101
|
Guerra RI, Ore M, Valdivia HO, Bishop DK, Ramos M, Mores CN, Campbell WR. A cluster of the first reported Plasmodium ovale spp. infections in Peru occuring among returning UN peace-keepers, a review of epidemiology, prevention and diagnostic challenges in nonendemic regions. Malar J 2019; 18:176. [PMID: 31113437 PMCID: PMC6530030 DOI: 10.1186/s12936-019-2809-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/13/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Plasmodium ovale curtisi and Plasmodium ovale wallikeri are regarded as less virulent forms of malaria with a geographic distribution including Southeast Asia, Central and West Africa, and is increasingly reported as an infection in returning travellers. A species of malaria that may have delayed or relapsing presentations similar to Plasmodium vivax, the clinical presentation of P. ovale spp. has been described to have prepatent periods of 2 weeks or slightly longer with reports of relapse following primary infection out to 8-9 months. This presentation may be obscured further in the setting of anti-malarial exposure, with report of delayed primary infection out to 4 years. Presented is a cluster of 4 imported P. ovale spp. cases in returning Peruvian military personnel assigned to United Nations peace-keeping operations in the Central African Republic. CASE PRESENTATION From January to December 2016, Peruvian peace-keepers were deployed in support of United Nations (UN) operations in the Central African Republic (CAR). While serving abroad, Navy, Army, and Air Force members experienced 223 episodes of Plasmodium falciparum malaria following interruption of prophylaxis with mefloquine. Diagnosis was made using rapid diagnostics tests (RDTs) and/or smear with no coinfections identified. Cases of malaria were treated with locally-procured artemether-lumefantrine. Returning to Peru in January 2017, 200 peace-keepers were screened via thick and thin smear while on weekly mefloquine prophylaxis with only 1 showing nucleic acid within red blood cells consistent with Plasmodium spp. and 11 reporting syndromes of ill-defined somatic complaints. Between a period of 5 days to 11 months post return, 4 cases of P. ovale spp. were diagnosed using smear and polymerase chain reaction (PCR) following febrile complaints. All cases were subsequently treated with chloroquine and primaquine, with cure of clinical disease and documented clearance of parasitaemia. CONCLUSION These patients represent the first imported cases in Peru of this species of malaria as well as highlight the challenges in implementing population level prophylaxis in a deployed environment, and the steps for timely diagnosis and management in a non-endemic region where risk of introduction for local transmission exists.
Collapse
Affiliation(s)
| | | | | | | | | | - Christopher N Mores
- U.S. Naval Medical Research Unit No. 6, Lima, Peru
- Department of Global Health, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA
| | - Wesley R Campbell
- U.S. Naval Medical Research Unit No. 6, Lima, Peru.
- Division of Infectious Diseases, Department of Internal Medicine, Walter Reed National Military Medical Center, Bethesda, MD, USA.
| |
Collapse
|
102
|
Cheviet T, Lefebvre-Tournier I, Wein S, Peyrottes S. Plasmodium Purine Metabolism and Its Inhibition by Nucleoside and Nucleotide Analogues. J Med Chem 2019; 62:8365-8391. [PMID: 30964283 DOI: 10.1021/acs.jmedchem.9b00182] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Malaria still affects around 200 million people and is responsible for more than 400,000 deaths per year, mostly children in subequatorial areas. This disease is caused by parasites of the Plasmodium genus. Only a few WHO-recommended treatments are available to prevent or cure plasmodial infections, but genetic mutations in the causal parasites have led to onset of resistance against all commercial antimalarial drugs. New drugs and targets are being investigated to cope with this emerging problem, including enzymes belonging to the main metabolic pathways, while nucleoside and nucleotide analogues are also a promising class of potential drugs. This review highlights the main metabolic pathways targeted for the development of potential antiplasmodial therapies based on nucleos(t)ide analogues, as well as the different series of purine-containing nucleoside and nucleotide derivatives designed to inhibit Plasmodium falciparum purine metabolism.
Collapse
Affiliation(s)
- Thomas Cheviet
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 UM-CNRS-ENSCM , Université Montpellier, Equipe Nucléosides & Effecteurs Phosphorylés , Place E. Bataillon, cc 1704 , 34095 Montpellier , France
| | - Isabelle Lefebvre-Tournier
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 UM-CNRS-ENSCM , Université Montpellier, Equipe Nucléosides & Effecteurs Phosphorylés , Place E. Bataillon, cc 1704 , 34095 Montpellier , France
| | - Sharon Wein
- Dynamique des Interactions Membranaires Normales et Pathologiques (DIMNP), UMR 5235 UM-CNRS , Université Montpellier , Place E. Bataillon , 34095 Montpellier , France
| | - Suzanne Peyrottes
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 UM-CNRS-ENSCM , Université Montpellier, Equipe Nucléosides & Effecteurs Phosphorylés , Place E. Bataillon, cc 1704 , 34095 Montpellier , France
| |
Collapse
|
103
|
Zhang X, Chu R, Xu S, Fu H, Tang J, Chen L, Shi X, Chen J, Li Y, Zhu G, Han ET, Xuan Y, Cao J, Cheng Y. Immunogenicity analysis of genetically conserved segments in Plasmodium ovale merozoite surface protein-8. Parasit Vectors 2019; 12:164. [PMID: 30975200 PMCID: PMC6460738 DOI: 10.1186/s13071-019-3412-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 03/26/2019] [Indexed: 12/02/2022] Open
Abstract
Background Plasmodium ovale is widely distributed across tropical regions and has two closely related but distinct species, namely P. ovale curtisi and P. ovale wallikeri. Combining genetic characterization with the immunogenicity of merozoite surface protein-8 (MSP-8) supports considering MSP-8 as a candidate target for blood-stage vaccines against malaria. However, no previous studies have focused on characterizing the genetic diversity and immunogenicity of PoMSP-8. Methods Blood samples were collected from 42 patients infected with P. ovale. The patients were migrant workers returning to the Jiangsu Province from Africa; genomic DNA was extracted from their blood samples for sequencing and protein expression. The recombinant PoMSP-8 (rPoMSP-8) proteins were expressed and purified to assess their immune responses in BALB/c mice. Results The sequences of the P. ovale curtisi and P. ovale wallikeri msp8 genes were completely conserved in each isolate. The rPoMSP-8 proteins were successfully expressed and purified as ~70 kDa proteins. Antibodies raised against rPoMSP-8 in mice showed appropriate immunoreactivity, as evidenced by immunoblotting. These specific antibodies were detected at day 7 post-immunization, and their levels increased throughout the whole immunization period. rPoMSP-8-raised antibodies had high endpoint titers (1:5,120,000) and high avidity (PocMSP-8: 94.84%, PowMSP-8: 92.69%). Cross-reactivity between rPocMSP-8 and rPowMSP-8 was observed with each anti-PoMSP8-specific antibody. Conclusions Remarkable conservation and high immunogenicity was observed in both rPoMSP-8s. Intriguingly, cross-reaction between rPocMSP-8 and rPowMSP-8 was detected, suggesting that a single PoMSP8-based construction might be applicable for both species. Electronic supplementary material The online version of this article (10.1186/s13071-019-3412-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Xinxin Zhang
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Ruilin Chu
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Sui Xu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, Jiangsu, People's Republic of China
| | - Haitian Fu
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Jianxia Tang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, Jiangsu, People's Republic of China
| | - Limei Chen
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Xiaodan Shi
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Jing Chen
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, Jiangsu, People's Republic of China
| | - Yuhong Li
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Guoding Zhu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, Jiangsu, People's Republic of China
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Yinghua Xuan
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.
| | - Jun Cao
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China. .,Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, Jiangsu, People's Republic of China.
| | - Yang Cheng
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.
| |
Collapse
|
104
|
Lamien-Meda A, Fuehrer HP, Noedl H. Novel high resolution melting (HRM) and snapback assays for simultaneous detection and differentiation of Plasmodium ovale spp. Acta Trop 2019; 192:75-81. [PMID: 30711423 DOI: 10.1016/j.actatropica.2019.01.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 01/18/2019] [Accepted: 01/18/2019] [Indexed: 12/16/2022]
Abstract
Plasmodium ovale spp. are two of the six species of apicomplexan parasites belonging to the genus Plasmodium commonly causing disease in humans. A recent phylogeny study has identified both Plasmodium ovale species (P. ovale curtisi and P. ovale wallikeri) as two sympatric occurring species. The actual prevalence and clinical relevance of P. ovale spp. are likely underestimated due to low parasitemia and mixed infections, which pose a major challenge to microscopic diagnosis and are frequently undetectable using malaria Rapid Diagnostic Tests (RDTs). The aim of this work is to develop a HRM-based assay for simultaneous detection and differentiation of P. ovale wallikeri and P. ovale curtisi. Thirty three well-documented P. ovale spp. samples from previous studies were used for this study. The newly developed High Resolution Melting (HRM) assay targeting the apicoplast genome was highly specific to both P. ovale species. Adding a snapback tail at the 5' end of the forward primer for a nested HRM PCR, increased the melting temperature (Tm) difference between the two species. To our knowledge this study reports the first direct HRM assay developed on the apicoplast genome, specific for both P. ovale species. This method provides added value to the WHO open request of developing new practical malaria diagnostic methods for the malaria elimination program and could contribute to a quick and efficient diagnosis of low-level parasitemia, symptomatic or asymptomatic, as well as mixed or single P. ovale infections.
Collapse
Affiliation(s)
- Aline Lamien-Meda
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Austria.
| | - Hans-Peter Fuehrer
- Institute of Parasitology, University of Veterinary Medicine, Vienna, Austria
| | - Harald Noedl
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Austria
| |
Collapse
|
105
|
Sun H, Li J, Xu C, Xiao T, Wang L, Kong X, Wang Y, Zhang B, Zhao C, Huang B, Wei Q. Increasing number of imported Plasmodium ovale wallikeri malaria in Shandong Province, China, 2015-2017. Acta Trop 2019; 191:248-251. [PMID: 30659805 DOI: 10.1016/j.actatropica.2019.01.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/15/2019] [Accepted: 01/15/2019] [Indexed: 10/27/2022]
Abstract
Since 2012, no indigenous malaria case have been reported in Shandong Province, China, whereas the number of imported cases and the genetic diversity of Plasmodium spp. have increased. Beginning in 2015, the number of Plasmodium ovale cases were increased and the P. ovale wallikeri malaria case began to arise. From 2015 to 2017, a total of 676 imported malaria cases were detected and 76 P. ovale spp. isolates were identified, of which 48 were P. ovale curtisi and 28 P. ovale wallikeri. The number of P. ovale wallikeri malaria cases increased yearly, six were identified in 2015, eight were identified in 2016, and 14 were identified in 2017. All cases with an attached travel history from Africa, with represented source countries of Equatorial Guinea (n = 9), Republic of the Congo (n = 4), and Democratic Republic of the Congo (n = 3). P. ovale wallikeri is increasing among travelers returning to Shandong Province from Africa. Although the P. ovale spp. infection rarely progressed to severity, this species is suspected to generate hypnozoites which have the potential to relapse. The ability to cause relapse is the threat to public health and should be concerned.
Collapse
|
106
|
Characterization of Plasmodium ovale spp. imported from Africa to Henan Province, China. Sci Rep 2019; 9:2191. [PMID: 30778106 PMCID: PMC6379410 DOI: 10.1038/s41598-019-38629-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 01/04/2019] [Indexed: 01/19/2023] Open
Abstract
As indigenous malaria has decreased over recent decades, the increasing number of imported malaria cases has provided a new challenge for China. The proportion of imported cases due to Plasmodium ovale has increased during this time, and the difference between P. ovale curtisi and P. ovale wallikeri is of importance. To better understand P. ovale epidemiology and the differences between the two subspecies, information on imported malaria in Henan Province was collected during 2010–2017. We carried out a descriptive study to analyze the prevalence, proportion, distribution, and origin of P. o. curtisi and P. o. wallikeri. It showed that imported P. ovale spp. accounts for a large proportion of total malaria cases in Henan Province, even more than that of P. vivax. This suggests that the proportion of P. ovale cases is underestimated in Africa. Among these cases, the latency period of P. o. curtisi was significantly longer than that of P. o. wallikeri. More attention should be paid to imported ovale malaria to avoid the reintroduction of these two subspecies into China.
Collapse
|
107
|
Pacheco MA, Matta NE, Valkiunas G, Parker PG, Mello B, Stanley CE, Lentino M, Garcia-Amado MA, Cranfield M, Kosakovsky Pond SL, Escalante AA. Mode and Rate of Evolution of Haemosporidian Mitochondrial Genomes: Timing the Radiation of Avian Parasites. Mol Biol Evol 2019; 35:383-403. [PMID: 29126122 PMCID: PMC5850713 DOI: 10.1093/molbev/msx285] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Haemosporidians are a diverse group of vector-borne parasitic protozoa that includes the agents of human malaria; however, most of the described species are found in birds and reptiles. Although our understanding of these parasites’ diversity has expanded by analyses of their mitochondrial genes, there is limited information on these genes’ evolutionary rates. Here, 114 mitochondrial genomes (mtDNA) were studied from species belonging to four genera: Leucocytozoon, Haemoproteus, Hepatocystis, and Plasmodium. Contrary to previous assertions, the mtDNA is phylogenetically informative. The inferred phylogeny showed that, like the genus Plasmodium, the Leucocytozoon and Haemoproteus genera are not monophyletic groups. Although sensitive to the assumptions of the molecular dating method used, the estimated times indicate that the diversification of the avian haemosporidian subgenera/genera took place after the Cretaceous–Paleogene boundary following the radiation of modern birds. Furthermore, parasite clade differences in mtDNA substitution rates and strength of negative selection were detected. These differences may affect the biological interpretation of mtDNA gene lineages used as a proxy to species in ecological and parasitological investigations. Given that the mitochondria are critically important in the parasite life cycle stages that take place in the vector and that the transmission of parasites belonging to particular clades has been linked to specific insect families/subfamilies, this study suggests that differences in vectors have affected the mode of evolution of haemosporidian mtDNA genes. The observed patterns also suggest that the radiation of haemosporidian parasites may be the result of community-level evolutionary processes between their vertebrate and invertebrate hosts.
