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Amoah LE, Cheng NI, Acquah FK, Adu-Amankwah S, Bredu DG, Mensah BA, Anang SF, Abban BC, Busayomi A, Kwarpong SS, Tey PK, Cudjoe E, Asamoah A, Holden TM, Gerardin J, Nonvignon J, Ahorlu C. Diagnostic performance of an ultra-sensitive RDT and a conventional RDT in malaria mass testing, treatment and tracking interventions in southern Ghana. Parasit Vectors 2024; 17:280. [PMID: 38951912 PMCID: PMC11218287 DOI: 10.1186/s13071-024-06354-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 06/15/2024] [Indexed: 07/03/2024] Open
Abstract
BACKGROUND Application of numerous malaria control interventions has led to reduction in clinical malaria cases and deaths but also the realisation that asymptomatic parasite carriers play a key role in sustaining transmission. This study assessed the effectiveness of using the Ultra-sensitive NxTek eliminate RDT (uRDT) and conventional SD Bioline HRP2 RDT (cRDT) in diagnosing asymptomatic parasitaemia while measuring the impact of mass testing, treatment and tracking (MTTT) on the prevalence of asymptomatic malaria over a 1-year period in Ghana. METHODS A total of 4000 targeted participants from two towns, Obom and Kofi Kwei, with their surrounding villages, were tested for asymptomatic malaria four times over the study period using uRDT (intervention) and the cRDT (control) respectively. Participants carrying malaria parasites were followed by home visit and phone calls for compliance to treatment, and filter paper blood blots collected from participants were used to determine true parasite carriage by PET-PCR. A mathematical model of the study site was developed and used to test the impact of test sensitivity and mass migration on the effect of MTTT. RESULTS The start and end point sensitivities of the cRDT were 48.8% and 41.7% and those for the uRDT were 52.9% and 59.9% respectively. After a year of MTTTs, asymptomatic parasite prevalence, as determined by PCR, did not differ statistically in the control site (40.6% to 40.1%, P = 0.730) but decreased at the intervention site (55.9% to 46.4%, P < 0.0001). Parasite prevalence by RDT, however, indicated statistical reduction in the control site (25.3% to 22.3%, P = 0.017) and no change in the intervention site (35.1% to 36.0%, P = 0.614). The model predicted a mild effect of both diagnostic sensitivity and human movement in diminishing the impact of MTTT in the study sites. CONCLUSIONS Asymptomatic parasite prevalence at the molecular level reduced significantly in the site where the uRDT was used but not where the cRDT was used. Overall, the uRDT exhibited higher sensitivity relative to the cRDT. Highly sensitive molecular techniques such as PET-PCR should be included in parasite prevalence estimation during MTTT exercises.
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Affiliation(s)
- Linda Eva Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
| | - Ndong Ignatius Cheng
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Festus Kojo Acquah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Susan Adu-Amankwah
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Dorcas Gyama Bredu
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Benedicta A Mensah
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Sherik-Fa Anang
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Bernice Cubson Abban
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Abena Busayomi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Sebastian Shine Kwarpong
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Prosper Kofi Tey
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Elizabeth Cudjoe
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | | | - Tobias McKenzie Holden
- Department of Preventive Medicine and Institute for Global Health, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Jaline Gerardin
- Department of Preventive Medicine and Institute for Global Health, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Justice Nonvignon
- Department of Health Policy, Planning and Management, School of Public Health, College of Health Sciences, University of Ghana, P. O. Box LG13, Legon, Ghana
| | - Collins Ahorlu
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
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Diffendall G, Claes A, Barcons-Simon A, Nyarko P, Dingli F, Santos MM, Loew D, Claessens A, Scherf A. RNA polymerase III is involved in regulating Plasmodium falciparum virulence. eLife 2024; 13:RP95879. [PMID: 38921824 PMCID: PMC11208047 DOI: 10.7554/elife.95879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024] Open
Abstract
While often undetected and untreated, persistent seasonal asymptomatic malaria infections remain a global public health problem. Despite the presence of parasites in the peripheral blood, no symptoms develop. Disease severity is correlated with the levels of infected red blood cells (iRBCs) adhering within blood vessels. Changes in iRBC adhesion capacity have been linked to seasonal asymptomatic malaria infections, however how this is occurring is still unknown. Here, we present evidence that RNA polymerase III (RNA Pol III) transcription in Plasmodium falciparum is downregulated in field isolates obtained from asymptomatic individuals during the dry season. Through experiments with in vitro cultured parasites, we have uncovered an RNA Pol III-dependent mechanism that controls pathogen proliferation and expression of a major virulence factor in response to external stimuli. Our findings establish a connection between P. falciparum cytoadhesion and a non-coding RNA family transcribed by Pol III. Additionally, we have identified P. falciparum Maf1 as a pivotal regulator of Pol III transcription, both for maintaining cellular homeostasis and for responding adaptively to external signals. These results introduce a novel perspective that contributes to our understanding of P. falciparum virulence. Furthermore, they establish a connection between this regulatory process and the occurrence of seasonal asymptomatic malaria infections.
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Affiliation(s)
- Gretchen Diffendall
- Institut Pasteur, Universite Paris CitéParisFrance
- Institut Pasteur, Sorbonne Université Ecole doctorale Complexité du VivantParisFrance
| | | | - Anna Barcons-Simon
- Institut Pasteur, Universite Paris CitéParisFrance
- Institut Pasteur, Sorbonne Université Ecole doctorale Complexité du VivantParisFrance
- Institut Pasteur, Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität MünchenMunichGermany
| | - Prince Nyarko
- Institut Pasteur, Laboratory of Pathogen-Host Interaction (LPHI), CNRS, University of MontpellierMontpellierFrance
| | - Florent Dingli
- Institut Pasteur, Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry ProteomicsParisFrance
| | - Miguel M Santos
- Institut Pasteur, Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de LisboaLisboaPortugal
| | - Damarys Loew
- Institut Pasteur, Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry ProteomicsParisFrance
| | - Antoine Claessens
- Institut Pasteur, Laboratory of Pathogen-Host Interaction (LPHI), CNRS, University of MontpellierMontpellierFrance
- Institut Pasteur, LPHI, MIVEGEC, CNRS, INSERM, University of MontpellierMontpellierFrance
| | - Artur Scherf
- Institut Pasteur, Universite Paris CitéParisFrance
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Prah DA, Laryea-Akrong E. Asymptomatic Low-Density Plasmodium falciparum Infections: Parasites Under the Host's Immune Radar? J Infect Dis 2024; 229:1913-1918. [PMID: 38349649 PMCID: PMC11175676 DOI: 10.1093/infdis/jiad581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 12/18/2023] [Indexed: 06/15/2024] Open
Abstract
A large body of evidence suggests that low parasite carriage in Plasmodium falciparum asymptomatic infection is required for the maintenance of malaria immunity. However, the fact that treating such infections has little to no impact on subsequent clinical malaria is rarely noted. In this paper, we review data and argue that low-density parasite carriage in asymptomatic infection may not support host immune processes and that parasites are virtually under the host's immunological radar. We also discuss factors that may be constraining parasitemia in asymptomatic infections from reaching the threshold required to cause clinical symptoms. A thorough understanding of this infectious reservoir is essential for malaria control and eradication because asymptomatic infections contribute significantly to Plasmodium transmission.
