent years (558 reported cases in 2015) with occasional outbreaks of both Plasmodium falciparum and Plasmodium vivax in the coastal and Amazonian regions. This success in malaria control in recent years has led Ecuador to transition its malaria policy from control to elimination. Results This study evaluated the general knowledge, attitude and practices (KAP) about malaria, as well as its prevalence in four communities of an endemic area in northwest Ecuador. A total of 258 interviews to assess KAP in the community indicated that most people in the study area have a basic knowledge about the disease but did not use to contribute to its control. Six hundred and forty-eight blood samples were collected and analysed by thick blood smear and real-time PCR. In addition, the distribution of the infections was mapped in the study communities. Although, no parasites were found by microscopy, by PCR the total malaria prevalence was 7.5% (6.9% P. vivax and 0.6% P. falciparum), much higher than expected and comparable to that reported in endemic areas of neighbouring countries with higher malaria transmission. Serology using ELISA and immunofluorescence indicated 27% respondents for P. vivax and 22% respondents for P. falciparum. Conclusions Results suggest that despite a great malaria reduction in Ecuador, transition from control to elimination would demand further improvement in malaria diagnostics, including active case detection to identify and treat parasite asymptomatic carriers, as well as community participation in its elimination.
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Affiliation(s)
- Fabián E Sáenz
- Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Calle Pambacienda y San Pedro del Valle, Quito, Ecuador.
| | - Andrea Arévalo-Cortés
- Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Calle Pambacienda y San Pedro del Valle, Quito, Ecuador
| | - Gabriela Valenzuela
- Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Calle Pambacienda y San Pedro del Valle, Quito, Ecuador
| | | | | | - Andrea C Poveda-Loayza
- Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Calle Pambacienda y San Pedro del Valle, Quito, Ecuador
| | - Juan B Gutierrez
- Department of Mathematics, Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Alvaro Alvarez
- Malaria Vaccine and Drug Development Center, Cali, Colombia
| | - Yi Heng Yan
- Department of Mathematics, Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | | | | | - Myriam Arévalo-Herrera
- Caucaseco Scientific Research Center, Cali, Colombia.,School of Health, Universidad del Valle, Cali, Colombia
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Recht J, Siqueira AM, Monteiro WM, Herrera SM, Herrera S, Lacerda MVG. Malaria in Brazil, Colombia, Peru and Venezuela: current challenges in malaria control and elimination. Malar J 2017; 16:273. [PMID: 28676055 PMCID: PMC5496604 DOI: 10.1186/s12936-017-1925-6] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 06/29/2017] [Indexed: 01/24/2023] Open
Abstract
In spite of significant progress towards malaria control and elimination achieved in South America in the 2000s, this mosquito-transmitted tropical disease remains an important public health concern in the region. Most malaria cases in South America come from Amazon rain forest areas in northern countries, where more than half of malaria is caused by Plasmodium vivax, while Plasmodium falciparum malaria incidence has decreased in recent years. This review discusses current malaria data, policies and challenges in four South American Amazon countries: Brazil, Colombia, Peru and the Bolivarian Republic of Venezuela. Challenges to continuing efforts to further decrease malaria incidence in this region include: a significant increase in malaria cases in recent years in Venezuela, evidence of submicroscopic and asymptomatic infections, peri-urban malaria, gold mining-related malaria, malaria in pregnancy, glucose-6-phosphate dehydrogenase (G6PD) deficiency and primaquine use, and possible under-detection of Plasmodium malariae. Some of these challenges underscore the need to implement appropriate tools and procedures in specific regions, such as a field-compatible molecular malaria test, a P. malariae-specific test, malaria diagnosis and appropriate treatment as part of regular antenatal care visits, G6PD test before primaquine administration for P. vivax cases (with weekly primaquine regimen for G6PD deficient individuals), single low dose of primaquine for P. falciparum malaria in Colombia, and national and regional efforts to contain malaria spread in Venezuela urgently needed especially in mining areas. Joint efforts and commitment towards malaria control and elimination should be strategized based on examples of successful regional malaria fighting initiatives, such as PAMAFRO and RAVREDA/AMI.