Collapse
Affiliation(s)
- M Andreína Pacheco
- Department of Biology, Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, PA
| | - Nubia E Matta
- Departamento de Biología, Grupo de Investigación Caracterización Genética e Inmunología, Sede Bogotá-Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia
| | | | - Patricia G Parker
- Department of Biology, Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, St. Louis, MO
| | - Beatriz Mello
- Department of Biology, Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, PA
| | - Craig E Stanley
- Department of Biology, Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, PA
| | | | - Maria Alexandra Garcia-Amado
- Laboratorio de Fisiología Gastrointestinal, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas (IVIC), Miranda, Venezuela
| | - Michael Cranfield
- Gorilla Doctors, the Wildlife Health Center School of Veterinary Medicine, University of California, Davis, CA
| | - Sergei L Kosakovsky Pond
- Department of Biology, Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, PA
| | - Ananias A Escalante
- Department of Biology, Institute for Genomics and Evolutionary Medicine (igem), Temple University, Philadelphia, PA
| |
Collapse
|
108
|
Lu F, Ahmed MA, Xu S, Xu S, Han JH, Liu Q, Chen J, Zhu G, Zhou H, Cao J, Han ET. Plasmodium ovale curtisi and Plasmodium ovale wallikeri in Chinese travelers: Prevalence of novel genotypes of circumsporozoite protein in the African continent. INFECTION GENETICS AND EVOLUTION 2019; 70:9-14. [PMID: 30763775 DOI: 10.1016/j.meegid.2019.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 01/15/2019] [Accepted: 02/09/2019] [Indexed: 10/27/2022]
Abstract
Imported malaria due to Plasmodium ovale curtisi and P. ovale wallikeri infections from African countries has increased recently (2011-2014) in Chinese travelers. We report novel genotypes, their prevalence and the predominant haplotypes of P. ovale curtisi and P. ovale wallikeri circumsporozoite protein (CSP) from 20 African countries in Chinese travelers. These genotypes should be considered while designing a CSP-based vaccine against P. ovale malaria.
Collapse
Affiliation(s)
- Feng Lu
- Department of Parasitology, Institute of Translational Medicine, Medical College, Yangzhou University, Jiangsu Key Laboratory of Experimental & Translational Non-coding RNA Research, Yangzhou 225001, Jiangsu Province, People's Republic of China; Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, Jiangsu Province, People's Republic of China
| | - Md Atique Ahmed
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 24341, Republic of Korea
| | - Simin Xu
- Department of Parasitology, Institute of Translational Medicine, Medical College, Yangzhou University, Jiangsu Key Laboratory of Experimental & Translational Non-coding RNA Research, Yangzhou 225001, Jiangsu Province, People's Republic of China
| | - Sui Xu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, Jiangsu Province, People's Republic of China
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 24341, Republic of Korea
| | - Qianyan Liu
- Department of Parasitology, Institute of Translational Medicine, Medical College, Yangzhou University, Jiangsu Key Laboratory of Experimental & Translational Non-coding RNA Research, Yangzhou 225001, Jiangsu Province, People's Republic of China
| | - Jing Chen
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, Jiangsu Province, People's Republic of China
| | - Guoding Zhu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, Jiangsu Province, People's Republic of China
| | - Huayun Zhou
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, Jiangsu Province, People's Republic of China
| | - Jun Cao
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, Jiangsu Province, People's Republic of China.
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 24341, Republic of Korea.
| |
Collapse
|
109
|
Garrido-Cardenas JA, Manzano-Agugliaro F, González-Cerón L, Gil-Montoya F, Alcayde-Garcia A, Novas N, Mesa-Valle C. The Identification of Scientific Communities and Their Approach to Worldwide Malaria Research. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15122703. [PMID: 30513616 PMCID: PMC6313382 DOI: 10.3390/ijerph15122703] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 12/20/2022]
Abstract
It is essential to establish a pattern to detect the strengths and weaknesses of working groups publishing on malaria, to promote coordination to facilitate the eradication of the disease. Given the complexity of the scientific network of groups and institutions studying malaria, it is necessary to use a mathematical algorithm that allows us to know the real structure of research on the disease in the world. In this work, articles with the word “malaria” in the title or author keywords gathered from Elsevier Scopus database were analyzed. By means of specific software, graphs were created. The analysis of the data allowed established different scientific communities, among which two were very diverse: one formed by those groups concerned about the vector transmission and control, and another one focused on the drug resistance of the parasite. Basic, applied, and operational research to eradicate malaria is an ambitious goal of the international institutions and the scientific community. The combination of effort and the establishment of a worldwide-scientific network that allows an effective interconnection (exchange) of knowledge, infrastructure technology, collaborators, financial resources, and datasets will contribute more effectively to end the disease.
Collapse
Affiliation(s)
| | | | - Lilia González-Cerón
- Regional Center for Public Health Research, National Institute of Public Health, Tapachula 30700, Chiapas, Mexico.
| | | | | | - Nuria Novas
- Department of Engineering, University of Almeria, CeiA3. 04120 Almeria, Spain.
| | | |
Collapse
|
110
|
Nabarro LEB, Nolder D, Broderick C, Nadjm B, Smith V, Blaze M, Checkley AM, Chiodini PL, Sutherland CJ, Whitty CJM. Geographical and temporal trends and seasonal relapse in Plasmodium ovale spp. and Plasmodium malariae infections imported to the UK between 1987 and 2015. BMC Med 2018; 16:218. [PMID: 30477484 PMCID: PMC6260574 DOI: 10.1186/s12916-018-1204-6] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/31/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium ovale spp. and P. malariae cause illness in endemic regions and returning travellers. Far less is known about these species than P. falciparum and P. vivax. METHODS The UK national surveillance data, collected 1987 to 2015, were collated with the International Passenger Survey and climatic data to determine geographical, temporal and seasonal trends of imported P. ovale spp. and P. malariae infection. RESULTS Of 52,242 notified cases of malaria, 6.04% (3157) were caused by P. ovale spp. and 1.61% (841) by P. malariae; mortality was 0.03% (1) and 0.12% (1), respectively. Almost all travellers acquired infection in West or East Africa. Infection rate per travel episode fell fivefold during the study period. The median latency of P. malariae and P. ovale spp. was 18 and 76 days, respectively; delayed presentation occurred with both species. The latency of P. ovale spp. infection imported from West Africa was significantly shorter in those arriving in the UK during the West African peak malarial season compared to those arriving outside it (44 days vs 94 days, p < 0.0001), implying that relapse synchronises with the period of high malarial transmission. This trend was not seen in P. ovale spp. imported from East Africa nor in P. malariae. CONCLUSION In West Africa, where malaria transmission is highly seasonal, P. ovale spp. may have evolved to relapse during the malarial high transmission season. This has public health implications. Deaths are very rare, supporting current guidelines emphasising outpatient treatment. However, late presentations do occur.
Collapse
Affiliation(s)
- Laura E B Nabarro
- Public Health England Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Debbie Nolder
- Public Health England Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Claire Broderick
- The Hospital for Tropical Diseases, Mortimer Market Capper Street, London, WC1E 6JD, UK
| | - Behzad Nadjm
- The Hospital for Tropical Diseases, Mortimer Market Capper Street, London, WC1E 6JD, UK.,Oxford University Clinical Research Unit, Hanoi, Vietnam
| | - Valerie Smith
- Public Health England Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Marie Blaze
- Public Health England Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Anna M Checkley
- The Hospital for Tropical Diseases, Mortimer Market Capper Street, London, WC1E 6JD, UK
| | - Peter L Chiodini
- Public Health England Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.,The Hospital for Tropical Diseases, Mortimer Market Capper Street, London, WC1E 6JD, UK
| | - Colin J Sutherland
- Public Health England Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Christopher J M Whitty
- Public Health England Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.,The Hospital for Tropical Diseases, Mortimer Market Capper Street, London, WC1E 6JD, UK
| |
Collapse
|
111
|
Wilcox JJS, Kerschner A, Hollocher H. WITHDRAWN: Indel-informed bayesian analysis suggests cryptic divisions between Plasmodium knowlesi of humans and long-tailed macaques (Macaca fascicularis) in Malaysian Borneo. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2018:S1567-1348(18)30557-4. [PMID: 30481580 DOI: 10.1016/j.meegid.2018.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/24/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.
Collapse
Affiliation(s)
- Justin J S Wilcox
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556-5688, USA.
| | - Abigail Kerschner
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556-5688, USA
| | - Hope Hollocher
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556-5688, USA
| |
Collapse
|
112
|
Chu R, Zhang X, Xu S, Chen L, Tang J, Li Y, Chen J, Xuan Y, Zhu G, Cao J, Cheng Y. Limited genetic diversity of N-terminal of merozoite surface protein-1 (MSP-1) in Plasmodium ovale curtisi and P. ovale wallikeri imported from Africa to China. Parasit Vectors 2018; 11:596. [PMID: 30446012 PMCID: PMC6240192 DOI: 10.1186/s13071-018-3174-0] [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: 07/09/2018] [Accepted: 10/25/2018] [Indexed: 11/27/2022] Open
Abstract
Background Plasmodium merozoite surface protein-1 (MSP-1) is released into the bloodstream during merozoite invasion, and thus represents a crucial malarial vaccine target. Although substantial research effort has been devoted to uncovering the genetic diversity of MSP-1 for P. falciparum and P. vivax, there is minimal information available regarding the genetic profiles and structure of P. ovale. Therefore, the aim of the present study was to determine the extent of genetic variation among two subspecies of P. ovale by characterizing the MSP-1 N-terminal sequence at the nucleotide and protein levels. Methods N-terminal of MSP-1 gene were amplified from 126 clinical samples collected from imported cases of malaria in migrant workers returning to Jiangsu Province from Africa using a conventional polymerase chain reaction (PCR) assay. The PCR products were then sequenced and analyzed using the GeneDoc, MegAlign, MEGA7 and DnaSP v.6 programs. Results The average pairwise nucleotide diversities (π) of P. ovale curtisi and P. ovale wallikeri MSP-1 genes (pomsp1) were 0.01043 and 0.01974, respectively, and the haplotype diversity (Hd) were 0.746 and 0.598, respectively. Most of the nucleotide substitutions detected were non-synonymous, indicating that the genetic variations of pomsp1 were maintained by positive diversifying selection, thereby suggesting their role as a potential target of a protective immune response. Amino acid substitutions of P. ovale curtisi and P. ovale wallikeri MSP-1 could be categorized into five and three unique amino acid variants, respectively. Conclusions Low mutational diversity was observed in pomsp1 from the Jiangsu Province imported malaria cases; further studies will be developed such as immunogenicity and functional analysis. Electronic supplementary material The online version of this article (10.1186/s13071-018-3174-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ruilin Chu
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Xinxin Zhang
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Sui Xu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Limei Chen
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Jianxia Tang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Yuhong Li
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Jing Chen
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Yinghua Xuan
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Guoding Zhu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Jun Cao
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China. .,Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasite Diseases, Wuxi, 214064, Jiangsu, People's Republic of China.
| | - Yang Cheng
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.
| |
Collapse
|
113
|
Plasmodium genomics: an approach for learning about and ending human malaria. Parasitol Res 2018; 118:1-27. [PMID: 30402656 DOI: 10.1007/s00436-018-6127-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/19/2018] [Indexed: 12/31/2022]
Abstract
Malaria causes high levels of morbidity and mortality in human beings worldwide. According to the World Health Organization (WHO), about half a million people die of this disease each year. Malaria is caused by six species of parasites belonging to the Plasmodium genus: P. falciparum, P. knowlesi, P. vivax, P. malariae, P. ovale curtisi, and P. ovale wallikeri. Currently, malaria is being kept under control with varying levels of elimination success in different countries. The development of new molecular tools as well as the use of next-generation sequencing (NGS) technologies and novel bioinformatic approaches has improved our knowledge of malarial epidemiology, diagnosis, treatment, vaccine development, and surveillance strategies. In this work, the genetics and genomics of human malarias have been analyzed. Since the first P. falciparum genome was sequenced in 2002, various population-level genetic and genomic surveys, together with transcriptomic and proteomic studies, have shown the importance of molecular approaches in supporting malaria elimination.