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Affiliation(s)
- Diana Ahu Prah
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
- Faculty of Applied Sciences, Department of Science Laboratory Technology, Accra Technical University, Accra, Ghana
| | - Elizabeth Laryea-Akrong
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
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4
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Orish VN, Lokpo SY, Kwadzokpui PK, Safianu R, Marinkovic A, Prakash S, Okorie C, Izurieta R, Pandit R, Sanyaolu A. Association between asymptomatic Plasmodium falciparum malaria infection, anaemia and mean corpuscular volume of school children in the Volta Region of Ghana. Eur J Microbiol Immunol (Bp) 2024; 14:195-201. [PMID: 38407577 PMCID: PMC11097786 DOI: 10.1556/1886.2024.00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 02/13/2024] [Indexed: 02/27/2024] Open
Abstract
Background Although, several studies have reported abnormal Mean Corpuscular Volume (MCV) values and anaemia associated with malaria infections with a focus on Plasmodium falciparum among patients with complicated and uncomplicated malaria, none has looked at the association with asymptomatic malaria. This study aimed to assess this association. Methods We conducted a cross-sectional study using 3 mL of blood samples from 549 children aged 5-17 years attending 5 schools selected in the Volta Region. Semi-structured questionnaires were administered to the children to obtain demographic data. Blood samples were collected to estimate the children's full blood count (FBC) and malaria status. Data obtained were analysed using STATA 15 software. P-values of less than 0.05 were considered statistically significant. Results Most of the children in this study (49.9%) had normal MCV (81.3-91.3 fL) with an overall malaria prevalence of 55.6 % (95% CI: 51.3-59.8) and anaemia prevalence of 48.6% (95% CI 44.4-52.9). Most anaemic children had normal MCV (81.3-91.3 fL) (49.8, 95% CI 43.7-56.0). The predicted probability of malaria was highly likely among children with normal MCV (81.3-91.3 fL) but with high variability and uncertainty among those with low MCV (<81.3 fL) and high MCV (>91.3 fL). Conclusion This study shows a reduced predicted probability of malaria among children with low and high MCV, playing a protective function against malaria. Further studies are required to elucidate the interaction.
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Affiliation(s)
- Verner N. Orish
- Department of Microbiology and Immunology, School of Medicine, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Sylvester Y. Lokpo
- Department of Medical Laboratory Sciences, School of Allied Health Sciences, University of Health and Allied Sciences, Ho, Ghana
| | | | - Rufai Safianu
- Department of Basic Medical Sciences, School of Medicine, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | | | | | - Chuku Okorie
- Union County College (Plainfield Campus), Plainfield, NJ, USA
| | - Ricardo Izurieta
- Global Communicable Diseases, College of Public Health, University of South Florida, Tampa, FL, USA
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Fogang B, Lellouche L, Ceesay S, Drammeh S, Jaiteh FK, Guery MA, Landier J, Haanappel CP, Froberg J, Conway D, D'Alessandro U, Bousema T, Claessens A. Asymptomatic Plasmodium falciparum carriage at the end of the dry season is associated with subsequent infection and clinical malaria in Eastern Gambia. Malar J 2024; 23:22. [PMID: 38229097 DOI: 10.1186/s12936-024-04836-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 01/03/2024] [Indexed: 01/18/2024] Open
Abstract
BACKGROUND Chronic carriage of asymptomatic low-density Plasmodium falciparum parasitaemia in the dry season may support maintenance of acquired immunity that protects against clinical malaria. However, the relationship between chronic low-density infections and subsequent risk of clinical malaria episodes remains unclear. METHODS In a 2-years study (December 2014 to December 2016) in eastern Gambia, nine cross-sectional surveys using molecular parasite detection were performed in the dry and wet season. During the 2016 malaria transmission season, passive case detection identified episodes of clinical malaria. RESULTS Among the 5256 samples collected, 444 (8.4%) were positive for P. falciparum. A multivariate model identified village of residence, male sex, age ≥ 5 years old, anaemia, and fever as independent factors associated with P. falciparum parasite carriage. Infections did not cluster over time within the same households or recurred among neighbouring households. Asymptomatic parasite carriage at the end of dry season was associated with a higher risk of infection (Hazard Ratio, HR = 3.0, p < 0.0001) and clinical malaria (HR = 1.561, p = 0.057) during the following transmission season. Age and village of residence were additional predictors of infection and clinical malaria during the transmission season. CONCLUSION Chronic parasite carriage during the dry season is associated with an increased risk of malaria infection and clinical malaria. It is unclear whether this is due to environmental exposure or to other factors.
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Affiliation(s)
- Balotin Fogang
- LPHI, MIVEGEC, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Lionel Lellouche
- LPHI, MIVEGEC, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Sukai Ceesay
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Sainabou Drammeh
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Fatou K Jaiteh
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Marc-Antoine Guery
- LPHI, MIVEGEC, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Jordi Landier
- IRD, INSERM, SESSTIM, ISSPAM, Aix Marseille University, 27 Boulevard Jean Moulin, 13005, Marseille, France
| | - Cynthia P Haanappel
- Department of Medical Microbiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Janeri Froberg
- Department of Medical Microbiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - David Conway
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Teun Bousema
- Department of Medical Microbiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Antoine Claessens
- LPHI, MIVEGEC, CNRS, INSERM, University of Montpellier, Montpellier, France.
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia.
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Qidwai T. Cytokine storm in COVID-19 and malaria: Annals of pro-inflammatory cytokines. Cytokine 2024; 173:156420. [PMID: 37976701 DOI: 10.1016/j.cyto.2023.156420] [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: 07/24/2023] [Revised: 10/28/2023] [Accepted: 11/01/2023] [Indexed: 11/19/2023]
Abstract
Infectious diseases are affecting the people worldwide. Mostly, infectious agents activate excessive production of cytokines so called cytokine storm. Among the infectious diseases COVID-19 is one of the deadliest diseases affecting individuals all over the world, moreover, Plasmodium falciparum malaria and HIV are major killers. An excessive pro-inflammatory response is one of the major causes of pathological conditions in these diseases. It is important to investigate the pathophysiology in the infectious diseases such as COVID-19, malaria and HIV as there is no concrete therapy against them so far. Exploration of excessive pro-inflammation could be important for therapeutic intervention. In this article, an attempt has been made to analyze the pathological conditions arise due to excessive inflammatory response in COVID-19, malaria and other infectious diseases. Targeting excessive pro-inflammatory response/cytokine storm in infectious diseases could be a useful strategy.
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Affiliation(s)
- Tabish Qidwai
- Faculty of Biotechnology, Shri Ramswaroop Memorial University, Lucknow Deva Road, Uttar Pradesh 225003, India.
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Abosalif KOA, Abdalla AE, Junaid K, Eltayeb LB, Ejaz H. The interleukin-10 family: Major regulators of the immune response against Plasmodium falciparum infections. Saudi J Biol Sci 2023; 30:103805. [PMID: 37727525 PMCID: PMC10506046 DOI: 10.1016/j.sjbs.2023.103805] [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: 08/05/2023] [Revised: 08/16/2023] [Accepted: 09/01/2023] [Indexed: 09/21/2023] Open
Abstract
Malaria caused by the Plasmodium falciparum strain is more severe because of this protozoan's ability to disrupt the physiology of host cells during the blood stages of development by initiating the production of the interleukin-10 (IL-10) family of cytokines. P. falciparum feeds on hemoglobin and causes host cells to adhere to the walls of blood vessels by remodeling their composition. IL-10 is produced by CD4+ T cells that inhibits antigen-presenting cells' activity to prevent inflammation. This cytokine and its family members are crucial in promoting malarial infection by inhibiting the host's protective immune response, thus initiating Plasmodium parasitemia. IL-10 is also responsible for preventing severe pathology during Plasmodium infection and initiates several signaling pathways to alter the physiology of host cells during malarial infection. This review summarizes the critical aspects of P. falciparum infection, including its role in signaling pathways for cytokine exudation, its effect on microRNA, the human immune response in malaria, and the role played by the liver hormone hepcidin. Moreover, future aspects of vaccine development and therapeutic strategies to combat P. falciparum infections are also discussed in detail.
