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Ngou CM, Bayibéki AN, Abate L, Makinde OS, Feufack-Donfack LB, Sarah-Matio EM, Bouopda-Tuedom AG, Taconet P, Moiroux N, Awono-Ambéné PH, Talman A, Ayong LS, Berry A, Nsango SE, Morlais I. Influence of the sickle cell trait on Plasmodium falciparum infectivity from naturally infected gametocyte carriers. BMC Infect Dis 2023; 23:317. [PMID: 37165325 PMCID: PMC10173526 DOI: 10.1186/s12879-023-08134-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 03/03/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Sickle cell trait (SCT) refers to the carriage of one abnormal copy of the β-globin gene, the HbS allele. SCT offers protection against malaria, controlling parasite density and preventing progression to symptomatic malaria. However, it remains unclear whether SCT also affects transmission stages and mosquito infection parameters. Deciphering the impact of the SCT on human to mosquito malaria transmission is key to understanding mechanisms that maintain the trait in malaria endemic areas. METHODS The study was conducted from June to July 2017 among asymptomatic children living in the locality of Mfou, Cameroon. Blood samples were collected from asymptomatic children to perform malaria diagnosis by microscopy, Plasmodium species by PCR and hemoglobin typing by RFLP. Infectiousness of gametocytes to mosquitoes was assessed by membrane feeding assays using blood from gametocyte carriers of HbAA and HbAS genotypes. A zero-inflated model was fitted to predict distribution of oocysts in mosquitoes according to hemoglobin genotype of the gametocyte source. RESULTS Among the 1557 children enrolled in the study, 314 (20.16%) were of the HbAS genotype. The prevalence of children with P. falciparum gametocytes was 18.47% in HbAS individuals and 13.57% in HbAA, and the difference is significant (χ2 = 4.61, P = 0.032). Multiplicity of infection was lower in HbAS gametocyte carriers (median = 2 genotypes/carrier in HbAS versus 3.5 genotypes/carrier in HbAA, Wilcoxon sum rank test = 188, P = 0.032). Gametocyte densities in the blood donor significantly influenced mosquito infection prevalence in both HbAS and HbAA individuals. The HbAS genotype had no significant effect on mosquito infection outcomes when using immune or naïve serum in feeding assays. In AB replacement feeding experiments, the odds ratio of mosquito infection for HbAA blood as compared to HbAS was 0.56 (95% CI 0.29-1.10), indicating a twice higher risk of infection in mosquitoes fed on gametocyte-containing blood of HbAS genotype. CONCLUSION Plasmodium transmission stages were more prevalent in SCT individuals. This may reflect the parasite's enhanced investment in the sexual stage to increase their survival rate when asexual replication is impeded. The public health impact of our results points the need for intensive malaria control interventions in areas with high prevalence of HbAS. The similar infection parameters in feeding experiments where mosquitoes received the original serum from the blood donor indicated that immune responses to gametocyte surface proteins occur in both HbAS and HbAA individuals. The higher risk of infection in mosquitoes fed on HbAS blood depleted of immune factors suggests that changes in the membrane properties in HbAS erythrocytes may impact on the maturation process of gametocytes within circulating red blood cells.
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Affiliation(s)
- Christelle M Ngou
- Institut de Recherche pour le Développement, MIVEGEC, Univ. Montpellier, CNRS, IRD, 91 Avenue Agropolis, BP 64501, 34394, Montpellier, France
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | | | - Luc Abate
- Institut de Recherche pour le Développement, MIVEGEC, Univ. Montpellier, CNRS, IRD, 91 Avenue Agropolis, BP 64501, 34394, Montpellier, France
| | - Olesula S Makinde
- Department of Statistics, Federal University of Technology, P.M.B 704, Akure, Nigeria
| | | | - Elangwe M Sarah-Matio
- Institut de Recherche pour le Développement, MIVEGEC, Univ. Montpellier, CNRS, IRD, 91 Avenue Agropolis, BP 64501, 34394, Montpellier, France
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Aline G Bouopda-Tuedom
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- Department of Biological Sciences, Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, Douala, Cameroon
| | - Paul Taconet
- Institut de Recherche pour le Développement, MIVEGEC, Univ. Montpellier, CNRS, IRD, 91 Avenue Agropolis, BP 64501, 34394, Montpellier, France
| | - Nicolas Moiroux
- Institut de Recherche pour le Développement, MIVEGEC, Univ. Montpellier, CNRS, IRD, 91 Avenue Agropolis, BP 64501, 34394, Montpellier, France
| | | | - Arthur Talman
- Institut de Recherche pour le Développement, MIVEGEC, Univ. Montpellier, CNRS, IRD, 91 Avenue Agropolis, BP 64501, 34394, Montpellier, France
| | - Lawrence S Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Antoine Berry
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université Toulouse, CNRS UMR5051, INSERM UMR1291, UPS, Toulouse, France
- Service de Parasitologie_Mycologie, Centre Hospitalier Universitaire de Toulouse, Toulouse, France
| | - Sandrine E Nsango
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- Department of Biological Sciences, Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, Douala, Cameroon
| | - Isabelle Morlais
- Institut de Recherche pour le Développement, MIVEGEC, Univ. Montpellier, CNRS, IRD, 91 Avenue Agropolis, BP 64501, 34394, Montpellier, France.