Collapse
|
114
|
Rojo-Marcos G, Rubio-Muñoz JM, Angheben A, Jaureguiberry S, García-Bujalance S, Tomasoni LR, Rodríguez-Valero N, Ruiz-Giardín JM, Salas-Coronas J, Cuadros-González J, García-Rodríguez M, Molina-Romero I, López-Vélez R, Gobbi F, Calderón-Moreno M, Martin-Echevarría E, Elía-López M, Llovo-Taboada J. Prospective comparative multi-centre study on imported Plasmodium ovale wallikeri and Plasmodium ovale curtisi infections. Malar J 2018; 17:399. [PMID: 30376868 PMCID: PMC6208040 DOI: 10.1186/s12936-018-2544-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/22/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Few previous retrospective studies suggest that Plasmodium ovale wallikeri seems to have a longer latency period and produces deeper thrombocytopaenia than Plasmodium ovale curtisi. Prospective studies were warranted to better assess interspecies differences. METHODS Patients with imported P. ovale spp. infection diagnosed by thick or thin film, rapid diagnostic test (RDT) or polymerase chain reaction (PCR) were recruited between March 2014 and May 2017. All were confirmed by DNA isolation and classified as P. o. curtisi or P. o. wallikeri using partial sequencing of the ssrRNA gene. Epidemiological, analytical and clinical differences were analysed by statistical methods. RESULTS A total of 79 samples (35 P. o. curtisi and 44 P. o. wallikeri) were correctly genotyped. Males predominate in wallikeri group (72.7%), whereas were 48.6% in curtisi group. Conversely, 74.3% of curtisi group were from patients of African ethnicity, whilst 52.3% of Caucasians were infected by P. o. wallikeri. After performing a multivariate analysis, more thrombocytopaenic patients (p = 0.022), a lower number of platelets (p = 0.015), a higher INR value (p = 0.041), and shorter latency in Caucasians (p = 0.034) were significantly seen in P. o. wallikeri. RDT sensitivity was 26.1% in P. o. curtisi and 42.4% in P. o. wallikeri. Nearly 20% of both species were diagnosed only by PCR. Total bilirubin over 3 mg/dL was found in three wallikeri cases. Two patients with curtisi infection had haemoglobin under 7 g/dL, one of them also with icterus. A wallikeri patient suffered from haemophagocytosis. Chemoprophylaxis failed in 14.8% and 35% of curtisi and wallikeri patients, respectively. All treated patients with various anti-malarials which included artesunate recovered. Diabetes mellitus was described in 5 patients (6.32%), 4 patients of wallikeri group and 1 curtisi. CONCLUSIONS Imported P. o. wallikeri infection may be more frequent in males and Caucasians. Malaria caused by P. o. wallikeri produces more thrombocytopaenia, a higher INR and shorter latency in Caucasians and suggests a more pathogenic species. Severe cases can be seen in both species. Chemoprophylaxis seems less effective in P. ovale spp. infection than in P. falciparum, but any anti-malarial drug is effective as initial treatment. Diabetes mellitus could be a risk factor for P. ovale spp. infection.
Collapse
Affiliation(s)
- Gerardo Rojo-Marcos
- Hospital Universitario Príncipe de Asturias, Ctra de Meco s/n, 28805, Alcalá de Henares, Madrid, Spain.
| | | | | | - Stephane Jaureguiberry
- Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris (APHP), Paris, France
| | | | | | | | | | | | - Juan Cuadros-González
- Hospital Universitario Príncipe de Asturias, Ctra de Meco s/n, 28805, Alcalá de Henares, Madrid, Spain
| | | | | | | | - Federico Gobbi
- Ospedale Sacro Cuore - Don Calabria, Negrar, Verona, Italy
| | | | | | | | - José Llovo-Taboada
- Complejo Hospitalario Universitario de Santiago de Compostela, A Coruña, Spain
| | | |
Collapse
|
115
|
Nijhuis RHT, van Lieshout L, Verweij JJ, Claas ECJ, Wessels E. Multiplex real-time PCR for diagnosing malaria in a non-endemic setting: a prospective comparison to conventional methods. Eur J Clin Microbiol Infect Dis 2018; 37:2323-2329. [PMID: 30259214 DOI: 10.1007/s10096-018-3378-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 09/06/2018] [Indexed: 11/29/2022]
Abstract
Almost a decade ago our diagnostic laboratory implemented an in-house real-time PCR for the detection of Plasmodium DNA to diagnose malaria in parallel with conventional diagnostics, i.e., microscopy (thick and thin smears), quantitative buffy coat microscopy (QBC), and a rapid diagnostic test (RDT). Here we report our experiences and make a comparison between the different diagnostic procedures used in this non-endemic setting. All patients during the period February 2009-December 2017 suspected of malaria were prospectively tested at the moment of sample collection. Both PCR and conventional malaria diagnostics were carried out on a total of 839 specimens from 825 patients. In addition, three Plasmodium falciparum (Pf) patients were closely followed by real-time PCR and microscopy after treatment. Overall, 56 samples (55 patients) tested positive by real-time PCR, of which six were missed by microscopy and seven by QBC. RDT showed fairly good results in detecting Pf, whereas specificity was not optimal. RDT failed to detect 10 of 17 non-Pf PCR positive specimens. One Plasmodium malariae patient would have been missed if only conventional diagnostic tests had been used. The high sensitivity of the PCR was confirmed by the number of PCR positive, microscopy negative post-treatment samples. In conclusion, within our routine diagnostic setting, malaria real-time PCR not only showed a high level of agreement with the conventional methods used, but also showed higher sensitivity and better specificity. Still, for complete replacement of the conventional procedures in a non-endemic setting, the time-to-results of the real-time PCR is currently too long.
Collapse
Affiliation(s)
- R H T Nijhuis
- Department of Medical Microbiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
- Laboratory for Medical Microbiology and Immunology, Meander Medical Center, Amersfoort, The Netherlands
| | - L van Lieshout
- Department of Medical Microbiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - J J Verweij
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Laboratory for Medical Microbiology and Immunology, Elisabeth Hospital, Tilburg, The Netherlands
| | - E C J Claas
- Department of Medical Microbiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - E Wessels
- Department of Medical Microbiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
| |
Collapse
|
116
|
Saralamba N, Mayxay M, Newton PN, Smithuis F, Nosten F, Archasuksan L, Pukrittayakamee S, White NJ, Day NPJ, Dondorp AM, Imwong M. Genetic polymorphisms in the circumsporozoite protein of Plasmodium malariae show a geographical bias. Malar J 2018; 17:269. [PMID: 30012172 PMCID: PMC6048912 DOI: 10.1186/s12936-018-2413-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 07/09/2018] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Plasmodium malariae is characterized by its long asymptomatic persistence in the human host. The epidemiology of P. malariae is incompletely understood and is hampered by the limited knowledge of genetic polymorphisms. Previous reports from Africa have shown heterogeneity within the P. malariae circumsporozoite protein (pmcsp) gene. However, comparative studies from Asian countries are lacking. Here, the genetic polymorphisms in pmcsp of Asian isolates have been characterized. METHODS Blood samples from 89 symptomatic P. malariae-infected patients were collected, from Thailand (n = 43), Myanmar (n = 40), Lao PDR (n = 5), and Bangladesh (n = 1). pmcsp was amplified using semi-nested PCR before sequencing. The resulting 89 pmcsp sequences were analysed together with 58 previously published pmcsp sequences representing African countries using BioEdit, MEGA6, and DnaSP. RESULTS Polymorphisms identified in pmcsp were grouped into 3 populations: Thailand, Myanmar, and Kenya. The nucleotide diversity and the ratio of nonsynonymous to synonymous substitutions (dN/dS) in Thailand and Myanmar were higher compared with that in Kenya. Phylogenetic analysis showed clustering of pmcsp sequences according to the origin of isolates (Asia vs. Africa). High genetic differentiation (Fst = 0.404) was observed between P. malariae isolates from Asian and African countries. Sequence analysis of pmcsp showed the presence of tetrapeptide repeat units of NAAG, NDAG, and NAPG in the central repeat region of the gene. Plasmodium malariae isolates from Asian countries carried fewer copies of NAAG compared with that from African countries. The NAPG repeat was only observed in Asian isolates. Additional analysis of 2 T-cell epitopes, Th2R and Th3R, showed limited heterogeneity in P. malariae populations. CONCLUSIONS This study provides valuable information on the genetic polymorphisms in pmcsp isolates from Asia and advances our understanding of P. malariae population in Asia and Africa. Polymorphisms in the central repeat region of pmcsp showed association with the geographical origin of P. malariae isolates and can be potentially used as a marker for genetic epidemiology of P. malariae population.
Collapse
Affiliation(s)
- Naowarat Saralamba
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
- Faculty of Postgraduate Studies, University of Health Sciences, Vientiane, Lao PDR
- Centre for Tropical Medicine and Global Health, Churchill Hospital, University of Oxford, Oxford, UK
| | - Paul N Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
- Centre for Tropical Medicine and Global Health, Churchill Hospital, University of Oxford, Oxford, UK
| | - Frank Smithuis
- Medical Action Myanmar, Yangon, Myanmar
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7LF, UK
| | - Francois Nosten
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7LF, UK
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
| | - Laypaw Archasuksan
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
| | - Sasithon Pukrittayakamee
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Churchill Hospital, University of Oxford, Oxford, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Churchill Hospital, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Churchill Hospital, University of Oxford, Oxford, UK
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| |
Collapse
|
117
|
Dinko B, Amakpa E, Kweku M, Amoah P, Tampuori J, Adjuik M, Awandare GA, Deitsch KW. Plasmodium falciparum malaria cases detected for prompt treatment by rapid diagnostic tests in the Ho Teaching Hospital of the Volta Region of Ghana. Parasite Epidemiol Control 2018; 3:e00072. [PMID: 29988323 PMCID: PMC6020104 DOI: 10.1016/j.parepi.2018.e00072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 06/14/2018] [Accepted: 06/15/2018] [Indexed: 01/10/2023] Open
Abstract
Background Prompt diagnosis and effective treatment of malaria cases with efficacious drugs is an important strategy in the management and control of malaria in endemic populations. As part of a study investigating the factors modulating the development of Plasmodium falciparum gametocytes in the human host, we assessed the rate of RDT positivity of patients in different departments of the Ho Teaching Hospital and the relation with age and anaemia. Materials and methods Eight-hundred and ten individuals attending clinic at various departments within the Ho Teaching Hospital were screened for malaria antigenaemia using RDT as a point-of-entry investigation. RDT positive individuals were immediately treated for malaria whereas RDT negative individuals were treated for other ailments. Haematological analyses were performed for 69 of these patients and the relationship between RDT results and haemoglobin levels were investigated. Results The overall RDT positivity rate was 19.8% (160/810) of all individuals screened. There was no significant difference in the haemoglobin levels of RDT-positive and RDT-negative individuals (p value = 0.272). The highest number of attendees screened was children in the paediatric outpatient department and paediatric ward, 62% (507/810), with RDT positivity rate of 17% (91/507). We found the highest RDT positivity rate of 51% (19/37) in the male medical ward. Conclusions This study shows that RDT is a useful tool in promoting prompt diagnosis and management of malaria and though children form a majority of hospital attendees and malaria infections, the frequency of malaria detection may be higher in adults as compared to children.
Collapse
Affiliation(s)
- Bismarck Dinko
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Eric Amakpa
- Department of Obstetrics and Gyaenocology, Ho Teaching Hospital, Ho, Volta Regiona, Ghana
| | - Margaret Kweku
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Paul Amoah
- Diagnostic Laboratory, Ho Teaching Hospital, Ho, Volta Regiona, Ghana
| | - John Tampuori
- Department of Urology, Ho Teaching Hospital, Ho, Volta Regiona, Ghana
| | - Martin Adjuik
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Gordon A Awandare
- Department of Biochemistry, Cell and Molecular Biology and West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon-Accra, Ghana
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, USA
| |
Collapse
|
118
|
Zhou R, Liu Y, Li S, Zhao Y, Huang F, Yang C, Qian D, Lu D, Deng Y, Zhang H, Xu B. Polymorphisms analysis of the Plasmodium ovale tryptophan-rich antigen gene (potra) from imported malaria cases in Henan Province. Malar J 2018; 17:127. [PMID: 29566685 PMCID: PMC5865371 DOI: 10.1186/s12936-018-2261-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 03/08/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium ovale has two different subspecies: P. ovale curtisi and P. ovale wallikeri, which may be distinguished by the gene potra encoding P. ovale tryptophan-rich antigen. The sequence and size of potra gene was variable between the two P. ovale spp., and more fragment sizes were found compared to previous studies. Further information about the diversity of potra genes in these two P. ovale spp. will be needed. METHODS A total of 110 dried blood samples were collected from the clinical patients infected with P. ovale, who all returned from Africa in Henan Province in 2011-2016. The fragments of potra were amplified by nested PCR. The sizes and species of potra gene were analysed after sequencing, and the difference between the isolates were analysed with the alignment of the amino acid sequences. The phylogenetic tree was constructed by neighbour-joining to determine the genetic relationship among all the isolates. The distribution of the isolates was analysed based on the origin country. RESULTS Totally 67 samples infected with P. o. wallikeri, which included 8 genotypes of potra, while 43 samples infected with P. o. curtisi including 3 genotypes of potra. Combination with the previous studies, P. o. wallikeri had six sizes, 227, 245, 263, 281, 299 and 335 bp, and P. o. curtisi had four sizes, 299, 317, 335 and 353 bp, the fragment sizes of 299 and 335 bp were the overlaps between the two species. Six amino acid as one unit was firstly used to analyse the amino acid sequence of potra. Amino acid sequence alignment revealed that potra of P. o. wallikeri differed in two amino acid units, MANPIN and AITPIN, while potra of P. o. curtisi differed in amino acid units TINPIN and TITPIS. Combination with the previous studies, there were ten subtypes of potra exiting for P. o. wallikeri and four subtypes for P. o. curtisi. The phylogenetic tree showed that 11 isolates were divided into two clusters, P. o. wallikeri which was then divided into five sub-clusters, and P. o. curtisi which also formed two sub-clusters with their respective reference sequences. The genetic relationship of the P. ovale spp. mainly based on the number of the dominant amino acid repeats, the number of MANPIN, AITPIN, TINPIN or TITPIS. The genotype of the 245 bp size for P. o. wallikeri and that of the 299 and 317 bp size for P. o. curtisi were commonly exiting in Africa. CONCLUSION This study further proved that more fragment sizes were found, P. o. wallikeri had six sizes, P. o. curtisi had four sizes. There were ten subtypes of potra exiting for P. o. wallikeri and four subtypes for P. o. curtisi. The genetic polymorphisms of potra provided complementary information for the gene tracing of P. ovale spp. in the malaria elimination era.
