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Quaye IK, Aleksenko L, Paganotti GM, Peloewetse E, Haiyambo DH, Ntebela D, Oeuvray C, Greco B. Malaria Elimination in Africa: Rethinking Strategies for Plasmodium vivax and Lessons from Botswana. Trop Med Infect Dis 2023; 8:392. [PMID: 37624330 PMCID: PMC10458071 DOI: 10.3390/tropicalmed8080392] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/21/2023] [Accepted: 07/22/2023] [Indexed: 08/26/2023] Open
Abstract
The global malaria community has picked up the theme of malaria elimination in more than 90% of the world's population in the next decade. Recent reports of Plasmodium vivax (P. vivax) in sub-Saharan Africa, including in Duffy-negative individuals, threaten the efforts aimed at achieving elimination. This is not only in view of strategies that are tailored only to P. falciparum elimination but also due to currently revealed biological characteristics of P. vivax concerning the relapse patterns of hypnozoites and conservation of large biomasses in cryptic sites in the bone marrow and spleen. A typical scenario was observed in Botswana between 2008 and 2018, which palpably projects how P. vivax could endanger malaria elimination efforts where the two parasites co-exist. The need for the global malaria community, national malaria programs (NMPs), funding agencies and relevant stakeholders to engage in a forum to discuss and recommend clear pathways for elimination of malaria, including P. vivax, in sub-Saharan Africa is warranted.
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Affiliation(s)
- Isaac K. Quaye
- Pan African Vivax and Ovale Network, Faculty of Engineering Computer and Allied Sciences, Regent University College of Science and Technology, #1 Regent Ave, McCarthy Hill, Mendskrom, Dansoman, Accra P.O. Box DS1636, Ghana
| | - Larysa Aleksenko
- Department of Health Sciences, School of Public Health, College of Health, Medicine and Life Sciences, Brunel University, Kingston Lane, Uxbridge, Middlesex, London UB8 3PH, UK;
| | - Giacomo M. Paganotti
- Botswana-University of Pennsylvania Partnership, Riverwalk, Gaborone P.O. Box 45498, Botswana;
- Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elias Peloewetse
- Department of Biological Sciences, Faculty of Sciences, University of Botswana, Gaborone Private Bag 00704, Botswana;
| | - Daniel H. Haiyambo
- Department of Human, Biological and Translational Medical Sciences, Faculty of Health Sciences and Veterinary Medicine, University of Namibia School of Medicine, Hage Geingob Campus, Windhoek Private Bag 13301, Namibia;
| | - Davies Ntebela
- National Malaria Program, Ministry of Health, Gaborone Private Bag 0038, Botswana;
| | - Claude Oeuvray
- Global Health Institute of Merck, Terre Bonne Building Z0, Route de Crassier 1, Eysin, 1266 Geneva, Switzerland; (C.O.); (B.G.)
| | - Beatrice Greco
- Global Health Institute of Merck, Terre Bonne Building Z0, Route de Crassier 1, Eysin, 1266 Geneva, Switzerland; (C.O.); (B.G.)
| | - the PAVON Consortium
- PAVON, Regent University College of Science and Technology, #1 Regent Avenue, McCarthy Hiil, Mendskrom, Dansoman, Accra P.O. Box DS1636, Ghana
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African Plasmodium vivax malaria improbably rare or benign. Trends Parasitol 2022; 38:683-696. [PMID: 35667992 DOI: 10.1016/j.pt.2022.05.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/10/2022] [Accepted: 05/10/2022] [Indexed: 11/23/2022]
Abstract
The overwhelming dominance of Duffy blood group negativity among most people living in sub-Saharan Africa has been considered the basis of their protection from endemic Plasmodium vivax malaria. New evidence demonstrates widespread transmission of P. vivax in Duffy-negative Africa, though currently of unknown distribution, magnitude, or consequences. Other new evidence from outside of Africa demonstrates marked tropisms of P. vivax for extravascular tissues of bone marrow and spleen. Those establish states of proliferative infection with low-grade or undetectable parasitemia of peripheral blood causing acute and chronic disease. This review examines the plausibility of those infectious processes also operating in Duffy-negative Africans and causing harm of unrecognized origin.
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Fuehrer HP, Campino S, Sutherland CJ. The primate malaria parasites Plasmodium malariae, Plasmodium brasilianum and Plasmodium ovale spp.: genomic insights into distribution, dispersal and host transitions. Malar J 2022; 21:138. [PMID: 35505317 PMCID: PMC9066925 DOI: 10.1186/s12936-022-04151-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/05/2022] [Indexed: 01/04/2023] Open
Abstract
During the twentieth century, there was an explosion in understanding of the malaria parasites infecting humans and wild primates. This was built on three main data sources: from detailed descriptive morphology, from observational histories of induced infections in captive primates, syphilis patients, prison inmates and volunteers, and from clinical and epidemiological studies in the field. All three were wholly dependent on parasitological information from blood-film microscopy, and The Primate Malarias” by Coatney and colleagues (1971) provides an overview of this knowledge available at that time. Here, 50 years on, a perspective from the third decade of the twenty-first century is presented on two pairs of primate malaria parasite species. Included is a near-exhaustive summary of the recent and current geographical distribution for each of these four species, and of the underlying molecular and genomic evidence for each. The important role of host transitions in the radiation of Plasmodium spp. is discussed, as are any implications for the desired elimination of all malaria species in human populations. Two important questions are posed, requiring further work on these often ignored taxa. Is Plasmodium brasilianum, circulating among wild simian hosts in the Americas, a distinct species from Plasmodium malariae? Can new insights into the genomic differences between Plasmodium ovale curtisi and Plasmodium ovale wallikeri be linked to any important differences in parasite morphology, cell biology or clinical and epidemiological features?