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Affiliation(s)
| | - André M Siqueira
- Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil
| | - Wuelton M Monteiro
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil
| | - Sonia M Herrera
- Centro de Investigación Científica Caucaseco, Cali, Colombia
| | | | - Marcus V G Lacerda
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil.,Fiocruz/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado/Institute Elimina, Manaus, Brazil
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Defining micro-epidemiology for malaria elimination: systematic review and meta-analysis. Malar J 2017; 16:164. [PMID: 28427389 PMCID: PMC5399382 DOI: 10.1186/s12936-017-1792-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/28/2017] [Indexed: 11/24/2022] Open
Abstract
Background Malaria risk can vary markedly between households in the same village, or between villages, but the determinants of this “micro-epidemiological” variation in malaria risk remain poorly understood. This study aimed to identify factors that explain fine-scale variation in malaria risk across settings and improve definitions and methods for malaria micro-epidemiology. Methods A systematic review of studies that examined risk factors for variation in malaria infection between individuals, households, clusters, hotspots, or villages in any malaria-endemic setting was conducted. Four databases were searched for studies published up until 6th October 2015. Crude and adjusted effect estimates for risk factors for malaria infection were combined in random effects meta-analyses. Bias was assessed using the Newcastle–Ottawa Quality Assessment Scale. Results From 743 retrieved records, 51 studies were selected, representing populations comprising over 160,000 individuals in 21 countries, in high- and low-endemicity settings. Sixty-five risk factors were identified and meta-analyses were conducted for 11 risk factors. Most studies focused on environmental factors, especially increasing distance from a breeding site (OR 0.89, 95% CI 0.86–0.92, 10 studies). Individual bed net use was protective (OR 0.63, 95% CI 0.52–0.77, 12 studies), but not household bed net ownership. Increasing household size (OR 1.08, 95% CI 1.01–1.15, 4 studies) and household crowding (OR 1.79, 95% CI 1.48–2.16, 4 studies) were associated with malaria infection. Health seeking behaviour, medical history and genetic traits were less frequently studied. Only six studies examined whether individual-level risk factors explained differences in malaria risk at village or hotspot level, and five studies reported different risk factors at different levels of analysis. The risk of bias varied from low to high in individual studies. Insufficient reporting and comparability of measurements limited the number of meta-analyses conducted. Conclusions Several variables associated with individual-level malaria infection were identified, but there was limited evidence that these factors explain variation in malaria risk at village or hotspot level. Social, population and other factors may confound estimates of environmental risk factors, yet these variables are not included in many studies. A structured framework of malaria risk factors is proposed to improve study design and quality of evidence in future micro-epidemiological studies. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1792-1) contains supplementary material, which is available to authorized users.
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Soto-Calle V, Rosas-Aguirre A, Llanos-Cuentas A, Abatih E, DeDeken R, Rodriguez H, Rosanas-Urgell A, Gamboa D, D´Alessandro U, Erhart A, Speybroeck N. Spatio-temporal analysis of malaria incidence in the Peruvian Amazon Region between 2002 and 2013. Sci Rep 2017; 7:40350. [PMID: 28091560 PMCID: PMC5238441 DOI: 10.1038/srep40350] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 12/06/2016] [Indexed: 01/04/2023] Open
Abstract
Malaria remains a major public health problem in the Peruvian Amazon where the persistence of high-risk transmission areas (hotspots) challenges the current malaria control strategies. This study aimed at identifying significant space-time clusters of malaria incidence in Loreto region 2002-2013 and to determine significant changes across years in relation to the control measures applied. Poisson regression and purely temporal, spatial, and space-time analyses were conducted. Three significantly different periods in terms of annual incidence rates (AIR) were identified, overlapping respectively with the pre-, during, and post- implementation control activities supported by PAMAFRO project. The most likely space-time clusters of malaria incidence for P. vivax and P. falciparum corresponded to the pre- and first two years of the PAMAFRO project and were situated in the northern districts of Loreto, while secondary clusters were identified in eastern and southern districts with the latest onset and the shortest duration of PAMAFRO interventions. Malaria in Loreto was highly heterogeneous at geographical level and over time. Importantly, the excellent achievements obtained during 5 years of intensified control efforts totally vanished in only 2 to 3 years after the end of the program, calling for sustained political and financial commitment for the success of malaria elimination as ultimate goal.