Collapse
Affiliation(s)
- Ruimin Zhou
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China
| | - Ying Liu
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China
| | - Suhua Li
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China
| | - Yuling Zhao
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China
| | - Fang Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China
| | - Chengyun Yang
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China
| | - Dan Qian
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China
| | - Deling Lu
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China
| | - Yan Deng
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China
| | - Hongwei Zhang
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China.
| | - Bianli Xu
- Department of Parasite Disease Control and Prevention, Henan Province Center for Disease Control and Prevention, Zhengzhou, 450016, People's Republic of China.
| |
Collapse
|
119
|
de Alencar FEC, Malafronte RDS, Cerutti Junior C, Natal Fernandes L, Buery JC, Fux B, Rezende HR, Duarte AMRDC, Medeiros-Sousa AR, Miranda AE. Assessment of asymptomatic Plasmodium spp. infection by detection of parasite DNA in residents of an extra-Amazonian region of Brazil. Malar J 2018. [PMID: 29540186 PMCID: PMC5853114 DOI: 10.1186/s12936-018-2263-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background The hypotheses put forward to explain the malaria transmission cycle in extra-Amazonian Brazil, an area of very low malaria incidence, are based on either a zoonotic scenario involving simian malaria, or a scenario in which asymptomatic carriers play an important role. Objectives To determine the incidence of asymptomatic infection by detecting Plasmodium spp. DNA and its role in residual malaria transmission in a non-Amazonian region of Brazil. Methods Upon the report of the first malaria case in 2010 in the Atlantic Forest region of the state of Espírito Santo, inhabitants within a 2 km radius were invited to participate in a follow-up study. After providing signed informed consent forms, inhabitants filled out a questionnaire and gave blood samples for PCR, and thick and thin smears. Follow-up visits were performed every 3 months over a 21 month period, when new samples were collected and information was updated. Results Ninety-two individuals were initially included for follow-up. At the first collection, all of them were clearly asymptomatic. One individual was positive for Plasmodium vivax, one for Plasmodium malariae and one for both P. vivax and P. malariae, corresponding to a prevalence of 3.4% (2.3% for each species). During follow-up, four new PCR-positive cases (two for each species) were recorded, corresponding to an incidence of 2.5 infections per 100 person-years or 1.25 infections per 100 person-years for each species. A mathematical transmission model was applied, using a low frequency of human carriers and the vector density in the region, and calculated based on previous studies in the same locality whose results were subjected to a linear regression. This analysis suggests that the transmission chain is unlikely to be based solely on human carriers, regardless of whether they are symptomatic or not. Conclusion The low incidence of cases and the low frequency of asymptomatic malaria carriers investigated make it unlikely that the transmission chain in the region is based solely on human hosts, as cases are isolated one from another by hundreds of kilometers and frequently by long periods of time, reinforcing instead the hypothesis of zoonotic transmission. Electronic supplementary material The online version of this article (10.1186/s12936-018-2263-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Filomena E C de Alencar
- Graduate Programme in Infectious Diseases, Federal University of Espírito Santo, Vitória, Brazil.
| | | | - Crispim Cerutti Junior
- Graduate Programme in Infectious Diseases, Federal University of Espírito Santo, Vitória, Brazil
| | - Lícia Natal Fernandes
- Protozoology Laboratory, Institute of Tropical Medicine, University of São Paulo, São Paulo, Brazil
| | - Julyana Cerqueira Buery
- Graduate Programme in Infectious Diseases, Federal University of Espírito Santo, Vitória, Brazil
| | - Blima Fux
- Graduate Programme in Infectious Diseases, Federal University of Espírito Santo, Vitória, Brazil
| | - Helder Ricas Rezende
- Entomology and Malacology Unit, Espírito Santo State Department of Health (SESA), Vitória, Brazil
| | | | | | | |
Collapse
|
120
|
Panda SK, Luyten W. Antiparasitic activity in Asteraceae with special attention to ethnobotanical use by the tribes of Odisha, India. Parasite 2018; 25:10. [PMID: 29528842 PMCID: PMC5847338 DOI: 10.1051/parasite/2018008] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 02/03/2018] [Indexed: 12/11/2022] Open
Abstract
The purpose of this review is to survey the antiparasitic plants of the Asteraceae family and their applicability in the treatment of parasites. This review is divided into three major parts: (a) literature on traditional uses of Asteraceae plants for the treatment of parasites; (b) description of the major classes of chemical compounds from Asteraceae and their antiparasitic effects; and (c) antiparasitic activity with special reference to flavonoids and terpenoids. This review provides detailed information on the reported Asteraceae plant extracts found throughout the world and on isolated secondary metabolites that can inhibit protozoan parasites such as Plasmodium, Trypanosoma, Leishmania, and intestinal worms. Additionally, special attention is given to the Asteraceae plants of Odisha, used by the tribes of the area as antiparasitics. These plants are compared to the same plants used traditionally in other regions. Finally, we provide information on which plants identified in Odisha, India and related compounds show promise for the development of new drugs against parasitic diseases. For most of the plants discussed in this review, the active compounds still need to be isolated and tested further.
Collapse
Affiliation(s)
- Sujogya Kumar Panda
- Department of Zoology, North Orissa University,
Baripada-
757003 India
- Department of Biology, KU Leuven,
3000
Leuven Belgium
| | - Walter Luyten
- Department of Biology, KU Leuven,
3000
Leuven Belgium
| |
Collapse
|
121
|
Prospective Clinical Trial Assessing Species-Specific Efficacy of Artemether-Lumefantrine for the Treatment of Plasmodium malariae, Plasmodium ovale, and Mixed Plasmodium Malaria in Gabon. Antimicrob Agents Chemother 2018; 62:AAC.01758-17. [PMID: 29311086 DOI: 10.1128/aac.01758-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 12/20/2017] [Indexed: 11/20/2022] Open
Abstract
Treatment recommendations for Plasmodium malariae and Plasmodium ovale malaria are largely based on anecdotal evidence. The aim of this prospective study, conducted in Gabon, was to systematically assess the efficacy and safety of artemether-lumefantrine for the treatment of patients with uncomplicated P. malariae or P. ovale species monoinfections or mixed Plasmodium infections. Patients with microscopically confirmed P. malariae, P. ovale, or mixed-species malaria with at least one of these two Plasmodium species were treated with an oral, fixed-dose combination of artemether-lumefantrine for 3 consecutive days. The primary endpoints were per-protocol PCR-corrected adequate clinical and parasitological response (ACPR) on days 28 and 42. Tolerability and safety were recorded throughout the follow-up period. Seventy-two participants (42 male and 30 female) were enrolled; 62.5% of them had PCR-corrected mixed Plasmodium infections. Per protocol, PCR-corrected ACPR rates were 96.6% (95% confidence interval [CI], 91.9 to 100) on day 28 and 94.2% (95% CI, 87.7 to 100) on day 42. Considering Plasmodium species independently from their coinfecting species, day 42 ACPR rates were 95.5% (95% CI, 89.0 to 100) for P. falciparum, 100% (exact CI, 84.6 to 100) for P. malariae, 100% (exact CI, 76.8 to 100) for P. ovale curtisi, and 90.9% (95% CI, 70.7 to 100) for P. ovale wallikeri Study drug-related adverse events were generally mild or moderate. In conclusion, this clinical trial demonstrated satisfying antimalarial activity of artemether-lumefantrine against P. ovalewallikeri, P. ovale curtisi, P. malariae, and mixed Plasmodium infections, with per-protocol efficacies of 90% to 100% and without evident tolerability or safety concerns. (This trial was registered in the clinical study database ClinicalTrials.gov under the identifier NCT02528279.).
Collapse
|
122
|
Veletzky L, Groger M, Lagler H, Walochnik J, Auer H, Fuehrer HP, Ramharter M. Molecular evidence for relapse of an imported Plasmodium ovale wallikeri infection. Malar J 2018; 17:78. [PMID: 29426330 PMCID: PMC5807828 DOI: 10.1186/s12936-018-2226-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/07/2018] [Indexed: 11/12/2022] Open
Abstract
Background Malaria caused by Plasmodium ovale spp. has been neglected by and large from research and has received only little scientific attention during the past decades. Ovale malaria is considered to feature relapses by liver hypnozoites although scientific evidence for this paradigm is scarce. Case presentation Here, the case of a 16-year-old male, who presented with fevers to the outpatient department in Vienna, Austria, after travelling to Uganda and Papua New Guinea is described. Infection with Plasmodium malariae was diagnosed by microscopy and the patient was treated accordingly with a full course of supervised artemether–lumefantrine. He was discharged in good clinical condition with a negative blood smear. One month after initial diagnosis, he returned complaining of fever. Thick blood smear was positive again for malaria parasites, which were confirmed as P. ovale wallikeri by PCR. Retrospective analysis revealed the identical Plasmodium spp. in the initial blood samples. Molecular analysis of various gene loci (nuclear porbp2, 18S rRNA and potra genes) gave identical results providing further evidence for relapse by an identical parasite genotype. Consecutively, the patient was retreated with artemether–lumefantrine and received a regimen of primaquine according to WHO guidelines. Conclusion Conclusive evidence for relapses with P. ovale spp. is rare. The presented case provides convincing confirmation for the relapse paradigm based on re-appearing parasitaemia following supervised treatment in a non-endemic region with a parasite strain of identical genotype.
Collapse
Affiliation(s)
- Luzia Veletzky
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria.,Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany
| | - Mirjam Groger
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Heimo Lagler
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Julia Walochnik
- Institute for Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Herbert Auer
- Institute for Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Hans-Peter Fuehrer
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Michael Ramharter
- Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany. .,Bernhard Nocht Hospital for Tropical Diseases, Bernhard Nocht Institute for Tropical Medicine and University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| |
Collapse
|
123
|
Komaki-Yasuda K, Vincent JP, Nakatsu M, Kato Y, Ohmagari N, Kano S. A novel PCR-based system for the detection of four species of human malaria parasites and Plasmodium knowlesi. PLoS One 2018; 13:e0191886. [PMID: 29370297 PMCID: PMC5785027 DOI: 10.1371/journal.pone.0191886] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/12/2018] [Indexed: 11/22/2022] Open
Abstract
A microscopy-based diagnosis is the gold standard for the detection and identification of malaria parasites in a patient’s blood. However, the detection of cases involving a low number of parasites and the differentiation of species sometimes requires a skilled microscopist. Although PCR-based diagnostic methods are already known to be very powerful tools, the time required to apply such methods is still much longer in comparison to traditional microscopic observation. Thus, improvements to PCR systems are sought to facilitate the more rapid and accurate detection of human malaria parasites Plasmodium falciparum, P. vivax, P. ovale, and P. malariae, as well as P. knowlesi, which is a simian malaria parasite that is currently widely distributed in Southeast Asia. A nested PCR that targets the small subunit ribosomal RNA genes of malaria parasites was performed using a “fast PCR enzyme”. In the first PCR, universal primers for all parasite species were used. In the second PCR, inner-specific primers, which targeted sequences from P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi, were used. The PCR reaction time was reduced with the use of the “fast PCR enzyme”, with only 65 minutes required to perform the first and second PCRs. The specific primers only reacted with the sequences of their targeted parasite species and never cross-reacted with sequences from other species under the defined PCR conditions. The diagnoses of 36 clinical samples that were obtained using this new PCR system were highly consistent with the microscopic diagnoses.