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Affiliation(s)
- Khalid Omer Abdalla Abosalif
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia
| | - Abualgasim Elgaili Abdalla
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia
| | - Kashaf Junaid
- School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Lienda Bashier Eltayeb
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Prince Sattam Bin AbdulAziz University- Al-Kharj, 11942 Riyadh, Saudi Arabia
| | - Hasan Ejaz
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72388, Saudi Arabia
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Biruksew A, Demeke A, Birhanu Z, Golassa L, Getnet M, Yewhalaw D. Schoolchildren with asymptomatic malaria are potential hotspot for malaria reservoir in Ethiopia: implications for malaria control and elimination efforts. Malar J 2023; 22:311. [PMID: 37845680 PMCID: PMC10580533 DOI: 10.1186/s12936-023-04736-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/30/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Schoolchildren with asymptomatic malaria infections often go undiagnosed and untreated, serving as reservoirs for infection that hamper malaria control and elimination efforts. In this context, little is known about the magnitude of asymptomatic malaria infections in apparently healthy schoolchildren in Ethiopia. This study was aimed at determining the prevalence of asymptomatic malaria infection and its associated factors in apparently healthy schoolchildren in Ethiopia. METHODS From September 2021 to January 2022, a school-based cross-sectional study was conducted on 994 apparently healthy schoolchildren (aged 6-15 years) selected from 21 primary schools in the Gomma district, of Jimma zone, southwestern Oromia, Ethiopia. A multi-stage sampling technique was used to select schools and participants. After allocating the total sample proportionally to each school and then to each grade, participants were selected using the lottery method from a list of student records (rosters). Finger-pricked blood samples were collected for microscopy blood film preparation and malaria rapid diagnostic test (RDT) (SD Bioline Malaria Ag Pf/Pv). Moreover, dry blood spots (DBSs) were prepared onto filter papers for quantitative real time polymerase chain reaction (qPCR) analysis. RESULTS As determined by RDT and microscopy, the prevalence of asymptomatic malaria was 2.20% and 1.51%, respectively. Using qPCR, the overall prevalence was 5.03% (50/994). Of this, Plasmodium falciparum, Plasmodium vivax and mixed infections accounted for 90%, 6% and 4%, respectively. Submicroscopic asymptomatic malaria infection was also accounted for 70% (35/50) of the overall prevalence. Household head age, nighttime outdoor activities of household heads, family history of malaria, absence of insecticide-treated nets (ITN), and presence of stagnant water around the houses are all significantly associated with asymptomatic malaria infections among schoolchildren. CONCLUSIONS This study found that both RDT and microscopy underestimated the prevalence of asymptomatic malaria in schoolchildren. However, qPCR was able to detect even low levels of parasitaemia and revealed a higher prevalence of asymptomatic submicroscopic malaria infections. The findings imply that schoolchildren with asymptomatic malaria infection are potential hotspot for malaria reservoir that fuels ongoing transmission. Therefore, it is imperative to include schoolchildren and schools in malaria intervention package and equally important is the adoption of more advanced and sensitive diagnostic tools, which would be crucial for successful malaria control and elimination efforts. Targeted interventions for asymptomatic malaria-infected schoolchildren can provide invaluable support to the National Malaria Control Programme in controlling and eventually eliminating the disease.
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Affiliation(s)
- Abdissa Biruksew
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIRC), Jimma University, Jimma, Ethiopia
| | | | - Zewdie Birhanu
- Department of Health, Behavior, and Society, Faculty of Public Health, Institute of Health Jimma University, Jimma, Ethiopia
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Masrie Getnet
- Department of Biostatistics and Epidemiology, Faculty of Public Health, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIRC), Jimma University, Jimma, Ethiopia
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Ngum NH, Fakeh NB, Lem AE, Mahamat O. Prevalence of malaria and associated clinical manifestations and myeloperoxidase amongst populations living in different altitudes of Mezam division, North West Region, Cameroon. Malar J 2023; 22:20. [PMID: 36658587 PMCID: PMC9850770 DOI: 10.1186/s12936-022-04438-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 12/31/2022] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Malaria is a growing problem in Africa, with prevalence varies from areas to areas due to several factors including the altitude. This study aimed to investigate the malaria distribution and its relationship with level of some blood parameters and plasma myeloperoxidase (MPO) in population of three localities with different altitudes. METHODS A total of 150 participants were recruited in each locality and facial body temperature of each was measured using a forehead digital thermometer. Blood samples were collected and used diagnose malaria parasite using the rapid test followed by Giemsa stain microscopy and have the full blood count and MPO level using a colorimetric method. RESULTS The overall prevalence of falciparum malaria was 34.7%, with no difference between the three communities, but Bambili of high altitude had the highest prevalence (70.7%). A majority of the infected persons had mild malaria, with most cases being asymptomatic (temperature < 37.5 ºC). Patients had significant increase of geometric mean malaria parasite density (GMPD) in Bambili (1755 ± 216 parasites/µL) and Bamenda (1060 ± 2515 parasites/µL of blood) than patients in Santa (737 ± 799 parasites/µL). There was a significant risk to have malaria infection in Bambili (OR = 33.367, p = 0.021) than in Santa (OR = 2.309, p = 0.362). Bambili' participants of 6-10 years showed a high prevalence of malaria (85.7%). GMPD was significantly different between males (p = 0.010) as well as females (p = 0.000). Participants from Santa (11.2 ± 3.2 g/dL) and Bambili (12.6 ± 2.4 g/dL) had a high haemoglobin concentration than those from Bamenda (10.6 ± 2.1 g/dL). There was a significant difference in the WBC counts and platelet counts among infected participants in the study areas. MPO level had an increasing trend among infected participants in Santa (2.378 ± 0.250), Bambili (2.582 ± 0.482) and Bamenda (2.635 ± 0.466). CONCLUSION The results of the present study demonstrated that altitudinal variations significant impact the risk of population to have malaria with high parasitaemia and may contribute to the malaria prevalence and severity by affecting the haemoglobin concentration, WBC and platelet level and plasma MPO in population.