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2
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Abeje G, Gelaye W, Alemu G. Comparison of capillary, venous and buffy coat blood samples in detecting Plasmodium species among malaria suspected patients attending at Hamusite health center. A cross-sectional study. BMC Infect Dis 2021; 21:576. [PMID: 34130649 PMCID: PMC8204542 DOI: 10.1186/s12879-021-06290-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 06/04/2021] [Indexed: 11/10/2022] Open
Abstract
Background Both capillary and venous blood samples have been interchangeably used for the diagnosis of malaria in Ethiopia. However, Plasmodium parasites are thought to be more concentrated in capillary than in venous blood. Hence, selecting a sample source where parasites are more concentrated is indispensable approach in order to maximize the accuracy of blood film microscopy. Therefore, the present study aimed to compare the detection rate and the parasitemia level of Plasmodium species from conventional capillary and venous blood films, and buffy coat preparations. Methods A facility based cross-sectional study was conducted from Feburary to March 2020 among 210 febrile patients attending Hamusite health center, northwest Ethiopia. Capillary and venous blood samples were collected and buffy coat was prepared from each sample. Thin and thick blood films were prepared, stained, and examined microscopically following standard protocol. Data were analysed using Statistical Package for Social Sciences Software version 20 and Med-Calc software version 19.3. Results Capillary blood buffy coat (61/210, 29.0%) had significantly higher detection rate as compared to capillary (48/210, 22.9%) and venous (42/210, 20.0%) blood films (p < 0.001). However, no significant difference was observed between capillary and venous blood films (p = 0.070) in detecting Plasmodium species. The highest and the lowest mean asexual stage parasite counts were found in capillary blood buffy coat (4692.88) and venous blood (631.43) films, respectively showing significant variations (p < 0.001). Mean gametocyte count was also highest in capillary blood buffy coat (3958.44). As compared to capillary blood buffy coat, the sensitivity of venous blood buffy coat, capillary blood film and venous blood film were 73.8, 78.7, 68.9%, respectively. Conclusion Capillary blood buffy coat samples showed the highest sensitivity in detecting and quantitating malaria parasites that its use should be promoted in clinical settings. However, conventional capillary and venous blood films could be used interchangeably.
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Affiliation(s)
- Getu Abeje
- Department of Biomedcal Science, Samara University, Samara, Ethiopia
| | - Woyneshet Gelaye
- Department of Medical Laboratory Science, Bahir Dar University, Bahir Dar, Ethiopia
| | - Getaneh Alemu
- Department of Medical Laboratory Science, Bahir Dar University, Bahir Dar, Ethiopia.