Collapse
Affiliation(s)
- Kanako Komaki-Yasuda
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan
| | - Jeanne Perpétue Vincent
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan
| | - Masami Nakatsu
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan
| | - Yasuyuki Kato
- Disease Control and Prevention Center of National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan
| | - Norio Ohmagari
- Disease Control and Prevention Center of National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan
| | - Shigeyuki Kano
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan
- * E-mail:
| |
Collapse
|
124
|
Joste V, Kamaliddin C, Kendjo E, Hubert V, Argy N, Houzé S. Distinction of Plasmodium ovale wallikeri and Plasmodium ovale curtisi using quantitative Polymerase Chain Reaction with High Resolution Melting revelation. Sci Rep 2018; 8:300. [PMID: 29321578 PMCID: PMC5762660 DOI: 10.1038/s41598-017-18026-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/28/2017] [Indexed: 11/22/2022] Open
Abstract
Plasmodium ovale curtisi (Poc) and Plasmodium ovale wallikeri (Pow) have been described as two distinct species, only distinguishable by molecular methods such as PCR. Because of no well-defined endemic area and a variable clinical presentation as higher thrombocytopenia and nausea associated with Pow infection and asymptomatic forms of the pathology with Poc infection, rapid and specific identification of Plasmodium ovale curtisi and Plasmodium ovale wallikeri are needed. The aim of the study was to evaluate a new quantitative real-time PCR coupled with high resolution melting revelation (qPCR-HRM) for identification of both species. Results were compared with a nested-PCR, considered as a gold standard for Pow and Poc distinction. 356 samples including all human Plasmodium species at various parasitaemia were tested. The qPCR-HRM assay allowed Poc and Pow discrimination in 66 samples tested with a limit of detection evaluated at 1 parasite/µL. All these results were concordant with nested-PCR. Cross-reaction was absent with others blood parasites. The qPCR-HRM is a rapid and convenient technique to Poc and Pow distinction.
Collapse
Affiliation(s)
- V Joste
- National French Malaria Reference Center, Bichat-Claude Bernard Hospital, 75018, Paris, France.
- Parasitology and Mycology Laboratory, Bichat-Claude Bernard Hospital, APHP, 75018, Paris, France.
| | - C Kamaliddin
- National French Malaria Reference Center, Bichat-Claude Bernard Hospital, 75018, Paris, France
- UMR216- MERIT, COMUE Sorbonne Paris Cité, Faculté de Pharmacie de Paris, Paris Descartes University, Paris, 75006, France
| | - E Kendjo
- National French Malaria Reference Center, Bichat-Claude Bernard Hospital, 75018, Paris, France
- National French Malaria Reference Center, Pitié Salpetrière hospital, 75013, Paris, France
| | - V Hubert
- National French Malaria Reference Center, Bichat-Claude Bernard Hospital, 75018, Paris, France
- UMR216- MERIT, COMUE Sorbonne Paris Cité, Faculté de Pharmacie de Paris, Paris Descartes University, Paris, 75006, France
| | - N Argy
- National French Malaria Reference Center, Bichat-Claude Bernard Hospital, 75018, Paris, France
- Parasitology and Mycology Laboratory, Bichat-Claude Bernard Hospital, APHP, 75018, Paris, France
- UMR216- MERIT, COMUE Sorbonne Paris Cité, Faculté de Pharmacie de Paris, Paris Descartes University, Paris, 75006, France
| | - S Houzé
- National French Malaria Reference Center, Bichat-Claude Bernard Hospital, 75018, Paris, France
- Parasitology and Mycology Laboratory, Bichat-Claude Bernard Hospital, APHP, 75018, Paris, France
- UMR216- MERIT, COMUE Sorbonne Paris Cité, Faculté de Pharmacie de Paris, Paris Descartes University, Paris, 75006, France
| |
Collapse
|
125
|
Spry C, Sewell AL, Hering Y, Villa MV, Weber J, Hobson SJ, Harnor SJ, Gul S, Marquez R, Saliba KJ. Structure-activity analysis of CJ-15,801 analogues that interact with Plasmodium falciparum pantothenate kinase and inhibit parasite proliferation. Eur J Med Chem 2018; 143:1139-1147. [DOI: 10.1016/j.ejmech.2017.08.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/22/2017] [Accepted: 08/22/2017] [Indexed: 12/25/2022]
|
126
|
[Plasmodium ovale wallikeri and Plasmodium ovale curtisi Malaria in Senegal in 2016]. ACTA ACUST UNITED AC 2017; 110:286-290. [PMID: 29127650 DOI: 10.1007/s13149-017-0578-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/26/2017] [Indexed: 10/18/2022]
Abstract
Recently in Senegal, a case of Plasmodium ovale malaria had led to a diagnostic difficulty due to the ignorance of this parasite and the neglect of it. The objective of this study was to actively investigate cases of P. ovale malaria that would be misdiagnosed in the health centre structures of Senegal. The study was conducted in three areas that reflect different epidemiological strata of malaria. Microscopy was performed by microscopy experts on suspected malaria patients. The results were validated by Rougemont real-time PCR. Positive P. ovale cases were genotyped by nested PCR targeting the potra gene. A total of 406 samples were taken. Microscopy of Giemsa stained thick and thin smears recorded 228 cases of Plasmodium falciparum (97%), 3 cases of Plasmodium malariae (1.3%), and 4 cases of P. ovale (1.7%). The cases of P. ovale observed at microscopy were confirmed by real-time PCR. Genotyping of P. ovale revealed 3 cases of P. ovale wallikeri and 1 case of P. ovale curtisi. The prevalence of P. ovale malaria remains low in Senegal. However, malaria microscopists should be trained to recognize non-falciparum species in order to avoid the diagnostic delays and unnecessary investigations. National malaria control program should consider those species for the better management of malaria control in the country. Simplified molecular methods like, loop-mediated isothermal amplification (LAMP) may be useful to better characterize the epidemiology of non-falciparum malaria.
Collapse
|
127
|
Lim C, Dankwa S, Paul AS, Duraisingh MT. Host Cell Tropism and Adaptation of Blood-Stage Malaria Parasites: Challenges for Malaria Elimination. Cold Spring Harb Perspect Med 2017; 7:a025494. [PMID: 28213436 PMCID: PMC5666624 DOI: 10.1101/cshperspect.a025494] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Plasmodium falciparum and Plasmodium vivax account for most of the mortality and morbidity associated with malaria in humans. Research and control efforts have focused on infections caused by P. falciparum and P. vivax, but have neglected other malaria parasite species that infect humans. Additionally, many related malaria parasite species infect nonhuman primates (NHPs), and have the potential for transmission to humans. For malaria elimination, the varied and specific challenges of all of these Plasmodium species will need to be considered. Recent advances in molecular genetics and genomics have increased our knowledge of the prevalence and existing diversity of the human and NHP Plasmodium species. We are beginning to identify the extent of the reservoirs of each parasite species in humans and NHPs, revealing their origins as well as potential for adaptation in humans. Here, we focus on the red blood cell stage of human infection and the host cell tropism of each human Plasmodium species. Determinants of tropism are unique among malaria parasite species, presenting a complex challenge for malaria elimination.
Collapse
Affiliation(s)
- Caeul Lim
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Selasi Dankwa
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Aditya S Paul
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115
| | | |
Collapse
|
128
|
Malaria Epidemiology at the Clone Level. Trends Parasitol 2017; 33:974-985. [PMID: 28966050 DOI: 10.1016/j.pt.2017.08.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/14/2017] [Accepted: 08/30/2017] [Indexed: 01/08/2023]
Abstract
Genotyping to distinguish between parasite clones is nowadays a standard in many molecular epidemiological studies of malaria. It has become crucial in drug trials and to follow individual clones in epidemiological studies, and to understand how drug resistance emerges and spreads. Here, we review the applications of the increasingly available genotyping tools and whole-genome sequencing data, and argue for a better integration of population genetics findings into malaria-control strategies.
Collapse
|
129
|
Abstract
The Plasmodium genus has evolved over time and across hosts, complexifying our understanding of malaria. In a recent Nature paper, Rutledge et al. (2017) describe the genome sequences of three major human malaria parasite species, providing insight into Plasmodium evolution and raising the question of how many species there are.
Collapse
Affiliation(s)
- Jane M Carlton
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003, USA.
| | - Steven A Sullivan
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003, USA
| |
Collapse
|
130
|
Imai K, Tarumoto N, Misawa K, Runtuwene LR, Sakai J, Hayashida K, Eshita Y, Maeda R, Tuda J, Murakami T, Maesaki S, Suzuki Y, Yamagishi J, Maeda T. A novel diagnostic method for malaria using loop-mediated isothermal amplification (LAMP) and MinION™ nanopore sequencer. BMC Infect Dis 2017; 17:621. [PMID: 28903726 PMCID: PMC5598014 DOI: 10.1186/s12879-017-2718-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 09/06/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND A simple and accurate molecular diagnostic method for malaria is urgently needed due to the limitations of conventional microscopic examination. In this study, we demonstrate a new diagnostic procedure for human malaria using loop mediated isothermal amplification (LAMP) and the MinION™ nanopore sequencer. METHODS We generated specific LAMP primers targeting the 18S-rRNA gene of all five human Plasmodium species including two P. ovale subspecies (P. falciparum, P. vivax, P. ovale wallikeri, P. ovale curtisi, P. knowlesi and P. malariae) and examined human blood samples collected from 63 malaria patients in Indonesia. Additionally, we performed amplicon sequencing of our LAMP products using MinION™ nanopore sequencer to identify each Plasmodium species. RESULTS Our LAMP method allowed amplification of all targeted 18S-rRNA genes of the reference plasmids with detection limits of 10-100 copies per reaction. Among the 63 clinical samples, 54 and 55 samples were positive by nested PCR and our LAMP method, respectively. Identification of the Plasmodium species by LAMP amplicon sequencing analysis using the MinION™ was consistent with the reference plasmid sequences and the results of nested PCR. CONCLUSIONS Our diagnostic method combined with LAMP and MinION™ could become a simple and accurate tool for the identification of human Plasmodium species, even in resource-limited situations.
Collapse
Affiliation(s)
- Kazuo Imai
- Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Norihito Tarumoto
- Department of Infectious Disease and Infection Control, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan.,Center for Clinical Infectious Diseases and Research, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan
| | - Kazuhisa Misawa
- Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Lucky Ronald Runtuwene
- Department of Computational Biology and Medical Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan
| | - Jun Sakai
- Department of Infectious Disease and Infection Control, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan.,Center for Clinical Infectious Diseases and Research, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan
| | - Kyoko Hayashida
- Research Center for Zoonosis Control, Hokkaido University, North 20, West 10 Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Yuki Eshita
- Research Center for Zoonosis Control, Hokkaido University, North 20, West 10 Kita-ku, Sapporo, Hokkaido, 001-0020, Japan.,Faculty of Medicine, Oita University, 1-1 Hasama-machi, Yufu, Oita, 879-5593, Japan.,Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Thung Phaya, Ratchathewi, Bangkok, 10400, Thailand.,Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Ryuichiro Maeda
- Division of Biomedical Sciences, Department of Basic Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido, 080-8555, Japan
| | - Josef Tuda
- Department of Parasitology, Faculty of Medicine, Sam Ratulangi University, Kampus Unsrat, Manado, Bahu, 95115, Indonesia
| | - Takashi Murakami
- Center for Clinical Infectious Diseases and Research, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan.,Department of Microbiology, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan
| | - Shigefumi Maesaki
- Department of Infectious Disease and Infection Control, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan.,Center for Clinical Infectious Diseases and Research, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan
| | - Yutaka Suzuki
- Department of Computational Biology and Medical Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan
| | - Junya Yamagishi
- Research Center for Zoonosis Control, Hokkaido University, North 20, West 10 Kita-ku, Sapporo, Hokkaido, 001-0020, Japan.,Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, North 20, West 10 Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Takuya Maeda
- Center for Clinical Infectious Diseases and Research, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan. .,Department of Microbiology, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan.
| |
Collapse
|
131
|
Pollak JJ, Houri-Yafin A, Salpeter SJ. Computer Vision Malaria Diagnostic Systems-Progress and Prospects. Front Public Health 2017; 5:219. [PMID: 28879175 PMCID: PMC5573428 DOI: 10.3389/fpubh.2017.00219] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/07/2017] [Indexed: 12/17/2022] Open
Abstract
Accurate malaria diagnosis is critical to prevent malaria fatalities, curb overuse of antimalarial drugs, and promote appropriate management of other causes of fever. While several diagnostic tests exist, the need for a rapid and highly accurate malaria assay remains. Microscopy and rapid diagnostic tests are the main diagnostic modalities available, yet they can demonstrate poor performance and accuracy. Automated microscopy platforms have the potential to significantly improve and standardize malaria diagnosis. Based on image recognition and machine learning algorithms, these systems maintain the benefits of light microscopy and provide improvements such as quicker scanning time, greater scanning area, and increased consistency brought by automation. While these applications have been in development for over a decade, recently several commercial platforms have emerged. In this review, we discuss the most advanced computer vision malaria diagnostic technologies and investigate several of their features which are central to field use. Additionally, we discuss the technological and policy barriers to implementing these technologies in low-resource settings world-wide.