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Affiliation(s)
- Ntonifor Helen Ngum
- grid.449799.e0000 0004 4684 0857Department of Biological Sciences, Faculty of Science, The University of Bamenda, BP 39, Bambili, N. W. Region Cameroon ,grid.442553.10000 0004 0622 6369African Centre of Excellence for Genomics of Infectious Diseases (ACEGID), Redeemer’s University, Ede, Osun State Nigeria
| | - Ngahbort Belthine Fakeh
- grid.449799.e0000 0004 4684 0857Department of Biological Sciences, Faculty of Science, The University of Bamenda, BP 39, Bambili, N. W. Region Cameroon
| | - Abongwa Edith Lem
- grid.449799.e0000 0004 4684 0857Department of Biological Sciences, Faculty of Science, The University of Bamenda, BP 39, Bambili, N. W. Region Cameroon ,grid.442553.10000 0004 0622 6369African Centre of Excellence for Genomics of Infectious Diseases (ACEGID), Redeemer’s University, Ede, Osun State Nigeria
| | - Oumar Mahamat
- grid.449799.e0000 0004 4684 0857Department of Biological Sciences, Faculty of Science, The University of Bamenda, BP 39, Bambili, N. W. Region Cameroon
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Mahittikorn A, Mala W, Srisuphanunt M, Masangkay FR, Kotepui KU, Wilairatana P, Kotepui M. Tumour necrosis factor-α as a prognostic biomarker of severe malaria: a systematic review and meta-analysis. J Travel Med 2022; 29:6573410. [PMID: 35467747 DOI: 10.1093/jtm/taac053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 11/14/2022]
Abstract
BACKGROUND Tumour necrosis factor-alpha (TNF-α) levels are reportedly altered during malaria. In this systematic review and meta-analysis, we aimed to collect and compare data on TNF-α levels between patients with malaria of varying severity and healthy asymptomatic positive controls. METHODS We searched PubMed, Scopus and Web of Science for studies that reported TNF-α levels in malaria cases of different severity and healthy asymptomatic positive controls using a combination of search terms. The quality of the included studies was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology checklist. To compare the TNF-α levels among fatal cases, severe cases, uncomplicated cases and healthy asymptomatic positive controls, we applied the random-effects model that assumed the existence of variations between studies. The effect estimate was pooled mean difference (MD) with a 95% confidence interval (CI). RESULTS From 1694 studies, we included 31 studies that met our eligibility criteria for systematic review and meta-analysis. Patients with severe malaria showed higher mean TNF-α levels than those with uncomplicated malaria (P < 0.001, pooled MD = 79.02 pg/ml, 95% CI: 63.68-94.35 pg/ml, I2: 99.5%, n = 26 studies). Furthermore, fatal cases had no difference in the mean TNF-α levels in comparison with survived cases (P = 0.055, pooled MD = 82.38 pg/ml, 95% CI: -1.93 to 166.69 pg/ml, I2: 99.54%, n = 5 studies). Finally, patients with uncomplicated malaria showed higher mean TNF-α levels than those with asymptomatic malaria (P < 0.001, pooled MD = 45.10 pg/ml, 95% CI: 18.45-71.76 pg/ml, I2: 97.09%, n = 5 studies). CONCLUSION This systematic review and meta-analysis confirmed the increase of TNF-α levels in patients with severe malaria. Therefore, TNF-α may be alternatively used as a prognostic biomarker of severe malaria. TRIAL REGISTRATION Not applicable.
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Affiliation(s)
- Aongart Mahittikorn
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wanida Mala
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Mayuna Srisuphanunt
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | | | - Kwuntida Uthaisar Kotepui
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Manas Kotepui
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
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11
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Hergott DEB, Owalla TJ, Balkus JE, Apio B, Lema J, Cemeri B, Akileng A, Seilie AM, Chavtur C, Staubus W, Chang M, Egwang TG, Murphy SC. Feasibility of community at-home dried blood spot collection combined with pooled reverse transcription PCR as a viable and convenient method for malaria epidemiology studies. Malar J 2022; 21:221. [PMID: 35836179 PMCID: PMC9284728 DOI: 10.1186/s12936-022-04239-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/26/2022] [Indexed: 01/08/2023] Open
Abstract
Background Many Plasmodium infections in endemic regions exist at densities below the limit of detection of standard diagnostic tools. These infections threaten control efforts and may impact vaccine and therapeutic drug studies. Simple, cost-effective methods are needed to study the natural history of asymptomatic submicroscopic parasitaemia. Self-collected dried blood spots (DBS) analysed using pooled and individual quantitative reverse transcription polymerase chain reaction (qRT-PCR) provide such a solution. Here, the feasibility and acceptability of daily at-home DBS collections for qRT-PCR was studied to better understand low-density infections. Methods Rapid diagnostic test (RDT)-negative individuals in Katakwi District, northeastern Uganda, were recruited between April and May 2021. Venous blood samples and clinic-collected DBS were taken at enrollment and at four weekly clinic visits. Participants were trained in DBS collection and asked to collect six DBS weekly between clinic visits. Opinions about the collection process were solicited using daily Diary Cards and a Likert scale survey at the final study visit. Venous blood and DBS were analysed by Plasmodium 18S rRNA qRT-PCR. The number of participants completing the study, total DBS collected, and opinions of the process were analysed to determine compliance and acceptability. The human internal control mRNA and Plasmodium 18S rRNA were evaluated for at-home vs. clinic-collected DBS and venous blood to assess quality and accuracy of at-home collected samples. Results One-hundred two adults and 29 children were enrolled, and 95 and 26 completed the study, respectively. Three individuals withdrew due to pain or inconvenience of procedures. Overall, 96% of participants collected ≥ 16 of 24 at-home DBS, and 87% of DBS contained ≥ 40 µL of blood. The procedure was well tolerated and viewed favourably by participants. At-home collected DBS were acceptable for qRT-PCR and showed less than a one qRT-PCR cycle threshold shift in the human control mRNA compared to clinic-collected DBS. Correlation between Plasmodium falciparum 18S rRNA from paired whole blood and DBS was high (R = 0.93). Conclusions At-home DBS collection is a feasible, acceptable, and robust method to obtain blood to evaluate the natural history of low-density Plasmodium infections by qRT-PCR. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04239-x.
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Affiliation(s)
- Dianna E B Hergott
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican St., F870, Seattle, WA, 98109, USA.,Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, USA
| | - Tonny J Owalla
- Med Biotech Laboratories, P.O. Box 9364, Kampala, Uganda
| | - Jennifer E Balkus
- Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, USA
| | | | - Jimmy Lema
- Med Biotech Laboratories, P.O. Box 9364, Kampala, Uganda
| | - Barbara Cemeri
- Med Biotech Laboratories, P.O. Box 9364, Kampala, Uganda
| | - Andrew Akileng
- Med Biotech Laboratories, P.O. Box 9364, Kampala, Uganda
| | - Annette M Seilie
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican St., F870, Seattle, WA, 98109, USA.,Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, Seattle, WA, USA
| | - Chris Chavtur
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican St., F870, Seattle, WA, 98109, USA.,Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, Seattle, WA, USA
| | - Weston Staubus
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican St., F870, Seattle, WA, 98109, USA.,Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, Seattle, WA, USA
| | - Ming Chang
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican St., F870, Seattle, WA, 98109, USA.,Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, Seattle, WA, USA
| | | | - Sean C Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, 750 Republican St., F870, Seattle, WA, 98109, USA. .,Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, Seattle, WA, USA. .,Department of Microbiology, University of Washington, Seattle, WA, USA.
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12
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Kimenyi KM, Wamae K, Ngoi JM, de Laurent ZR, Ndwiga L, Osoti V, Obiero G, Abdi AI, Bejon P, Ochola-Oyier LI. Maintenance of high temporal Plasmodium falciparum genetic diversity and complexity of infection in asymptomatic and symptomatic infections in Kilifi, Kenya from 2007 to 2018. Malar J 2022; 21:192. [PMID: 35725456 PMCID: PMC9207840 DOI: 10.1186/s12936-022-04213-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/03/2022] [Indexed: 11/30/2022] Open
Abstract
Background High levels of genetic diversity are common characteristics of Plasmodium falciparum parasite populations in high malaria transmission regions. There has been a decline in malaria transmission intensity over 12 years of surveillance in the community in Kilifi, Kenya. This study sought to investigate whether there was a corresponding reduction in P. falciparum genetic diversity, using msp2 as a genetic marker. Methods Blood samples were obtained from children (< 15 years) enrolled into a cohort with active weekly surveillance between 2007 and 2018 in Kilifi, Kenya. Asymptomatic infections were defined during the annual cross-sectional blood survey and the first-febrile malaria episode was detected during the weekly follow-up. Parasite DNA was extracted and successfully genotyped using allele-specific nested polymerase chain reactions for msp2 and capillary electrophoresis fragment analysis. Results Based on cross-sectional surveys conducted in 2007–2018, there was a significant reduction in malaria prevalence (16.2–5.5%: P-value < 0.001), however msp2 genetic diversity remained high. A high heterozygosity index (He) (> 0.95) was observed in both asymptomatic infections and febrile malaria over time. About 281 (68.5%) asymptomatic infections were polyclonal (> 2 variants per infection) compared to 46 (56%) polyclonal first-febrile infections. There was significant difference in complexity of infection (COI) between asymptomatic 2.3 [95% confidence interval (CI) 2.2–2.5] and febrile infections 2.0 (95% CI 1.7–2.3) (P = 0.016). Majority of asymptomatic infections (44.2%) carried mixed alleles (i.e., both FC27 and IC/3D7), while FC27 alleles were more frequent (53.3%) among the first-febrile infections. Conclusions Plasmodium falciparum infections in Kilifi are still highly diverse and polyclonal, despite the reduction in malaria transmission in the community. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04213-7.