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3
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Leski TA, Taitt CR, Bangura U, Lahai J, Lamin JM, Baio V, Koroma MS, Swaray AG, Jacobsen KH, Jackson O, Jones BW, Phillips CL, Ansumana R, Stenger DA. Comparison of capillary and venous blood for malaria detection using two PCR-based assays in febrile patients in Sierra Leone. Malar J 2021; 20:133. [PMID: 33676502 PMCID: PMC7936501 DOI: 10.1186/s12936-021-03644-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 11/17/2022] Open
Abstract
Background Rapid and sensitive diagnostics are critical tools for clinical case management and public health control efforts. Both capillary and venous blood are currently used for malaria detection and while diagnostic technologies may not be equally sensitive with both materials, the published data on this subject are scarce and not conclusive. Methods Paired clinical samples of venous and capillary blood from 141 febrile individuals in Bo, Sierra Leone, were obtained between January and May 2019 and tested for the presence of Plasmodium parasites using two multiplexed PCR assays: the FilmArray-based Global Fever Panel (GFP) and the TaqMan-based Malaria Multiplex Sample Ready (MMSR) assay. Results No significant differences in Plasmodium parasite detection between capillary and venous blood for both assays were observed. The GFP assay was more sensitive than MMSR for all markers that could be compared (Plasmodium spp. and Plasmodium falciparum) in both venous and capillary blood. Conclusions No difference was found in malaria detection between venous and capillary blood using two different PCR-based detection assays. This data gives support for use of capillary blood, a material which can be obtained easier by less invasive methods, for PCR-based malaria diagnostics, independent of the platform.
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Affiliation(s)
- Tomasz A Leski
- Center for Bio/Molecular Science & Engineering, U.S. Naval Research Laboratory, Washington, DC, USA.
| | - Chris Rowe Taitt
- Center for Bio/Molecular Science & Engineering, U.S. Naval Research Laboratory, Washington, DC, USA
| | - Umaru Bangura
- Mercy Hospital Research Laboratory, Bo, Sierra Leone
| | - Joseph Lahai
- Mercy Hospital Research Laboratory, Bo, Sierra Leone
| | | | - Victoria Baio
- Mercy Hospital Research Laboratory, Bo, Sierra Leone
| | | | - Abdulai G Swaray
- College of Science, George Mason University, Fairfax, Virginia, USA
| | - Kathryn H Jacobsen
- Department of Global & Community Health, George Mason University, Fairfax, Virginia, USA
| | | | | | | | - Rashid Ansumana
- Mercy Hospital Research Laboratory, Bo, Sierra Leone.,Njala University, Bo, Sierra Leone
| | - David A Stenger
- Center for Bio/Molecular Science & Engineering, U.S. Naval Research Laboratory, Washington, DC, USA
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4
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Gorret AM, Muhindo R, Baguma E, Ntaro M, Mulogo EM, Deutsch-Feldman M, Juliano JJ, Nyehangane D, Boyce RM. Comparison of Capillary Versus Venous Blood for the Diagnosis of Plasmodium falciparum Malaria Using Rapid Diagnostic Tests. J Infect Dis 2021; 224:109-113. [PMID: 33502531 DOI: 10.1093/infdis/jiab032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/19/2021] [Indexed: 11/13/2022] Open
Abstract
We enrolled 250 febrile children in western Uganda to compare the results of malaria rapid diagnostic tests (RDTs) when using capillary vs venous blood. Participants were tested with 4 different RDT types. Polymerase chain reaction testing was performed as the reference standard. Sensitivity and specificity were broadly similar across RDT types and sampling method. Agreement between sample type was high, ranging from 0.95 to 0.99. When following the manufacturer's recommended interpretation, only 5 tests would have resulted in a different clinical diagnosis. These results demonstrate that malaria RDTs perform similarly when using capillary or venous blood in febrile children with Plasmodium falciparum malaria.