Collapse
|
132
|
Bichara C, Flahaut P, Costa D, Bienvenu AL, Picot S, Gargala G. Cryptic Plasmodium ovale concurrent with mixed Plasmodium falciparum and Plasmodium malariae infection in two children from Central African Republic. Malar J 2017; 16:339. [PMID: 28810865 PMCID: PMC5558716 DOI: 10.1186/s12936-017-1979-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 08/07/2017] [Indexed: 12/02/2022] Open
Abstract
Background Since several malaria parasite species are usually present in a particular area, co-infections with more than one species of Plasmodium are more likely to occur in humans infected in these areas. In many mixed infections, parasite densities of the cryptic species may be low and often not recognized in clinical practice. Case presentation Two children (3 and 6 years old) adopted recently from Central African Republic were admitted to hospital because of intermittent fever. Thin blood smears stained with Giemsa showed Plasmodium falciparum and Plasmodium malariae co-infection for both children at admission. They were both treated with atovaquone-proguanil combination for 3 days. At day 7, both thin blood smears examination remained negative but at day 28, thin blood smear was positive for P. malariae trophozoites and for Plasmodium ovale for the girl and her brother, respectively. Samples collected at day 1 and day 28 were submitted to real-time PCR showing the presence of the three parasite species (P. falciparum, P malariae and P. ovale) in admission blood samples from the two children and only P. ovale at day 28. Conclusions Twenty-eight days follow-up after treatment led to detection of a third parasite species in the blood of these two patients suggesting covert co-infection and a delayed appearance of one cryptic species following treatment. Concurrently infecting malaria species could be mutually suppressive, with P. falciparum tending to dominate other species. These observations provide more evidence that recommendations for treatment of imported malaria should take into account the risk of concurrent or cryptic infection with Plasmodium species. Clinicians and biologists should be aware of the underestimated frequency of mixed infections with cryptic species and of the importance of patient follow-up at day 28. Future guidelines should shed more light on the treatment of mixed infection and on the interest of using artemisinin-based combinations for falciparum and non-falciparum species.
Collapse
Affiliation(s)
- Cynthia Bichara
- Department of Parasitology-Mycology, Rouen University Hospital, 76 000, Rouen, France
| | - Philippe Flahaut
- Department of Pediatrics, Rouen University Hospital, 76 000, Rouen, France
| | - Damien Costa
- Department of Parasitology-Mycology, Rouen University Hospital, 76 000, Rouen, France
| | - Anne-Lise Bienvenu
- Malaria Research Unit, SMITh, ICBMS UMR 5246 CNRS, University Lyon 1, Lyon, France
| | - Stephane Picot
- Malaria Research Unit, SMITh, ICBMS UMR 5246 CNRS, University Lyon 1, Lyon, France.,Institut de Parasitologie-Mycologie Médicale, Hospices Civils de Lyon, Lyon, France
| | - Gilles Gargala
- Department of Parasitology-Mycology, Rouen University Hospital, 76 000, Rouen, France.
| |
Collapse
|
133
|
Lim KL, Amir A, Lau YL, Fong MY. The Duffy binding protein (PkDBPαII) of Plasmodium knowlesi from Peninsular Malaysia and Malaysian Borneo show different binding activity level to human erythrocytes. Malar J 2017; 16:331. [PMID: 28800732 PMCID: PMC5553923 DOI: 10.1186/s12936-017-1984-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 08/07/2017] [Indexed: 12/01/2022] Open
Abstract
Background The zoonotic Plasmodium knowlesi is a major cause of human malaria in Malaysia. This parasite uses the Duffy binding protein (PkDBPαII) to interact with the Duffy antigen receptor for chemokines (DARC) receptor on human and macaque erythrocytes to initiate invasion. Previous studies on P. knowlesi have reported distinct Peninsular Malaysia and Malaysian Borneo PkDBPαII haplotypes. In the present study, the differential binding activity of these haplotypes with human and macaque (Macaca fascicularis) erythrocytes was investigated. Methods The PkDBPαII of Peninsular Malaysia and Malaysian Borneo were expressed on the surface of COS-7 cells and tested with human and monkey erythrocytes, with and without anti-Fy6 (anti-Duffy) monoclonal antibody treatment. Binding activity level was determined by counting the number of rosettes formed between the transfected COS-7 cells and the erythrocytes. Results Anti-Fy6 treatment was shown to completely block the binding of human erythrocytes with the transfected COS-7 cells, thus verifying the specific binding of human DARC with PkDBPαII. Interestingly, the PkDBPαII of Peninsular Malaysia displayed a higher binding activity with human erythrocytes when compared with the Malaysian Borneo PkDBPαII haplotype (mean number of rosettes formed = 156.89 ± 6.62 and 46.00 ± 3.57, respectively; P < 0.0001). However, no difference in binding activity level was seen in the binding assay using M. fascicularis erythrocytes. Conclusion This study is the first report of phenotypic difference between PkDBPαII haplotypes. The biological implication of this finding is yet to be determined. Therefore, further studies need to be carried out to determine whether this differential binding level can be associated with severity of knowlesi malaria in human.
Collapse
Affiliation(s)
- Khai Lone Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Amirah Amir
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| |
Collapse
|
134
|
Abstract
Malaria is caused in humans by five species of single-celled eukaryotic Plasmodium parasites (mainly Plasmodium falciparum and Plasmodium vivax) that are transmitted by the bite of Anopheles spp. mosquitoes. Malaria remains one of the most serious infectious diseases; it threatens nearly half of the world's population and led to hundreds of thousands of deaths in 2015, predominantly among children in Africa. Malaria is managed through a combination of vector control approaches (such as insecticide spraying and the use of insecticide-treated bed nets) and drugs for both treatment and prevention. The widespread use of artemisinin-based combination therapies has contributed to substantial declines in the number of malaria-related deaths; however, the emergence of drug resistance threatens to reverse this progress. Advances in our understanding of the underlying molecular basis of pathogenesis have fuelled the development of new diagnostics, drugs and insecticides. Several new combination therapies are in clinical development that have efficacy against drug-resistant parasites and the potential to be used in single-dose regimens to improve compliance. This ambitious programme to eliminate malaria also includes new approaches that could yield malaria vaccines or novel vector control strategies. However, despite these achievements, a well-coordinated global effort on multiple fronts is needed if malaria elimination is to be achieved.
Collapse
Affiliation(s)
- Margaret A Phillips
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA
| | | | | | | | - Wesley C Van Voorhis
- University of Washington, Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Re-emerging Infectious Diseases, Seattle, Washington, USA
| | | |
Collapse
|
135
|
Ntege EH, Takashima E, Morita M, Nagaoka H, Ishino T, Tsuboi T. Blood-stage malaria vaccines: post-genome strategies for the identification of novel vaccine candidates. Expert Rev Vaccines 2017; 16:769-779. [PMID: 28604122 DOI: 10.1080/14760584.2017.1341317] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION An efficacious malaria vaccine is necessary to advance the current control measures towards malaria elimination. To-date, only RTS,S/AS01, a leading pre-erythrocytic stage vaccine completed phase 3 trials, but with an efficacy of 28-36% in children, and 18-26% in infants, that waned over time. Blood-stage malaria vaccines protect against disease, and are considered effective targets for the logical design of next generation vaccines to improve the RTS,S field efficacy. Therefore, novel blood-stage vaccine candidate discovery efforts are critical, albeit with several challenges including, high polymorphisms in vaccine antigens, poor understanding of targets of naturally protective immunity, and difficulties in the expression of high AT-rich plasmodial proteins. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects of malaria vaccine research and development. We focused on post-genome vaccine candidate discovery, malaria vaccine development, sequence diversity, pre-clinical and clinical trials. Expert commentary: Post-genome high-throughput technologies using wheat germ cell-free protein synthesis technology and immuno-profiling with sera from malaria patients with clearly defined outcomes are highlighted to overcome current challenges of malaria vaccine candidate discovery.
Collapse
Affiliation(s)
- Edward H Ntege
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Eizo Takashima
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Masayuki Morita
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Hikaru Nagaoka
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Tomoko Ishino
- b Division of Molecular Parasitology , Proteo-Science Center, Ehime University , Toon , Ehime , Japan
| | - Takafumi Tsuboi
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| |
Collapse
|
136
|
Owusu EDA, Brown CA, Grobusch MP, Mens P. Prevalence of Plasmodium falciparum and non-P. falciparum infections in a highland district in Ghana, and the influence of HIV and sickle cell disease. Malar J 2017; 16:167. [PMID: 28438159 PMCID: PMC5404324 DOI: 10.1186/s12936-017-1823-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 04/18/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND In the past two decades, there has been a reported decline in malaria in Ghana and the rest of the world; yet it remains the number one cause of mortality and morbidity. Human immuno-deficiency virus (HIV) and sickle cell disease (SCD) share a common geographical space with malaria in sub-Saharan Africa and an interaction between these three conditions has been suggested. This study determined the Plasmodium falciparum and non-P. falciparum status of symptomatic and non-symptomatic residents of Mpraeso in the highlands of Kwahu-South district of Ghana based on evidence of current national decline. The influence of HIV and SCD on malaria was also determined. METHODS Participants were 354 symptomatic patients visiting the Kwahu Government Hospital and 360 asymptomatic residents of the district capital. This cross-sectional study was conducted during the minor rainy season (October-December 2014). Rapid diagnostic tests (RDT), blood film microscopy and real-time polymerase chain reaction assessment of blood were done. Participants who tested positive with RDT were treated with artemisinin-based combination therapy; and assessment of venous blood was repeated 7 days after treatment. HIV screening and haemoglobin genotyping was done. Univariate and multivariate regression analysis was used to determine the influence of SCD and HIV. RESULTS Plasmodium falciparum was prevalent at 124/142 (87.3%). Plasmodium malariae was the only non-falciparum species detected at 18/142 (12.7%). HIV and SCD did not significantly increase odds of malaria infection. However, the use of ITN and recent anti-malarial intake significantly decreased the odds of being malaria infected by 0.45-fold and 0.46-fold respectively. CONCLUSION Plasmodium falciparum and P. malariae infection are the prevailing species in the study area; albeit varying from the national average. HIV and SCD were not associated with the risk of having malaria.
Collapse
Affiliation(s)
- Ewurama D A Owusu
- Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Korle-bu, Accra, Ghana. .,Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
| | - Charles A Brown
- Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Korle-bu, Accra, Ghana
| | - Martin P Grobusch
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.,Centre de Recherches Médicales de Lambaréné (CERMEL), Hôpital Albert Schweitzer, Lambaréné, Gabon.,Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Petra Mens
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.,Department of Medical Microbiology, Clinical Parasitology, Division of Laboratory Specialisms, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
137
|
Gunawardena S, Daniels RF, Yahathugoda TC, Weerasooriya MV, Durfee K, Volkman SK, Wirth DF, Karunaweera ND. Case report of Plasmodium ovale curtisi malaria in Sri Lanka: relevance for the maintenance of elimination status. BMC Infect Dis 2017; 17:307. [PMID: 28438137 PMCID: PMC5404676 DOI: 10.1186/s12879-017-2411-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 04/20/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Following its recent certification as malaria-free, imported infections now pose the greatest threat for maintaining this status in Sri Lanka. Imported infections may also introduce species that are uncommon or not previously endemic to these areas. We highlight in this case report the increasing importance of less common malaria species such as Plasmodium ovale in elimination settings and discuss its relevance for the risk of malaria resurgence in the country. CASE PRESENTATION A 41-year-old patient from southern Sri Lanka was diagnosed with malaria after 8 days of fever. Microscopy of blood smears revealed parasites morphologically similar to P. vivax and the rapid diagnostic test was indicative of non-P. falciparum malaria. He was treated with chloroquine over 3 days and primaquine for 14 days. He was negative for malaria at a one-year follow-up. Molecular testing performed subsequently confirmed that infection was caused by P. ovale curtisi. The patient gave a history of P. vivax malaria treated with chloroquine and primaquine. He also provided a history of travel to malaria endemic regions, including residing in Liberia from May 2012 to November 2013, throughout which he was on weekly malaria prophylaxis with mefloquine. He had also visited India on an eight-day Buddhist pilgrimage tour in September 2014 without malaria prophylaxis. CONCLUSIONS It is crucial that every case of malaria is investigated thoroughly and necessary measures taken to prevent re-introduction of malaria. Accurate molecular diagnostic techniques need to be established in Sri Lanka for the screening and diagnosis of all species of human malaria infections, especially those that may occur with low parasitemia and are likely to be undetected using the standard techniques currently in use. In addition, ascertaining whether an infection occurred through local transmission or by importation is critical in the implementation of an effective plan of action in the country. This new era emphasizes the global nature of regional malaria elimination. Increasing global surveillance and tool development are necessary in order to "fingerprint" parasites and identify their origin.