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Affiliation(s)
- Kelvin M Kimenyi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya. .,Department of Biochemistry, University of Nairobi, Nairobi, Kenya.
| | - Kevin Wamae
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Joyce M Ngoi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,West Africa Centre for Cell Biology and Infectious Pathogen, Accra, Ghana
| | | | | | - Victor Osoti
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - George Obiero
- Department of Biochemistry, University of Nairobi, Nairobi, Kenya
| | | | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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13
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Kobia FM, Maiti K, Obimbo MM, Smith R, Gitaka J. Potential pharmacologic interventions targeting TLR signaling in placental malaria. Trends Parasitol 2022; 38:513-524. [DOI: 10.1016/j.pt.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/07/2022] [Accepted: 04/07/2022] [Indexed: 10/18/2022]
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14
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Idro R, Ogwang R, Barragan A, Raimondo JV, Masocha W. Neuroimmunology of Common Parasitic Infections in Africa. Front Immunol 2022; 13:791488. [PMID: 35222377 PMCID: PMC8866860 DOI: 10.3389/fimmu.2022.791488] [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: 10/08/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
Parasitic infections of the central nervous system are an important cause of morbidity and mortality in Africa. The neurological, cognitive, and psychiatric sequelae of these infections result from a complex interplay between the parasites and the host inflammatory response. Here we review some of the diseases caused by selected parasitic organisms known to infect the nervous system including Plasmodium falciparum, Toxoplasma gondii, Trypanosoma brucei spp., and Taenia solium species. For each parasite, we describe the geographical distribution, prevalence, life cycle, and typical clinical symptoms of infection and pathogenesis. We pay particular attention to how the parasites infect the brain and the interaction between each organism and the host immune system. We describe how an understanding of these processes may guide optimal diagnostic and therapeutic strategies to treat these disorders. Finally, we highlight current gaps in our understanding of disease pathophysiology and call for increased interrogation of these often-neglected disorders of the nervous system.
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Affiliation(s)
- Richard Idro
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Rodney Ogwang
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda.,Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Antonio Barragan
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Joseph Valentino Raimondo
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Willias Masocha
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Safat, Kuwait
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15
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Addy JW, Bediako Y, Ndungu FM, Valetta JJ, Reid AJ, Mwacharo J, Ngoi JM, Wambua J, Otieno E, Musyoki J, Said K, Berriman M, Marsh K, Bejon P, Recker M, Langhorne J. 10-year longitudinal study of malaria in children: Insights into acquisition and maintenance of naturally acquired immunity. Wellcome Open Res 2022; 6:79. [PMID: 35141425 PMCID: PMC8822141 DOI: 10.12688/wellcomeopenres.16562.3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2022] [Indexed: 01/26/2023] Open
Abstract
Background: Studies of long-term malaria cohorts have provided essential insights into how Plasmodium falciparum interacts with humans, and influences the development of antimalarial immunity. Immunity to malaria is acquired gradually after multiple infections, some of which present with clinical symptoms. However, there is considerable variation in the number of clinical episodes experienced by children of the same age within the same cohort. Understanding this variation in clinical symptoms and how it relates to the development of naturally acquired immunity is crucial in identifying how and when some children stop experiencing further malaria episodes. Where variability in clinical episodes may result from different rates of acquisition of immunity, or from variable exposure to the parasite. Methods: Using data from a longitudinal cohort of children residing in an area of moderate P. falciparum transmission in Kilifi district, Kenya, we fitted cumulative episode curves as monotonic-increasing splines, to 56 children under surveillance for malaria from the age of 5 to 15. Results: There was large variability in the accumulation of numbers of clinical malaria episodes experienced by the children, despite being of similar age and living in the same general location. One group of children from a particular sub-region of the cohort stopped accumulating clinical malaria episodes earlier than other children in the study. Despite lack of further clinical episodes of malaria, these children had higher asymptomatic parasite densities and higher antibody titres to a panel of P. falciparum blood-stage antigens. Conclusions: This suggests development of clinical immunity rather than lack of exposure to the parasite, and supports the view that this immunity to malaria disease is maintained by a greater exposure to P. falciparum, and thus higher parasite burdens. Our study illustrates the complexity of anti-malaria immunity and underscores the need for analyses which can sufficiently reflect the heterogeneity within endemic populations.
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Affiliation(s)
- John W.G. Addy
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
| | - Yaw Bediako
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | | | - John Joseph Valetta
- School of Mathematics and Statistics, University of St Andrews, St Andrews, UK
| | - Adam J. Reid
- Parasite Genomics, Wellcome Sanger Institute, Hixton, UK
| | | | | | - Joshua Wambua
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Edward Otieno
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Khadija Said
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Kevin Marsh
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Philip Bejon
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mario Recker
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Jean Langhorne
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
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16
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Gupta H, Wassmer SC. Harnessing the Potential of miRNAs in Malaria Diagnostic and Prevention. Front Cell Infect Microbiol 2021; 11:793954. [PMID: 34976869 PMCID: PMC8716737 DOI: 10.3389/fcimb.2021.793954] [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] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 11/09/2021] [Indexed: 12/14/2022] Open
Abstract
Despite encouraging progress over the past decade, malaria remains a major global health challenge. Its severe form accounts for the majority of malaria-related deaths, and early diagnosis is key for a positive outcome. However, this is hindered by the non-specific symptoms caused by malaria, which often overlap with those of other viral, bacterial and parasitic infections. In addition, current tools are unable to detect the nature and degree of vital organ dysfunction associated with severe malaria, as complications develop silently until the effective treatment window is closed. It is therefore crucial to identify cheap and reliable early biomarkers of this wide-spectrum disease. microRNAs (miRNAs), a class of small non-coding RNAs, are rapidly released into the blood circulation upon physiological changes, including infection and organ damage. The present review details our current knowledge of miRNAs as biomarkers of specific organ dysfunction in patients with malaria, and both promising candidates identified by pre-clinical models and important knowledge gaps are highlighted for future evaluation in humans. miRNAs associated with infected vectors are also described, with a view to expandind this rapidly growing field of research to malaria transmission and surveillance.