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Affiliation(s)
- Abalinda M Gorret
- Department of Medical Laboratory Science, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Rabbison Muhindo
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Emma Baguma
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Moses Ntaro
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Edgar M Mulogo
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Molly Deutsch-Feldman
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jonathan J Juliano
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Curriculum in Genetics and Microbiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Dan Nyehangane
- Department of Medical Laboratory Science, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda.,Epicentre Mbarara Research Centre, Mbarara, Uganda
| | - Ross M Boyce
- Department of Community Health, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda.,Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Mbohou Nchetnkou C, Nyabeyeu Nyabeyeu H, Kojom Foko LP, Lehman LG. Comparison of the fluorescence microscopy Cyscope® with light microscopy for malaria diagnosis in a small and active surveillance in Cameroon. Trop Med Health 2020; 48:61. [PMID: 32742185 PMCID: PMC7385968 DOI: 10.1186/s41182-020-00234-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/28/2020] [Indexed: 12/27/2022] Open
Abstract
Background Malaria has a negative impact on the activities of companies in endemic countries especially in Cameroon. In this regard, an increasingly growing number of companies have started to include management of malarious patients in their health policies. In the present study, we will evaluate the diagnostic performances of a fluorescence microscopy (FM), Cyscope® microscope, in the detection of malaria parasites. Methods A cross-sectional study was conducted among employees of two companies of the town of Douala on 21 and 22 March 2017. Sociodemographic information of employees was collected using a questionnaire form. Blood samples of ~ 10 μL were collected by venipuncture for the diagnosis of malaria using FM and light microscopy (LM). Performances of FM with respect to sensitivity (Se), specificity (Sp), positive and negative predictive values (PPV and NPV), positive and negative likelihood rates (PLR and NLR), accuracy, reliability, and Kappa index were calculated using LM as gold standard. Results In total, 442 employees, aged 37.8 ± 9.7 years old on average, were included in the study. Prevalence of malaria using FM and LM was 39.2% and 17%, respectively (p < 0.01). Plasmodium falciparum and P. vivax were the two species involved in malaria infection cases. In terms of developmental stages, 68%, 45.3%, and 1.3% of employees carried gametocytes, trophozoites, and schizonts, respectively. Findings on diagnostic performances of FM were as follows: Se = 84%, Sp = 69.95%, PPV = 63.58%, NPV = 95.5%, accuracy = 89.36%, and reliability = 53.95%. Sensitivity of Cyscope® microscope increased as a function of parasitemia with values ranging from 76.92% at parasitemia between 1 and 500 parasites/μL to 91.11% at parasitemia between 501 and 5000 parasites/μL. The geometric mean parasite density was1850 parasites per μL of blood (range 1600-40,000), and most of employees (60.8%) had moderate parasitemia. The performances of FM were similar between febrile and afebrile patients. Conclusions This study showed good performances of Cyscope® microscope and outlines that this diagnostic tool could be used in management of malaria at workplace.
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Affiliation(s)
- Christian Mbohou Nchetnkou
- Department of Animal Organisms, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Hervé Nyabeyeu Nyabeyeu
- Department of Animal Organisms, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Loick P Kojom Foko
- Department of Animal Organisms, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Leopold G Lehman
- Department of Animal Organisms, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon.,Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, P.O. Box 24157, Douala, Cameroon
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6
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Pigeault R, Isaïa J, Yerbanga RS, Dabiré KR, Ouédraogo JB, Cohuet A, Lefèvre T, Christe P. Different distribution of malaria parasite in left and right extremities of vertebrate hosts translates into differences in parasite transmission. Sci Rep 2020; 10:10183. [PMID: 32576924 PMCID: PMC7311528 DOI: 10.1038/s41598-020-67180-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 06/04/2020] [Indexed: 11/16/2022] Open
Abstract
Malaria, a vector-borne disease caused by Plasmodium spp., remains a major global cause of mortality. Optimization of disease control strategies requires a thorough understanding of the processes underlying parasite transmission. While the number of transmissible stages (gametocytes) of Plasmodium in blood is frequently used as an indicator of host-to-mosquito transmission potential, this relationship is not always clear. Significant effort has been made in developing molecular tools that improve gametocyte density estimation and therefore prediction of mosquito infection rates. However a significant level of uncertainty around estimates remains. The weakness in the relationship between gametocyte burden, measured from a blood sample, and the mosquito infection rate could be explained by a non-homogeneous distribution of gametocytes in the bloodstream. The estimated gametocyte density would then only be a single snapshot that does not reflect the host infectivity. This aspect of Plasmodium infection, however, remains largely neglected. In both humans and birds, we found here that the gametocyte densities differed depending on which side of the body the sample was taken, suggesting that gametocytes are not homogeneously distributed within the vertebrate host. We observed a fluctuating asymmetry, in other words, the extremity of the body with the highest density of parasites is not always the same from one individual to another. An estimation of gametocyte density from only one blood sample, as is commonly measured, could, therefore, over- or underestimated the infectivity of gametocyte carriers. This might have important consequences on the epidemiology of the disease since we show that this variation influences host-to-mosquito transmission. Vectors fed on the least infected body part had a lower parasite burden than those fed on the most infected part. The heterogeneous distribution of gametocytes in bloodstream should be considered to improve diagnosis and test new malaria control strategies.