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Affiliation(s)
- Hans-Peter Fuehrer
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria
| | - Susana Campino
- Department of Infection Biology, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Colin J Sutherland
- Department of Infection Biology, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
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Sarkar R, Kessler A, Mawkhlieng B, Sullivan SA, Wilson ML, Carlton JM, Albert S. Household and individual level risk factors associated with declining malaria incidence in Meghalaya, India: implications for malaria elimination in low-endemic settings. Malar J 2021; 20:460. [PMID: 34895233 PMCID: PMC8665616 DOI: 10.1186/s12936-021-03982-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 11/12/2021] [Indexed: 01/02/2023] Open
Abstract
Background A detailed analysis of household and individual level Plasmodium infection patterns in two low-endemic districts of Meghalaya was undertaken to better understand the epidemiology of malaria in northeast India. Methods Socio-demographic and behavioural information from residents (aged 1–69 years) of households were collected through pre-tested, questionnaire conducted in 2018 and 2019. Blood samples collected from participants were tested for Plasmodium falciparum and/or Plasmodium vivax infection using rapid diagnostic test, microscopy and PCR. Plasma samples from a subset of participants were analysed for antibodies against thirteen P. falciparum and four P. vivax antigens. Associations between household and individual level risk factors, and Plasmodium infections were evaluated using multilevel logistic regression models. Results A total of 2753 individuals from 827 households were enrolled in 2018, and 834 individuals from 222 households were enrolled in 2019. Of them, 33 (1.2%) were positive by PCR for P. falciparum in 2018 and none were positive for P. vivax. In 2019, no PCR-positive individuals were detected. All, but one, infections were asymptomatic; all 33 infections were sub-microscopic. Reported history of malaria in the past 12 months (OR = 8.84) and history of travel in the past 14 days (OR = 10.06) were significantly associated with Plasmodium infection. A significant trend of increased seropositivity with age was noted for all 17 antigens. Although adults (≥ 18 years) consistently had the highest seropositivity rates, a sizeable proportion of under-five children were also found to be seropositive. Almost all individuals (99.4%) reported sleeping under an insecticide-treated bed-net, and household indoor residual spray coverage in the 12 months preceding the survey was low (23%). Most participants correctly identified common signs and symptoms of malaria, i.e., fever (96.4%), headache (71.2%), chills (83.2%) and body-ache (61.8%). Almost all participants (94.3%) used government-provided services for treatment of malaria. Conclusion This study explored the epidemiology of malaria in two communities in Meghalaya, India, in the context of declining transmission. The presence of widespread asymptomatic infections and seropositivity among under-five children suggest that low-level Plasmodium transmission persists in this region. Implications of the study findings for malaria elimination efforts in low-transmission settings are discussed.
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Affiliation(s)
- Rajiv Sarkar
- Indian Institute of Public Health - Shillong, Shillong, Meghalaya, 793001, India. .,Martin Luther Christian University, Shillong, Meghalaya, 793006, India.
| | - Anne Kessler
- 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
| | - Mark L Wilson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Jane M Carlton
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, 10003, USA.,Department of Epidemiology, School of Global Public Health, New York University, New York, NY, 10003, USA
| | - Sandra Albert
- Indian Institute of Public Health - Shillong, Shillong, Meghalaya, 793001, India.,Martin Luther Christian University, Shillong, Meghalaya, 793006, India
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The Pan African Vivax and Ovale Network (PAVON): Refocusing on Plasmodium vivax, ovale and asymptomatic malaria in sub-Saharan Africa. Parasitol Int 2021; 84:102415. [PMID: 34216801 DOI: 10.1016/j.parint.2021.102415] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 11/20/2022]
Abstract
The recent World Malaria report shows that progress in malaria elimination has stalled. Current data acquisition by NMCPs depend on passive case detection and clinical reports focused mainly on Plasmodium falciparum (Pf). In recent times, several countries in sub-Saharan Africa have reported cases of Plasmodium vivax (Pv) with a considerable number being Duffy negative. The burden of Pv and Plasmodium ovale (Po) appear to be more than acknowledged. Similarly, the contribution of asymptomatic malaria in transmission is hardly considered by NMCPs in Africa. Inclusion of these as targets in malaria elimination agenda is necessary to achieve elimination goal, as these harbor hypnozoites. The Pan African Vivax and Ovale Network (PAVON) is a new consortium of African Scientists working in Africa on the transmission profile of Pv and Po. The group collaborates with African NMCPs to train in Plasmodium molecular diagnostics, microscopy, and interpretation of molecular data from active surveys to translate into policy. Details of the mission, rational and modus operandi of the group are outlined.
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