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Affiliation(s)
- Himanshu Gupta
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Samuel C. Wassmer
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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17
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Addy JW, Bediako Y, Ndungu FM, Valetta JJ, Reid AJ, Mwacharo J, Ngoi JM, Wambua J, Otieno E, Musyoki J, Said K, Berriman M, Marsh K, Bejon P, Recker M, Langhorne J. 10-year longitudinal study of malaria in children: Insights into acquisition and maintenance of naturally acquired immunity. Wellcome Open Res 2021; 6:79. [PMID: 35141425 PMCID: PMC8822141 DOI: 10.12688/wellcomeopenres.16562.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2021] [Indexed: 01/26/2023] Open
Abstract
Background: Studies of long-term malaria cohorts have provided essential insights into how Plasmodium falciparum interacts with humans, and influences the development of antimalarial immunity. Immunity to malaria is acquired gradually after multiple infections, some of which present with clinical symptoms. However, there is considerable variation in the number of clinical episodes experienced by children of the same age within the same cohort. Understanding this variation in clinical symptoms and how it relates to the development of naturally acquired immunity is crucial in identifying how and when some children stop experiencing further malaria episodes. Where variability in clinical episodes may result from different rates of acquisition of immunity, or from variable exposure to the parasite. Methods: Using data from a longitudinal cohort of children residing in an area of moderate P. falciparum transmission in Kilifi district, Kenya, we fitted cumulative episode curves as monotonic-increasing splines, to 56 children under surveillance for malaria from the age of 5 to 15. Results: There was large variability in the accumulation of numbers of clinical malaria episodes experienced by the children, despite being of similar age and living in the same general location. One group of children from a particular sub-region of the cohort stopped accumulating clinical malaria episodes earlier than other children in the study. Despite lack of further clinical episodes of malaria, these children had higher asymptomatic parasite densities and higher antibody titres to a panel of P. falciparum blood-stage antigens. Conclusions: This suggests development of clinical immunity rather than lack of exposure to the parasite, and supports the view that this immunity to malaria disease is maintained by a greater exposure to P. falciparum, and thus higher parasite burdens. Our study illustrates the complexity of anti-malaria immunity and underscores the need for analyses which can sufficiently reflect the heterogeneity within endemic populations.
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Affiliation(s)
- John W.G. Addy
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
| | - Yaw Bediako
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | | | - John Joseph Valetta
- School of Mathematics and Statistics, University of St Andrews, St Andrews, UK
| | - Adam J. Reid
- Parasite Genomics, Wellcome Sanger Institute, Hixton, UK
| | | | | | - Joshua Wambua
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Edward Otieno
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Khadija Said
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Kevin Marsh
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Philip Bejon
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mario Recker
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Jean Langhorne
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
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18
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The determinants of lipid profiles in early adolescence in a Ugandan birth cohort. Sci Rep 2021; 11:16503. [PMID: 34389769 PMCID: PMC8363641 DOI: 10.1038/s41598-021-96035-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 08/02/2021] [Indexed: 12/04/2022] Open
Abstract
Dyslipidaemia in adolescence tracks into adulthood and is an important risk factor for cardiovascular disease. Little is known about the effects of environmental exposures and early-life exposure to infectious diseases common to tropical regions on lipids. In 1119 early adolescent participants in the Entebbe Mother and Baby Study, we used linear regression to examine whether prenatal, childhood or adolescent factors are associated with lipid levels. Reduced high-density lipoprotein (HDL) and elevated triglyceride levels were common (prevalence 31% and 14%, respectively), but elevated low-density lipoprotein (LDL) or total cholesterol (TC) were rare. Current malaria infection was associated with lower mean LDL (adjusted ß − 0.51; 95% CI − 0.81, − 0.21), HDL (adjusted ß − 0.40; 95% CI − 0.56, − 0.23), and TC levels (adjusted ß − 0.62; 95% CI − 0.97, − 0.27), but higher mean triglyceride levels (geometric mean ratio (GMR) 1.47; 95% CI 1.18–1.84). Early-life asymptomatic malaria was associated with modest reductions in HDL and TC. Body mass index (BMI) was positively associated with LDL, TC, and triglycerides. No associations with helminth infection were found. Our findings suggest that early-life factors have only marginal effects on the lipid profile. Current malaria infection and BMI are strongly associated with lipids and important to consider when trying to improve the lipid profile.
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19
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Odhiambo JN, Kalinda C, Macharia PM, Snow RW, Sartorius B. Spatial and spatio-temporal methods for mapping malaria risk: a systematic review. BMJ Glob Health 2021; 5:bmjgh-2020-002919. [PMID: 33023880 PMCID: PMC7537142 DOI: 10.1136/bmjgh-2020-002919] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/23/2020] [Accepted: 08/24/2020] [Indexed: 12/21/2022] Open
Abstract
Background Approaches in malaria risk mapping continue to advance in scope with the advent of geostatistical techniques spanning both the spatial and temporal domains. A substantive review of the merits of the methods and covariates used to map malaria risk has not been undertaken. Therefore, this review aimed to systematically retrieve, summarise methods and examine covariates that have been used for mapping malaria risk in sub-Saharan Africa (SSA). Methods A systematic search of malaria risk mapping studies was conducted using PubMed, EBSCOhost, Web of Science and Scopus databases. The search was restricted to refereed studies published in English from January 1968 to April 2020. To ensure completeness, a manual search through the reference lists of selected studies was also undertaken. Two independent reviewers completed each of the review phases namely: identification of relevant studies based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, data extraction and methodological quality assessment using a validated scoring criterion. Results One hundred and seven studies met the inclusion criteria. The median quality score across studies was 12/16 (range: 7–16). Approximately half (44%) of the studies employed variable selection techniques prior to mapping with rainfall and temperature selected in over 50% of the studies. Malaria incidence (47%) and prevalence (35%) were the most commonly mapped outcomes, with Bayesian geostatistical models often (31%) the preferred approach to risk mapping. Additionally, 29% of the studies employed various spatial clustering methods to explore the geographical variation of malaria patterns, with Kulldorf scan statistic being the most common. Model validation was specified in 53 (50%) studies, with partitioning data into training and validation sets being the common approach. Conclusions Our review highlights the methodological diversity prominent in malaria risk mapping across SSA. To ensure reproducibility and quality science, best practices and transparent approaches should be adopted when selecting the statistical framework and covariates for malaria risk mapping. Findings underscore the need to periodically assess methods and covariates used in malaria risk mapping; to accommodate changes in data availability, data quality and innovation in statistical methodology.
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Affiliation(s)
| | - Chester Kalinda
- Discipline of Public Health Medicine, University of KwaZulu-Natal, Durban, South Africa.,Faculty of Agriculture and Natural Resources, University of Namibia, Windhoek, Namibia
| | - Peter M Macharia
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Robert W Snow
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Benn Sartorius
- Discipline of Public Health Medicine, University of KwaZulu-Natal, Durban, South Africa.,Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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20
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Addy JW, Bediako Y, Ndungu FM, Valetta JJ, Reid AJ, Mwacharo J, Ngoi JM, Wambua J, Otieno E, Musyoki J, Said K, Berriman M, Marsh K, Bejon P, Recker M, Langhorne J. 10-year longitudinal study of malaria in children: Insights into acquisition and maintenance of naturally acquired immunity. Wellcome Open Res 2021; 6:79. [PMID: 35141425 PMCID: PMC8822141 DOI: 10.12688/wellcomeopenres.16562.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2021] [Indexed: 01/26/2023] Open
Abstract
Background: Studies of long-term malaria cohorts have provided essential insights into how Plasmodium falciparum interacts with humans, and influences the development of antimalarial immunity. Immunity to malaria is acquired gradually after multiple infections, some of which present with clinical symptoms. However, there is considerable variation in the number of clinical episodes experienced by children of the same age within the same cohort. Understanding this variation in clinical symptoms and how it relates to the development of naturally acquired immunity is crucial in identifying how and when some children stop experiencing further malaria episodes. Where variability in clinical episodes may result from different rates of acquisition of immunity, or from variable exposure to the parasite. Methods: Using data from a longitudinal cohort of children residing in an area of moderate P. falciparum transmission in Kilifi district, Kenya, we fitted cumulative episode curves as monotonic-increasing splines, to 56 children under surveillance for malaria from the age of 5 to 15. Results: There was large variability in the accumulation of numbers of clinical malaria episodes experienced by the children, despite being of similar age and living in the same general location. One group of children from a particular sub-region of the cohort stopped accumulating clinical malaria episodes earlier than other children in the study. Despite lack of further clinical episodes of malaria, these children had higher asymptomatic parasite densities and higher antibody titres to a panel of P. falciparum blood-stage antigens. Conclusions: This suggests development of clinical immunity rather than lack of exposure to the parasite, and supports the view that this immunity to malaria disease is maintained by a greater exposure to P. falciparum, and thus higher parasite burdens. Our study illustrates the complexity of anti-malaria immunity and underscores the need for analyses which can sufficiently reflect the heterogeneity within endemic populations.