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Affiliation(s)
- Romain Pigeault
- Department of Ecology and Evolution, CH-1015, Lausanne, Switzerland.
| | - Julie Isaïa
- Department of Ecology and Evolution, CH-1015, Lausanne, Switzerland
| | | | - Kounbobr R Dabiré
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | | | - Anna Cohuet
- Unité MIVEGEC, IRD 224-CNRS 5290-Université Montpellier, Montpellier, France
| | - Thierry Lefèvre
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
- Unité MIVEGEC, IRD 224-CNRS 5290-Université Montpellier, Montpellier, France
| | - Philippe Christe
- Department of Ecology and Evolution, CH-1015, Lausanne, Switzerland
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7
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Talman AM, Ouologuem DTD, Love K, Howick VM, Mulamba C, Haidara A, Dara N, Sylla D, Sacko A, Coulibaly MM, Dao F, Sangare CPO, Djimde A, Lawniczak MKN. Uptake of Plasmodium falciparum Gametocytes During Mosquito Bloodmeal by Direct and Membrane Feeding. Front Microbiol 2020; 11:246. [PMID: 32194521 PMCID: PMC7062676 DOI: 10.3389/fmicb.2020.00246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/03/2020] [Indexed: 11/25/2022] Open
Abstract
Plasmodium falciparum remains one of the leading causes of child mortality, and nearly half of the world's population is at risk of contracting malaria. While pathogenesis results from replication of asexual forms in human red blood cells, it is the sexually differentiated forms, gametocytes, which are responsible for the spread of the disease. For transmission to succeed, both mature male and female gametocytes must be taken up by a female Anopheles mosquito during its blood meal for subsequent differentiation into gametes and mating inside the mosquito gut. Observed circulating numbers of gametocytes in the human host are often surprisingly low. A pre-fertilization behavior, such as skin sequestration, has been hypothesized to explain the efficiency of human-to-mosquito transmission but has not been sufficiently tested due to a lack of appropriate tools. In this study, we describe the optimization of a qPCR tool that enables the relative quantification of gametocytes within very small input samples. Such a tool allows for the quantification of gametocytes in different compartments of the host and the vector that could potentially unravel mechanisms that enable highly efficient malaria transmission. We demonstrate the use of our gametocyte quantification method in mosquito blood meals from both direct skin feeding on Plasmodium gametocyte carriers and standard membrane feeding assay. Relative gametocyte abundance was not different between mosquitoes fed through a membrane or directly on the skin suggesting that there is no systematic enrichment of gametocytes picked up in the skin.
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Affiliation(s)
- Arthur M. Talman
- Wellcome Sanger Institute, Hinxton, United Kingdom
- MIVEGEC, IRD, CNRS, University of Montpellier, Montpellier, France
| | - Dinkorma T. D. Ouologuem
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Katie Love
- Wellcome Sanger Institute, Hinxton, United Kingdom
| | | | | | - Aboubecrin Haidara
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Niawanlou Dara
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Daman Sylla
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Adama Sacko
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Mamadou M. Coulibaly
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Francois Dao
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Cheick P. O. Sangare
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Abdoulaye Djimde
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
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8
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de Jong RM, Tebeje SK, Meerstein‐Kessel L, Tadesse FG, Jore MM, Stone W, Bousema T. Immunity against sexual stage Plasmodium falciparum and Plasmodium vivax parasites. Immunol Rev 2020; 293:190-215. [PMID: 31840844 PMCID: PMC6973022 DOI: 10.1111/imr.12828] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/30/2019] [Accepted: 11/14/2019] [Indexed: 12/25/2022]
Abstract
The efficient spread of malaria from infected humans to mosquitoes is a major challenge for malaria elimination initiatives. Gametocytes are the only Plasmodium life stage infectious to mosquitoes. Here, we summarize evidence for naturally acquired anti-gametocyte immunity and the current state of transmission blocking vaccines (TBV). Although gametocytes are intra-erythrocytic when present in infected humans, developing Plasmodium falciparum gametocytes may express proteins on the surface of red blood cells that elicit immune responses in naturally exposed individuals. This immune response may reduce the burden of circulating gametocytes. For both P. falciparum and Plasmodium vivax, there is a solid evidence that antibodies against antigens present on the gametocyte surface, when co-ingested with gametocytes, can influence transmission to mosquitoes. Transmission reducing immunity, reducing the burden of infection in mosquitoes, is a well-acknowledged but poorly quantified phenomenon that forms the basis for the development of TBV. Transmission enhancing immunity, increasing the likelihood or intensity of transmission to mosquitoes, is more speculative in nature but is convincingly demonstrated for P. vivax. With the increased interest in malaria elimination, TBV and monoclonal antibodies have moved to the center stage of malaria vaccine development. Methodologies to prioritize and evaluate products are urgently needed.