Collapse
Affiliation(s)
- Sharmini Gunawardena
- Department of Parasitology, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo 8, Sri Lanka
| | - Rachel F Daniels
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Infectious Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Thishan C Yahathugoda
- Department of Parasitology, Faculty of Medicine, University of Ruhuna, Karapitiya, Galle, Sri Lanka
| | - Mirani V Weerasooriya
- Department of Parasitology, Faculty of Medicine, University of Ruhuna, Karapitiya, Galle, Sri Lanka
| | - Katelyn Durfee
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Sarah K Volkman
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Infectious Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA, USA.,School of Nursing and Health Science, Simmons College, Boston, MA, USA
| | - Dyann F Wirth
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Infectious Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Nadira D Karunaweera
- Department of Parasitology, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo 8, Sri Lanka.
| |
Collapse
|
138
|
Groger M, Fischer HS, Veletzky L, Lalremruata A, Ramharter M. A systematic review of the clinical presentation, treatment and relapse characteristics of human Plasmodium ovale malaria. Malar J 2017; 16:112. [PMID: 28284211 PMCID: PMC5346189 DOI: 10.1186/s12936-017-1759-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/28/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Despite increased efforts to control and ultimately eradicate human malaria, Plasmodium ovale malaria is for the most part outside the focus of research or public health programmes. Importantly, the understanding of P. ovale-nowadays regarded as the two distinct species P. ovale wallikeri and P. ovale curtisi-largely stems from case reports and case series lacking study designs providing high quality evidence. Consecutively, there is a lack of systematic evaluation of the clinical presentation, appropriate treatment and relapse characteristics of P. ovale malaria. The aim of this systematic review is to provide a systematic appraisal of the current evidence for severe manifestations, relapse characteristics and treatment options for human P. ovale malaria. METHODS AND RESULTS This systematic review was performed according to the PRISMA guidelines and registered in the international prospective register for systematic reviews (PROSPERO 2016:CRD42016039214). P. ovale mono-infection was a strict inclusion criterion. Of 3454 articles identified by the literature search, 33 articles published between 1922 and 2015 met the inclusion criteria. These articles did not include randomized controlled trials. Five prospective uncontrolled clinical trials were performed on a total of 58 participants. P. ovale was sensitive to all tested drugs within the follow-up periods and on interpretable in vitro assays. Since its first description in 1922, only 18 relapsing cases of P. ovale with a total of 28 relapse events were identified in the scientific literature. There was however no molecular evidence for a causal relationship between dormant liver stages and subsequent relapses. A total of 22 severe cases of P. ovale malaria were published out of which five were fatal. Additionally, two cases of congenital P. ovale malaria were reported. CONCLUSIONS Current knowledge of P. ovale malaria is based on small trials with minor impact, case reports and clinical observations. This systematic review highlights that P. ovale is capable of causing severe disease, severe congenital malaria and may even lead to death. Evidence for relapses in patients with P. ovale malaria adds up to only a handful of cases. Nearly 100 years after P. ovale's first description by Stephens the evidence for the clinical characteristics, relapse potential and optimal treatments for P. ovale malaria is still scarce.
Collapse
Affiliation(s)
- Mirjam Groger
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Hannah S. Fischer
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Luzia Veletzky
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | | | - Michael Ramharter
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University of Vienna, Vienna, Austria
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany
| |
Collapse
|
139
|
Selective Whole-Genome Amplification Is a Robust Method That Enables Scalable Whole-Genome Sequencing of Plasmodium vivax from Unprocessed Clinical Samples. mBio 2017; 8:mBio.02257-16. [PMID: 28174312 PMCID: PMC5296604 DOI: 10.1128/mbio.02257-16] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Whole-genome sequencing (WGS) of microbial pathogens from clinical samples is a highly sensitive tool used to gain a deeper understanding of the biology, epidemiology, and drug resistance mechanisms of many infections. However, WGS of organisms which exhibit low densities in their hosts is challenging due to high levels of host genomic DNA (gDNA), which leads to very low coverage of the microbial genome. WGS of Plasmodium vivax, the most widely distributed form of malaria, is especially difficult because of low parasite densities and the lack of an ex vivo culture system. Current techniques used to enrich P. vivax DNA from clinical samples require significant resources or are not consistently effective. Here, we demonstrate that selective whole-genome amplification (SWGA) can enrich P. vivax gDNA from unprocessed human blood samples and dried blood spots for high-quality WGS, allowing genetic characterization of isolates that would otherwise have been prohibitively expensive or impossible to sequence. We achieved an average genome coverage of 24×, with up to 95% of the P. vivax core genome covered by ≥5 reads. The single-nucleotide polymorphism (SNP) characteristics and drug resistance mutations seen were consistent with those of other P. vivax sequences from a similar region in Peru, demonstrating that SWGA produces high-quality sequences for downstream analysis. SWGA is a robust tool that will enable efficient, cost-effective WGS of P. vivax isolates from clinical samples that can be applied to other neglected microbial pathogens. Malaria is a disease caused by Plasmodium parasites that caused 214 million symptomatic cases and 438,000 deaths in 2015. Plasmodium vivax is the most widely distributed species, causing the majority of malaria infections outside sub-Saharan Africa. Whole-genome sequencing (WGS) of Plasmodium parasites from clinical samples has revealed important insights into the epidemiology and mechanisms of drug resistance of malaria. However, WGS of P. vivax is challenging due to low parasite levels in humans and the lack of a routine system to culture the parasites. Selective whole-genome amplification (SWGA) preferentially amplifies the genomes of pathogens from mixtures of target and host gDNA. Here, we demonstrate that SWGA is a simple, robust method that can be used to enrich P. vivax genomic DNA (gDNA) from unprocessed human blood samples and dried blood spots for cost-effective, high-quality WGS.
Collapse
|
140
|
Rutledge GG, Böhme U, Sanders M, Reid AJ, Cotton JA, Maiga-Ascofare O, Djimdé AA, Apinjoh TO, Amenga-Etego L, Manske M, Barnwell JW, Renaud F, Ollomo B, Prugnolle F, Anstey NM, Auburn S, Price RN, McCarthy JS, Kwiatkowski DP, Newbold CI, Berriman M, Otto TD. Plasmodium malariae and P. ovale genomes provide insights into malaria parasite evolution. Nature 2017; 542:101-104. [PMID: 28117441 PMCID: PMC5326575 DOI: 10.1038/nature21038] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 12/04/2016] [Indexed: 01/12/2023]
Abstract
Elucidation of the evolutionary history and interrelatedness of Plasmodium species that infect humans has been hampered by a lack of genetic information for three human-infective species: P. malariae and two P. ovale species (P. o. curtisi and P. o. wallikeri). These species are prevalent across most regions in which malaria is endemic and are often undetectable by light microscopy, rendering their study in human populations difficult. The exact evolutionary relationship of these species to the other human-infective species has been contested. Using a new reference genome for P. malariae and a manually curated draft P. o. curtisi genome, we are now able to accurately place these species within the Plasmodium phylogeny. Sequencing of a P. malariae relative that infects chimpanzees reveals similar signatures of selection in the P. malariae lineage to another Plasmodium lineage shown to be capable of colonization of both human and chimpanzee hosts. Molecular dating suggests that these host adaptations occurred over similar evolutionary timescales. In addition to the core genome that is conserved between species, differences in gene content can be linked to their specific biology. The genome suggests that P. malariae expresses a family of heterodimeric proteins on its surface that have structural similarities to a protein crucial for invasion of red blood cells. The data presented here provide insight into the evolution of the Plasmodium genus as a whole.
Collapse
Affiliation(s)
- Gavin G Rutledge
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Ulrike Böhme
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Mandy Sanders
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Adam J Reid
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - James A Cotton
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Oumou Maiga-Ascofare
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako BP E.2528, Mali
- German Center for Infection Research, 20359 Hamburg, Germany
| | - Abdoulaye A Djimdé
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako BP E.2528, Mali
| | - Tobias O Apinjoh
- University of Buea, Post Office Box 63, Buea, South West Region, Republic of Cameroon
| | - Lucas Amenga-Etego
- Navrongo Health Research Centre, Post Office Box 114, Navrongo, Upper East Region, Ghana
| | - Magnus Manske
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - John W Barnwell
- Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
| | - François Renaud
- Laboratoire MIVEGEC (UM1-CNRS-IRD), 34394 Montpellier, France
| | - Benjamin Ollomo
- Centre International de Recherches Médicales de Franceville, BP 709 Franceville, Gabon
| | - Franck Prugnolle
- Laboratoire MIVEGEC (UM1-CNRS-IRD), 34394 Montpellier, France
- Centre International de Recherches Médicales de Franceville, BP 709 Franceville, Gabon
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory 0810, Australia
| | - Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory 0810, Australia
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory 0810, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - James S McCarthy
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, University of Queensland, Brisbane, Queensland 4006, Australia
| | - Dominic P Kwiatkowski
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Chris I Newbold
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Matthew Berriman
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| |
Collapse
|
141
|
The Rheopathobiology of Plasmodium vivax and Other Important Primate Malaria Parasites. Trends Parasitol 2016; 33:321-334. [PMID: 28040374 DOI: 10.1016/j.pt.2016.11.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/17/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022]
Abstract
Our current understanding of how malaria parasites remodel their host red blood cells (RBCs) and ultimately cause disease is largely based on studies of Plasmodium falciparum. In this review, we expand our knowledge to include what is currently known about pathophysiological changes to RBCs that are infected by non-falciparum malaria parasites. We highlight the potential folly of making generalizations about the rheology of malaria infection, and emphasize the need for more systematic studies into the erythrocytic biology of non-falciparum malaria parasites. We propose that a better understanding of the mechanisms that underlie the changes to RBCs induced by malaria parasites other than P. falciparum may be highly informative for the development of therapeutics that specifically disrupt the altered rheological profile of RBCs infected with either sexual- or asexual-stage parasites, resulting in drugs that block transmission, reduce disease severity, and help delay the onset of resistance to current and future anti-malaria drugs.
Collapse
|
142
|
Abstract
Parasites of medical importance have long been classified taxonomically by morphological characteristics. However, molecular-based techniques have been increasingly used and relied on to determine evolutionary distances for the basis of rational hierarchal classifications. This has resulted in several different classification schemes for parasites and changes in parasite taxonomy. The purpose of this Minireview is to provide a single reference for diagnostic laboratories that summarizes new and revised clinically relevant parasite taxonomy from January 2012 through December 2015.
Collapse
|
143
|
Avian and simian malaria: do they have a cancer connection? Parasitol Res 2016; 116:839-845. [DOI: 10.1007/s00436-016-5352-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 12/11/2016] [Indexed: 12/31/2022]
|
144
|
Zaw MT, Lin Z. Two sympatric types of Plasmodium ovale and discrimination by molecular methods. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2016; 50:559-564. [PMID: 28065415 DOI: 10.1016/j.jmii.2016.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 10/29/2015] [Accepted: 08/15/2016] [Indexed: 12/01/2022]
Abstract
Plasmodium ovale is widely distributed in tropical countries, whereas it has not been reported in the Americas. It is not a problem globally because it is rarely detected by microscopy owing to low parasite density, which is a feature of clinical ovale malaria. P.o. curtisi and P.o. wallikeri are widespread in both Africa and Asia, and were known to be sympatric in many African countries and in southeast Asian countries. Small subunit ribosomal RNA (SSUrRNA) gene, cytochrome b (cytb) gene, and merozoite surface protein-1 (msp-1) gene were initially studied for molecular discrimination of P.o. curtisi and P.o. wallikeri using polymerase chain reaction (PCR) and DNA sequencing. DNA sequences of other genes from P. ovale in Southeast Asia and the southwestern Pacific regions were also targeted to differentiate the two sympatric types. In terms of clinical manifestations, P.o. wallikeri tended to produce higher parasitemia levels and more severe symptoms. To date, there have been a few studies that used the quantitative PCR method for discrimination of the two distinct P. ovale types. Conventional PCR with consequent DNA sequencing is the common method used to differentiate these two types. It is necessary to identify these two types because relapse periodicity, drug susceptibility, and mosquito species preference need to be studied to reduce ovale malaria. In this article, an easier method of molecular-level discrimination of P.o. curtisi and P.o. wallikeri is proposed.
Collapse
Affiliation(s)
- Myo Thura Zaw
- Department of Pathobiological and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Zaw Lin
- Department of Pathobiological and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia.
| |
Collapse
|
145
|
Li P, Zhao Z, Xing H, Li W, Zhu X, Cao Y, Yang Z, Sattabongkot J, Yan G, Fan Q, Cui L. Plasmodium malariae and Plasmodium ovale infections in the China-Myanmar border area. Malar J 2016; 15:557. [PMID: 27846879 PMCID: PMC5111346 DOI: 10.1186/s12936-016-1605-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/07/2016] [Indexed: 01/28/2023] Open
Abstract
Background The Greater Mekong Subregion is aiming to achieve regional malaria elimination by 2030. Though a shift in malaria parasite species predominance by Plasmodium vivax has been recently documented, the transmission of the two minor Plasmodium species, Plasmodium malariae and Plasmodium ovale spp., is poorly characterized in the region. This study aims to determine the prevalence of these minor species in the China–Myanmar border area and their genetic diversity. Methods Epidemiology study was conducted during passive case detection in hospitals and clinics in Myanmar and four counties in China along the China–Myanmar border. Cross-sectional surveys were conducted in villages and camps for internally displaced persons to determine the prevalence of malaria infections. Malaria infections were diagnosed initially by microscopy and later in the laboratory using nested PCR for the SSU rRNA genes. Plasmodium malariae and P. ovale infections were confirmed by sequencing the PCR products. The P. ovale subtypes were determined by sequencing the Pocytb, Pocox1 and Pog3p genes. Parasite populations were evaluated by PCR amplification and sequencing of the MSP-1 genes. Antifolate sensitivity was assessed by sequencing the dhfr-ts and dhps genes from the P. malariae and P. ovale isolates. Results Analysis of 2701 blood samples collected from the China–Myanmar border by nested PCR targeting the parasite SSU rRNA genes identified 561 malaria cases, including 161 Plasmodium falciparum, 327 P. vivax, 66 P. falciparum/P. vivax mixed infections, 4 P. malariae and 3 P. ovale spp. P. vivax and P. falciparum accounted for >60 and ~30% of all malaria cases, respectively. In comparison, the prevalence of P. malariae and P. ovale spp. was very low and only made up ~1% of all PCR-positive cases. Nevertheless, these two species were often misidentified as P. vivax infections or completely missed by microscopy even among symptomatic patients. Phylogenetic analysis of the SSU rRNA, Pocytb, Pocox1 and Pog3p genes confirmed that the three P. ovale spp. isolates belonged to the subtype P. ovale curtisi. Low-level genetic diversity was detected in the MSP-1, dhfr and dhps genes of these minor parasite species, potentially stemming from the low prevalence of these parasites preventing their mixing. Whereas most of the dhfr and dhps positions equivalent to those conferring antifolate resistance in P. falciparum and P. vivax were wild type, a new mutation S113C corresponding to the S108 position in pfdhfr was identified in two P. ovale curtisi isolates. Conclusions The four human malaria parasite species all occurred sympatrically at the China–Myanmar border. While P. vivax has become the predominant species, the two minor parasite species also occurred at very low prevalence but were often misidentified or missed by conventional microscopy. These minor parasite species displayed low levels of polymorphisms in the msp-1, dhfr and dhps genes. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1605-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Peipei Li
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Zhenjun Zhao
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Hua Xing
- Dalian University of Technology, Dalian, Liaoning, China
| | - Wenli Li
- Dalian University of Technology, Dalian, Liaoning, China
| | - Xiaotong Zhu
- Department of Immunology, China Medical University, Shenyang, Liaoning, China
| | - Yaming Cao
- Department of Immunology, China Medical University, Shenyang, Liaoning, China
| | - Zhaoqing Yang
- Department of Parasitology, Kunming Medical University, Kunming, Yunnan, China
| | | | - Guiyun Yan
- University of California, Irvine, CA, USA
| | - Qi Fan
- Dalian Institute of Biotechnology, Dalian, Liaoning, China.