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Affiliation(s)
- Veronica Soto-Calle
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima 31, Perú
| | - Angel Rosas-Aguirre
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima 31, Perú
- Research Institute of Health and Society (IRSS), Université catholique de Louvain, Brussels 1200, Belgium
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima 31, Perú
| | - Emmanuel Abatih
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp 2000, Belgium
| | - Redgi DeDeken
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp 2000, Belgium
| | - Hugo Rodriguez
- Dirección Regional de Salud Loreto DIRESA Loreto, Loreto 160, Perú
| | - Anna Rosanas-Urgell
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp 2000, Belgium
| | - Dionicia Gamboa
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima 31, Perú
| | - Umberto D´Alessandro
- Disease Control and Elimination, Medical Research Council Unit, Fajara 220, The Gambia
- London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
- Department of Public Health, Institute of Tropical Medicine, Antwerp 2000, Belgium
| | - Annette Erhart
- Disease Control and Elimination, Medical Research Council Unit, Fajara 220, The Gambia
- Department of Public Health, Institute of Tropical Medicine, Antwerp 2000, Belgium
| | - Niko Speybroeck
- Research Institute of Health and Society (IRSS), Université catholique de Louvain, Brussels 1200, Belgium
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Nascimento JAAD, Guimarães LM, Carvalho-Costa FA. Malaria epidemiology in the State of Piauí, Northeastern Brazil: a retrospective study with secondary data. Rev Soc Bras Med Trop 2017; 49:99-103. [PMID: 27163571 DOI: 10.1590/0037-8682-0153-2015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 09/22/2015] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED INTRODUCTION Malaria is not considered endemic in State of Piauí. METHODS Malaria epidemiology was examined using surveillance data. RESULTS During 2002-2013, of the 484 cases of malaria, 217 were classified as probably acquired in Piauí, most frequently in the Campo Largo, Buriti dos Lopes, and Luzilândia municipalities, and 267 were considered probably imported, from the States of Pará, Maranhão, Amazonas, Roraima, and Rondônia. Probably-imported cases occurred throughout the year, while 80.2% of the probably-acquired cases occurred in April-August, peaking at the end of the rainy season. CONCLUSIONS Malaria surveillance should be intensified. Further ecoepidemiological and entomological studies are needed.
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Affiliation(s)
- Joyce Anny Alves do Nascimento
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucas Melo Guimarães
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Filipe Anibal Carvalho-Costa
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
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Valero-Bernal MV, Tanner M, Muñoz-Navarro S, Valero-Bernal JF. Proportion of fever attributable to malaria in Colombia: Potential indicators for monitoring progress towards malaria elimination. Rev Salud Publica (Bogota) 2017; 19:45-51. [PMID: 30137154 DOI: 10.15446/rsap.v19n1.55933] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 12/08/2016] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE Identify and characterize indicators to assess progress in terms of control and monitoring of malaria in endemic areas of Colombia and compare malaria elimination findings with those of countries in the same region. METHODS Cross-sectional surveys were carried out in 2011 and 2014 in malaria endemic areas in Colombia, Pacific and Caribbean regions. A socio-demographic and a clinical questionnaire were applied to each participant; likewise, written and informed consents were obtained. Capillary blood samples were taken and examined through microscopic tests and rapid diagnostic test. A narrative systematic review was conducted to correlate malaria elimination in Colombia and in countries of the Amazon Region. RESULTS The sample consisted of 548 participants from the departments of Córdoba and Nariño, Colombia. The proportion of positive malaria cases was 3 % (17/548), in which the prevalence of malaria mixed infections was 47 % (8/17). Regarding fever, temperature over 38.0o C, its prevalence was 2.7 % (15/548). Only two febrile patients tested positive for the disease. Prevalence of asymptomatic malaria cases among all positive cases was 88 %. CONCLUSION Asymptomatic malaria cases, mixed infections and self-medication are the challenges that malaria control and elimination programs face. It is important to note that studies on subclinical malaria in the region are scarce. Endemic areas with dense populations and experiencing an increase in immigration levels are more vulnerable to malaria reemergence. Imported malaria cases impact the basic reproduction rate (Ro). Funding resources availability has impact on the sustainability of public health actions and the elimination of malaria in South America.
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Affiliation(s)
- María V Valero-Bernal
- Ph. D. Epidemiology and Dr. Public Health. Faculty of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia.
| | - Marcel Tanner
- MD. Ph. D. Epidemiology. Dhc. Director-Emeritus, Swiss Tropical and Public Health Institute, University of Basel. President, Academia of Sciences. Basel, Switzerland.
| | - Sergio Muñoz-Navarro
- Biostatistician. Ph. D. Biostatistics. Director, School of Public Health. Faculty of Medicine, Universidad de La Frontera. Temuco, Chile.
| | - José F Valero-Bernal
- MD. Anesthesiologist. Surgery Department Anesthesiology Unit, Faculty of Medicine, Universidad Nacional de Colombia. Bogotá, Colombia.
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