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MESH Headings
- Antibodies, Blocking/immunology
- Antibodies, Protozoan/immunology
- Host-Parasite Interactions/immunology
- Humans
- Immunity
- Immunomodulation
- Life Cycle Stages
- Malaria Vaccines/immunology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/transmission
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Malaria, Vivax/transmission
- Plasmodium falciparum/growth & development
- Plasmodium falciparum/immunology
- Plasmodium vivax/growth & development
- Plasmodium vivax/immunology
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Affiliation(s)
- Roos M. de Jong
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | | | - Lisette Meerstein‐Kessel
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Centre for Molecular and Biomolecular InformaticsRadboud Institute for Molecular Life SciencesNijmegenThe Netherlands
| | - Fitsum G. Tadesse
- Armauer Hansen Research InstituteAddis AbabaEthiopia
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Matthijs M. Jore
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Will Stone
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
| | - Teun Bousema
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
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9
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Meibalan E, Barry A, Gibbins MP, Awandu S, Meerstein-Kessel L, Achcar F, Bopp S, Moxon C, Diarra A, Debe S, Ouédraogo N, Barry-Some I, Badoum ES, Fagnima T, Lanke K, Gonçalves BP, Bradley J, Wirth D, Drakeley C, Guelbeogo WM, Tiono AB, Marti M, Bousema T. Plasmodium falciparum Gametocyte Density and Infectivity in Peripheral Blood and Skin Tissue of Naturally Infected Parasite Carriers in Burkina Faso. J Infect Dis 2019; 223:1822-1830. [PMID: 31875909 PMCID: PMC8161640 DOI: 10.1093/infdis/jiz680] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 12/23/2019] [Indexed: 12/22/2022] Open
Abstract
Background Plasmodium falciparum transmission depends on mature gametocytes that can be ingested by mosquitoes taking a blood meal on human skin. Although gametocyte skin sequestration has long been hypothesized as important contributor to efficient malaria transmission, this has never been formally tested. Methods In naturally infected gametocyte carriers from Burkina Faso, we assessed infectivity to mosquitoes by direct skin feeding and membrane feeding. We directly quantified male and female gametocytes and asexual parasites in finger-prick and venous blood samples, skin biopsy samples, and in of mosquitoes that fed on venous blood or directly on skin. Gametocytes were visualized in skin tissue with confocal microscopy. Results Although more mosquitoes became infected when feeding directly on skin then when feeding on venous blood (odds ratio, 2.01; 95% confidence interval, 1.21–3.33; P = .007), concentrations of gametocytes were not higher in the subdermal skin vasculature than in other blood compartments; only sparse gametocytes were observed in skin tissue. Discussion Our data strongly suggest that there is no significant skin sequestration of P. falciparum gametocytes. Gametocyte densities in peripheral blood are thus informative for predicting onward transmission potential to mosquitoes and can be used to target and monitor malaria elimination initiatives.