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park, PA, USA.
| |
Collapse
|
146
|
Phuong MS, Lau R, Ralevski F, Boggild AK. Parasitological correlates of Plasmodium ovale curtisi and Plasmodium ovale wallikeri infection. Malar J 2016; 15:550. [PMID: 27832785 PMCID: PMC5103354 DOI: 10.1186/s12936-016-1601-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 11/04/2016] [Indexed: 11/10/2022] Open
Abstract
Background Malaria, due to Plasmodium ovale, can be challenging to diagnose due to clinically mild disease and low parasite burden. Two genetically distinct sub-species of P. ovale exist: Plasmodium ovale curtisi (classic) and Plasmodium ovale wallikeri (variant). It is presently unknown if the sub-species causing infection affects performance of malaria diagnostic tests. The aim of this work was to understand how the genetically distinct sub-species, P. o. curtisi and P. o. wallikeri, affect malaria diagnostic tests. Methods Plasmodium ovale-positive whole blood specimens were sub-speciated by PCR and sequencing of 18S rRNA and dhfr-ts. Parasitaemia, morphology, pan-aldolase positivity, 18S copy number, and dhfr-ts sequences were compared between sub-species. Results From 2006 to 2015, 49 P. ovale isolates were identified, of which 22 were P. o. curtisi and 27 P. o. wallikeri; 80% were identified in the last five years, and 88% were acquired in West Africa. Sub-species did not differ by parasitaemia, 18S copy number, or pan-aldolase positivity. Lack of Schüffner’s stippling was over-represented among P. o. wallikeri isolates (p = 0.02). Several nucleotide polymorphisms between the sub-species were observed, but they do not occur at sites believed to relate to antifolate binding. Conclusions Plasmodium ovale is increasing among travellers to West Africa, although sub-species do not differ significantly by parasitologic features such as parasitaemia. Absence of Schüffner’s stippling may be a feature specific to P. o. wallikeri and is a novel finding.
Collapse
Affiliation(s)
| | - Rachel Lau
- Public Health Ontario Laboratories, Toronto, Canada
| | | | - Andrea K Boggild
- Public Health Ontario Laboratories, Toronto, Canada. .,Tropical Disease Unit, Division of Infectious Diseases, Toronto General Hospital, University Health Network, 200 Elizabeth Street, 13EN-218, Toronto, ON, M5G 2C4, Canada. .,University of Toronto, Toronto, Canada.
| |
Collapse
|
147
|
Auburn S, Barry AE. Dissecting malaria biology and epidemiology using population genetics and genomics. Int J Parasitol 2016; 47:77-85. [PMID: 27825828 DOI: 10.1016/j.ijpara.2016.08.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 08/09/2016] [Accepted: 08/25/2016] [Indexed: 10/20/2022]
Abstract
Molecular approaches have an increasingly recognized utility in surveillance of malaria parasite populations, not only in defining prevalence and incidence with higher sensitivity than traditional methods, but also in monitoring local and regional parasite transmission patterns. In this review, we provide an overview of population genetic and genomic studies of human-infecting Plasmodium species, highlighting recent advances in the field. In accordance with the renewed impetus for malaria eradication, many studies are now using genetic and genomic epidemiology to support local evidence-based intervention strategies. Microsatellite genotyping remains a popular approach for both Plasmodium falciparum and Plasmodium vivax. However, with the increasing availability of whole genome sequencing data enabling effective single nucleotide polymorphism-based panels tailored to a given study question and setting, this approach is gaining popularity. The availability of new reference genomes for Plasmodium malariae and Plasmodium ovale should see a surge in similar molecular studies on these currently neglected species. Genomic studies are revealing new insights into important adaptive mechanisms of the parasite including antimalarial drug resistance. The advent of new methodologies such as selective whole genome amplification for dealing with extensive human DNA in low density field isolates should see genome-wide approaches becoming routine for parasite surveillance once the economic costs outweigh the current cost benefits of targeted approaches.
Collapse
Affiliation(s)
- Sarah Auburn
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
| | - Alyssa E Barry
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Australia.
| |
Collapse
|
148
|
Cao Y, Wang W, Liu Y, Cotter C, Zhou H, Zhu G, Tang J, Tang F, Lu F, Xu S, Gu Y, Zhang C, Li J, Cao J. The increasing importance of Plasmodium ovale and Plasmodium malariae in a malaria elimination setting: an observational study of imported cases in Jiangsu Province, China, 2011-2014. Malar J 2016; 15:459. [PMID: 27604629 PMCID: PMC5015233 DOI: 10.1186/s12936-016-1504-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/26/2016] [Indexed: 11/27/2022] Open
Abstract
Background Following initiation of China’s National Malaria Elimination Action Plan in 2010, indigenous malaria infections in Jiangsu Province decreased significantly. Meanwhile imported Plasmodium infections have increased substantially, particularly Plasmodium ovale and Plasmodium malariae. Given the risk for malaria resurgence, there is an urgent need to understand the increase in imported P. ovale and P. malariae infections as China works to achieve national malaria elimination. Methods An observational study of imported malaria cases in Jiangsu Province, China was carried out for the period of 2011–2014. Results A total of 1268 malaria cases were reported in Jiangsu Province from 2011 to 2014. Although imported Plasmodium falciparum cases (n = 1058) accounted for 83.4 % of all reported cases in Jiangsu, P. ovale cases (14, 19, 30, and 46) and their proportion (3.7, 9.6, 8.8, and 13.0 %) of all malaria cases increased over the 4 years. Similarly, P. malariae cases (seven, two, nine, and 10) and proportion (1.9, 1.0, 2.6, and 2.8 %) of all malaria cases increased slightly during this time. A total of 98 cases of Plasmodium ovale curtisi (47/98, 48 %) and Plasmodium ovale wallikeri (51/98, 52 %) were identified as well. Latency periods were significant among these Plasmodium infections (p = 0.00). Also, this study found that the latency periods of P. ovale sp., P. malariae and Plasmodium vivax were significantly longer than P. falciparum. However, for both P. ovale curtisi and P. ovale wallikeri infections, the latency period analysis was not significant (p = 0.81). Misdiagnosis of both P. ovale and P. malariae was greater than 71.5 and 71.4 %, respectively. The P. ovale cases were misdiagnosed as P. falciparum (35 cases, 32.1 %), P. vivax (43 cases, 39.4 %) by lower levels of CDCs or hospitals. And, the P. malariae cases were misdiagnosed as P. falciparum (ten cases, 35.7 %), P. vivax (nine cases, 32.1 %) and P. ovale sp. (one case, 3.6 %). Geographic distribution of imported P. ovale sp. and P. malariae cases in Jiangsu Province mainly originated from sub-Saharan Africa such as Equatorial Guinea, Nigeria, and Angola. Conclusions Although the vast majority of imported malaria cases were due to P. falciparum, the increase in other rare Plasmodium species originating from sub-Saharan Africa and Southeast Asia should be closely monitored at all levels of health providers focusing on diagnosis and treatment of malaria. In addition to a receptive vector environment, long latency periods and misdiagnosis of P. malariae and P. ovale sp. increase the risk of re-introduction of malaria in China.
Collapse
Affiliation(s)
- Yuanyuan Cao
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Weiming Wang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Yaobao Liu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Chris Cotter
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Huayun Zhou
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Guoding Zhu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Jianxia Tang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Feng Tang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Feng Lu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Sui Xu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Yaping Gu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Chao Zhang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Julin Li
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China
| | - Jun Cao
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, Jiangsu, People's Republic of China. .,Public Health Research Center, Jiangnan University, Wuxi, 214122, Jiangsu, People's Republic of China.
| |
Collapse
|
149
|
Non-falciparum malaria in Dakar: a confirmed case of Plasmodium ovale wallikeri infection. Malar J 2016; 15:429. [PMID: 27557982 PMCID: PMC4997729 DOI: 10.1186/s12936-016-1485-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 08/11/2016] [Indexed: 11/15/2022] Open
Abstract
Background Plasmodium ovale is rarely described in Senegal. A case of clinical malaria due to P. ovale wallikeri in West Central of Senegal is reported. Case A 34-year-old male baker in Dakar, with no significant previous medical history, was admitted to a health clinic with fever and vomiting. Fever had been lasting for 4 days with peaks every 48 h. As monospecific Plasmodium falciparum HRP-2 RDT was negative, he was treated with antibiotics. However, owing to persisting symptoms, he was referred to the emergency unit of the Youssou Mbargane Diop Hospital, Dakar, Senegal. Clinical examination found impaired general condition. All other physical examinations were normal. Laboratory tests showed anaemia (haemoglobin 11.4 g/dl), severe thrombocytopaenia (platelets 30 × 109/mm3), leukopenia (3650/mm3), lymphocytopenia (650/mm3). Renal function was normal as indicated by creatininaemia and uraemia (11 mg/l and 0.25 g/l, respectively) and liver enzymes were slightly elevated (aspartate aminotransferase 77 UI/l and alanine aminotransferase 82 UI/l). Blood smear evaluations in Parasitology Laboratory of Aristide Le Dantec Hospital showed malaria parasites of the species P. ovale with a 0.08 % parasitaemia. Molecular confirmation was done by real time PCR targeting the 18S rRNA gene. The P. ovale infection was further analysed to species level targeting the potra gene and was identified as P. ovale wallikeri. According to the hospital’s malaria treatment guidelines for severe malaria, treatment consisted of intravenous quinine at hour 0 (start of treatment) and 24 h after initial treatment, followed by artemether–lumefantrine 24 h later. A negative microscopy was noted on day 3 post-treatment and the patient reported no further symptoms. Conclusion Malaria due to non-falciparum species is probably underestimated in Senegal. RDTs specific to non-falciparum species and/or pan specific RDTs should be included as tools of diagnosis to fight against malaria in Senegal. In addition, a field-deployable molecular tool such as the loop-mediated isothermal amplification can be considered as an additional useful tool to detect low malaria parasite infections and for speciation. In addition, national malaria control policies should consider other non-falciparum species in treatment guidelines, including the provision of primaquine for the treatment of relapsing parasites.
Collapse
|
150
|
Sutherland CJ. Persistent Parasitism: The Adaptive Biology of Malariae and Ovale Malaria. Trends Parasitol 2016; 32:808-819. [PMID: 27480365 DOI: 10.1016/j.pt.2016.07.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/17/2016] [Accepted: 07/12/2016] [Indexed: 12/29/2022]
Abstract
Plasmodium malariae causes malaria in humans throughout the tropics and subtropics. Plasmodium ovale curtisi and Plasmodium ovale wallikeri are sympatric sibling species common in sub-Saharan Africa and also found in Oceania and Asia. Although rarely identified as the cause of malaria cases in endemic countries, PCR detection has confirmed all three parasite species to be more prevalent, and persistent, than previously thought. Chronic, low-density, multispecies asymptomatic infection is a successful biological adaptation by these Plasmodium spp., a pattern also observed among malaria parasites of wild primates. Current whole-genome analyses are illuminating the species barrier separating the ovale parasite species and reveal substantial expansion of subtelomeric gene families. The evidence for and against a quiescent pre-erythrocytic form of P. malariae is reviewed.
Collapse
Affiliation(s)
- Colin J Sutherland
- Department of Immunology and Infection and Public Health England Malaria Reference Laboratory, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; Department of Clinical Parasitology, Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, Mortimer Market Centre, Capper Street, London WC1E 6JB, UK.
| |
Collapse
|