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Affiliation(s)
- John W.G. Addy
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
| | - Yaw Bediako
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | | | - John Joseph Valetta
- School of Mathematics and Statistics, University of St Andrews, St Andrews, UK
| | - Adam J. Reid
- Parasite Genomics, Wellcome Sanger Institute, Hixton, UK
| | | | | | - Joshua Wambua
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Edward Otieno
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Khadija Said
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Kevin Marsh
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Philip Bejon
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mario Recker
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Jean Langhorne
- Malaria Immunology Laboratory, Francis Crick Institute, London, UK
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21
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Co-Therapy of Albendazole and Dexamethasone Reduces Pathological Changes in the Cerebral Parenchyma of Th-1 and Th-2 Dominant Mice Heavily Infected with Angiostrongylus cantonensis: Histopathological and RNA-seq Analyses. Biomolecules 2021; 11:biom11040536. [PMID: 33917604 PMCID: PMC8067505 DOI: 10.3390/biom11040536] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/25/2021] [Accepted: 04/02/2021] [Indexed: 11/24/2022] Open
Abstract
Administration of albendazole alone was not very suitable for the treatment of cerebral angiostrongyliasis. This study was designed to evaluate the effects of the co-therapy of this drug and dexamethasone in Th-1 and Th-2 dominant mice infected with Angiostrongylus cantonensis. Each of BALB/c and C57BL/6 mice infected with 50 A. cantonensis third-stage larvae were administered albendazole (10 mg/kg/day) alone, dexamethasone (0.5 mg/kg/day) alone, or co-therapy of the two drugs from day 7 or 14 post-infection for 7 or 14 days. After sacrifice, coronal slices were prepared from five brain regions and stained with hematoxylin and eosin. Eight pathological changes were employed to determine the therapeutic effectiveness using a scoring system. RNA-seq analysis was performed to confirm the histopathological findings. The infected BALB/c and C57BL/6 mice had similar patterns in the pathological changes. Meningitis, hemorrhage, size of worms, and encephalitis in the cerebral parenchyma were slighter in the mice treated with co-therapy than the remaining groups. Mice treated from day 14 had more severe changes than those from day 7. The histopathological findings were found to be consistent to immune responses determined by RNA-seq analysis. Co-therapy was determined to reduce pathological changes after administration to mice infected with A. cantonensis.
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22
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Bharti AR, McCutchan JA, Umlauf A, Okwuegbuna OK, Letendre S, Cherner M, Burdo T, Jumare J, Williams K, Blattner W, Royal W. Asymptomatic Malaria Co-infection of HIV-Infected Adults in Nigeria: Prevalence of and Impact on Cognition, Mood, and Biomarkers of Systemic Inflammation. J Acquir Immune Defic Syndr 2021; 86:91-97. [PMID: 33021552 PMCID: PMC10742372 DOI: 10.1097/qai.0000000000002516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND HIV and malaria are associated with immunological perturbations and neurocognitive disorders even when asymptomatic. However, the effect of asymptomatic malaria (AM) in HIV-infected adults on neurocognitive impairment (NCI) is not well understood. This study investigated the biomarkers of systemic inflammation and neurocognition in dually infected Nigerian adults. METHODS We assessed the HIV and AM status of 269 adults and measured their global and domain-specific neurocognition and depression using standardized measures. Blood levels of sCD14 and sCD163 were also measured. RESULTS The mean age of the participants (n = 269) was 33 years, 62% were women, and AM among HIV+ and HIV- was similar (36% versus 37%). NCI was found in 23% (62/269) of participants. HIV+/AM+ had a higher prevalence of impaired learning and executive functions and were more depressed than HIV-/AM- or HIV+/AM-. HIV+ with CD4 T-cell counts ≤200/µL were more impaired in the learning domain than those with >200/µL. HIV+/AM+ group had higher levels of sCD14 compared to the other 3 groups and higher levels of sCD163 than the HIV-/AM- group. Higher levels of sCD14 and sCD163 were each associated with NCI. The sCD163 (log10) levels were higher for those with 1+ versus 2+ parasitemia level. CONCLUSIONS HIV and AM coinfection was associated with an increased risk of reduced learning and executive functions, and elevated systemic inflammation. Mood was more depressed in HIV patients with than those without AM. The mechanisms and long-term effects on neurocognition and depression among HIV+/AM+ individuals should be studied because this coinfection is common globally.
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Affiliation(s)
- Ajay R. Bharti
- University of California San Diego, School of Medicine, San Diego, CA
| | | | - Anya Umlauf
- University of California San Diego, School of Medicine, San Diego, CA
| | | | - Scott Letendre
- University of California San Diego, School of Medicine, San Diego, CA
| | - Mariana Cherner
- University of California San Diego, School of Medicine, San Diego, CA
| | - Tricia Burdo
- Temple University, Lewis Katz School of Medicine, Philadelphia, PA
| | - Jibreel Jumare
- University of Maryland, School of Medicine, Baltimore, MD
| | | | | | - Walter Royal
- University of Maryland, School of Medicine, Baltimore, MD
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA
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23
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Frimpong A, Amponsah J, Adjokatseh AS, Agyemang D, Bentum-Ennin L, Ofori EA, Kyei-Baafour E, Akyea-Mensah K, Adu B, Mensah GI, Amoah LE, Kusi KA. Asymptomatic Malaria Infection Is Maintained by a Balanced Pro- and Anti-inflammatory Response. Front Microbiol 2020; 11:559255. [PMID: 33281757 PMCID: PMC7705202 DOI: 10.3389/fmicb.2020.559255] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/19/2020] [Indexed: 01/12/2023] Open
Abstract
Background Pro- and anti-inflammatory cytokines are important mediators of immunity and are associated with malaria disease outcomes. However, their role in the establishment of asymptomatic infections, which may precede the development of clinical symptoms, is not as well-understood. Methods We determined the association of pro and anti-inflammatory cytokines and other immune effector molecules with the development of asymptomatic malaria. We measured and compared the plasma levels of pro-inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukin (IL)-6, IL-12p70, IL-17A, and granzyme B, the anti-inflammatory cytokine IL-4 and the regulatory cytokine IL-10 from children with asymptomatic malaria infections (either microscopic or submicroscopic) and uninfected controls using Luminex. Results We show that individuals with microscopic asymptomatic malaria had significantly increased levels of TNF-α and IL-6 compared to uninfected controls. Children with either microscopic or submicroscopic asymptomatic malaria exhibited higher levels of IFN-γ, IL-17A, and IL-4 compared to uninfected controls. The levels of most of the pro and anti-inflammatory cytokines were comparable between children with microscopic and submicroscopic infections. The ratio of IFN-γ/IL-10, TNF-α/IL-10, IL-6/IL-10 as well as IFN-γ/IL-4 and IL-6/IL-4 did not differ significantly between the groups. Additionally, using a principal component analysis, the cytokines measured could not distinguish amongst the three study populations. This may imply that neither microscopic nor submicroscopic asymptomatic infections were polarized toward a pro-inflammatory or anti-inflammatory response. Conclusion The data show that asymptomatic malaria infections result in increased plasma levels of both pro and anti-inflammatory cytokines relative to uninfected persons. The balance between pro- and anti-inflammatory cytokines are, however, largely maintained and this may in part, explain the lack of clinical symptoms. This is consistent with the generally accepted observation that clinical symptoms develop as a result of immunopathology involving dysregulation of inflammatory mediator balance in favor of pro-inflammatory mediators.
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Affiliation(s)
- Augustina Frimpong
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana.,Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.,African Institute for Mathematical Sciences, Accra, Ghana
| | - Jones Amponsah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Abigail Sena Adjokatseh
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Dorothy Agyemang
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Lutterodt Bentum-Ennin
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Ebenezer Addo Ofori
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana.,Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Eric Kyei-Baafour
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Kwadwo Akyea-Mensah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Bright Adu
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Gloria Ivy Mensah
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Linda Eva Amoah
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana.,Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Kwadwo Asamoah Kusi
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana.,Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.,Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
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24
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Nonlethal Plasmodium yoelii Infection Drives Complex Patterns of Th2-Type Host Immunity and Mast Cell-Dependent Bacteremia. Infect Immun 2020; 88:IAI.00427-20. [PMID: 32958528 PMCID: PMC7671899 DOI: 10.1128/iai.00427-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/16/2020] [Indexed: 12/11/2022] Open
Abstract
Malaria strongly predisposes to bacteremia, which is associated with sequestration of parasitized red blood cells and increased gastrointestinal permeability. The mechanisms underlying this disruption are poorly understood. Here, we evaluated the expression of factors associated with mast cell activation and malaria-associated bacteremia in a rodent model. C57BL/6J mice were infected with Plasmodium yoeliiyoelli 17XNL, and blood and tissues were collected over time to assay for circulating levels of bacterial 16S DNA, IgE, mast cell protease 1 (Mcpt-1) and Mcpt-4, Th1 and Th2 cytokines, and patterns of ileal mastocytosis and intestinal permeability. Malaria strongly predisposes to bacteremia, which is associated with sequestration of parasitized red blood cells and increased gastrointestinal permeability. The mechanisms underlying this disruption are poorly understood. Here, we evaluated the expression of factors associated with mast cell activation and malaria-associated bacteremia in a rodent model. C57BL/6J mice were infected with Plasmodium yoeliiyoelli 17XNL, and blood and tissues were collected over time to assay for circulating levels of bacterial 16S DNA, IgE, mast cell protease 1 (Mcpt-1) and Mcpt-4, Th1 and Th2 cytokines, and patterns of ileal mastocytosis and intestinal permeability. The anti-inflammatory cytokines (interleukin-4 [IL-4], IL-6, and IL-10) and MCP-1/CCL2 were detected early after P. yoeliiyoelii 17XNL infection. This was followed by the appearance of IL-9 and IL-13, cytokines known for their roles in mast cell activation and growth-enhancing activity as well as IgE production. Later increases in circulating IgE, which can induce mast cell degranulation, as well as Mcpt-1 and Mcpt-4, were observed concurrently with bacteremia and increased intestinal permeability. These results suggest that P. yoeliiyoelii 17XNL infection induces the production of early cytokines that activate mast cells and drive IgE production, followed by elevated IgE, IL-9, and IL-13 that maintain and enhance mast cell activation while disrupting the protease/antiprotease balance in the intestine, contributing to epithelial damage and increased permeability.
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25
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Andrade CM, Fleckenstein H, Thomson-Luque R, Doumbo S, Lima NF, Anderson C, Hibbert J, Hopp CS, Tran TM, Li S, Niangaly M, Cisse H, Doumtabe D, Skinner J, Sturdevant D, Ricklefs S, Virtaneva K, Asghar M, Homann MV, Turner L, Martins J, Allman EL, N'Dri ME, Winkler V, Llinás M, Lavazec C, Martens C, Färnert A, Kayentao K, Ongoiba A, Lavstsen T, Osório NS, Otto TD, Recker M, Traore B, Crompton PD, Portugal S. Increased circulation time of Plasmodium falciparum underlies persistent asymptomatic infection in the dry season. Nat Med 2020; 26:1929-1940. [PMID: 33106664 DOI: 10.1038/s41591-020-1084-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 08/27/2020] [Indexed: 12/25/2022]
Abstract
The dry season is a major challenge for Plasmodium falciparum parasites in many malaria endemic regions, where water availability limits mosquito vectors to only part of the year. How P. falciparum bridges two transmission seasons months apart, without being cleared by the human host or compromising host survival, is poorly understood. Here we show that low levels of P. falciparum parasites persist in the blood of asymptomatic Malian individuals during the 5- to 6-month dry season, rarely causing symptoms and minimally affecting the host immune response. Parasites isolated during the dry season are transcriptionally distinct from those of individuals with febrile malaria in the transmission season, coinciding with longer circulation within each replicative cycle of parasitized erythrocytes without adhering to the vascular endothelium. Low parasite levels during the dry season are not due to impaired replication but rather to increased splenic clearance of longer-circulating infected erythrocytes, which likely maintain parasitemias below clinical and immunological radar. We propose that P. falciparum virulence in areas of seasonal malaria transmission is regulated so that the parasite decreases its endothelial binding capacity, allowing increased splenic clearance and enabling several months of subclinical parasite persistence.
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Affiliation(s)
- Carolina M Andrade
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Hannah Fleckenstein
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Richard Thomson-Luque
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Safiatou Doumbo
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Nathalia F Lima
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Carrie Anderson
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Julia Hibbert
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Christine S Hopp
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Tuan M Tran
- Division of Infectious Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Shanping Li
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Moussa Niangaly
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Hamidou Cisse
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Didier Doumtabe
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Jeff Skinner
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Dan Sturdevant
- Rocky Mountain Laboratory Research Technologies Section, Genomics Unit, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Stacy Ricklefs
- Rocky Mountain Laboratory Research Technologies Section, Genomics Unit, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Kimmo Virtaneva
- Rocky Mountain Laboratory Research Technologies Section, Genomics Unit, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Muhammad Asghar
- Department of Medicine Solna, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden.,Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Manijeh Vafa Homann
- Department of Medicine Solna, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden.,Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Louise Turner
- Department of Immunology and Microbiology, Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, København N, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Joana Martins
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Portugal and ICVS/3B's -PT Government Associate Laboratory, Braga, Portugal
| | - Erik L Allman
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, State College, PA, USA
| | | | - Volker Winkler
- Institute of Global Health, Heidelberg University Hospital, Heidelberg, Germany
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, State College, PA, USA.,Department of Chemistry, The Pennsylvania State University, State College, PA, USA
| | | | - Craig Martens
- Rocky Mountain Laboratory Research Technologies Section, Genomics Unit, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Anna Färnert
- Department of Medicine Solna, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden.,Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Kassoum Kayentao
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Aissata Ongoiba
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Thomas Lavstsen
- Department of Immunology and Microbiology, Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, København N, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Nuno S Osório
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Portugal and ICVS/3B's -PT Government Associate Laboratory, Braga, Portugal
| | - Thomas D Otto
- Institute of Infection, Immunity & Inflammation, MVLS, University of Glasgow, Glasgow, UK
| | - Mario Recker
- Centre for Mathematics & the Environment, University of Exeter, Penryn Campus, Penryn, UK
| | - Boubacar Traore
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Peter D Crompton
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Silvia Portugal
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany. .,German Center for Infection Research (DZIF), Heidelberg, Heidelberg, Germany. .,Max Planck Institute for Infection Biology, Berlin, Germany.
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