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Affiliation(s)
- Elamaran Meibalan
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Aissata Barry
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso.,Radboud Institute for Health Sciences, Radboud University Medical Center, the Netherlands
| | - Matthew P Gibbins
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Shehu Awandu
- Radboud Institute for Health Sciences, Radboud University Medical Center, the Netherlands
| | | | - Fiona Achcar
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Selina Bopp
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Christopher Moxon
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Amidou Diarra
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Siaka Debe
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Nicolas Ouédraogo
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Ines Barry-Some
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Emilie S Badoum
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Traoré Fagnima
- Centre Hospitalier Universitaire Régional de Ouahigoua, Université de Ouahigouya, Burkina Faso
| | - Kjerstin Lanke
- Radboud Institute for Health Sciences, Radboud University Medical Center, the Netherlands
| | - Bronner P Gonçalves
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Dyann Wirth
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Chris Drakeley
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Alfred B Tiono
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Matthias Marti
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, the Netherlands.,Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
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10
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Antonio-Nkondjio C, Ndo C, Njiokou F, Bigoga JD, Awono-Ambene P, Etang J, Ekobo AS, Wondji CS. Review of malaria situation in Cameroon: technical viewpoint on challenges and prospects for disease elimination. Parasit Vectors 2019; 12:501. [PMID: 31655608 PMCID: PMC6815446 DOI: 10.1186/s13071-019-3753-8] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 10/18/2019] [Indexed: 11/30/2022] Open
Abstract
Malaria still has a devastating impact on public health and welfare in Cameroon. Despite the increasing number of studies conducted on disease prevalence, transmission patterns or treatment, there are to date, not enough studies summarising findings from previous works in order to identify gaps in knowledge and areas of interest where further evidence is needed to drive malaria elimination efforts. The present study seeks to address these gaps by providing a review of studies conducted so far on malaria in Cameroon since the 1940s to date. Over 250 scientific publications were consulted for this purpose. Although there has been increased scale-up of vector control interventions which significantly reduced the morbidity and mortality to malaria across the country from a prevalence of 41% of the population reporting at least one malaria case episode in 2000 to a prevalence of 24% in 2017, the situation is not yet under control. There is a high variability in disease endemicity between epidemiological settings with prevalence of Plasmodium parasitaemia varying from 7 to 85% in children aged 6 months to 15 years after long-lasting insecticidal nets (LLINs) scale-up. Four species of Plasmodium have been recorded across the country: Plasmodium falciparum, P. malariae, P. ovale and P. vivax. Several primate-infecting Plasmodium spp. are also circulating in Cameroon. A decline of artemisinin-based combinations therapeutic efficacy from 97% in 2006 to 90% in 2016 have been reported. Several mutations in the P. falciparum chloroquine resistance (Pfcrt) and P. falciparum multidrug resistance 1 (Pfmdr1) genes conferring resistance to either 4-amino-quinoleine, mefloquine, halofanthrine and quinine have been documented. Mutations in the Pfdhfr and Pfdhps genes involved in sulfadoxine-pyrimethamine are also on the rise. No mutation associated with artemisinin resistance has been recorded. Sixteen anopheline species contribute to malaria parasite transmission with six recognized as major vectors: An. gambiae, An. coluzzii, An. arabiensis, An. funestus, An. nili and An. moucheti. Studies conducted so far, indicated rapid expansion of DDT, pyrethroid and carbamate resistance in An. gambiae, An. coluzzii, An. arabiensis and An. funestus threatening the performance of LLINs. This review highlights the complex situation of malaria in Cameroon and the need to urgently implement and reinforce integrated control strategies in different epidemiological settings, as part of the substantial efforts to consolidate gains and advance towards malaria elimination in the country.
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Affiliation(s)
- Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288 Yaoundé, Cameroun
- Centre for Research in Infectious Disease (CRID), P.O. Box 13591, Yaoundé, Cameroon
- Vector Biology Liverpool School of Tropical medicine Pembroke Place, Liverpool, UK
| | - Cyrille Ndo
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 24157, Douala, Cameroon
- Centre for Research in Infectious Disease (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Flobert Njiokou
- Centre for Research in Infectious Disease (CRID), P.O. Box 13591, Yaoundé, Cameroon
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Jude D. Bigoga
- Laboratory for Vector Biology and control, National Reference Unit for Vector Control, The Biotechnology Center, Nkolbisson-University of Yaounde I, P.O. Box 3851, Messa, Yaounde, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaounde, Cameroon
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288 Yaoundé, Cameroun
| | - Josiane Etang
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288 Yaoundé, Cameroun
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 24157, Douala, Cameroon
- Institute for Insect Biotechnology, Justus Liebig University Gießen, Winchester Str. 2, 35394 Gießen, Germany
| | - Albert Same Ekobo
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Charles S. Wondji
- Centre for Research in Infectious Disease (CRID), P.O. Box 13591, Yaoundé, Cameroon
- Vector Biology Liverpool School of Tropical medicine Pembroke Place, Liverpool, UK
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11
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Mischlinger J, Pitzinger P, Veletzky L, Groger M, Zoleko-Manego R, Adegnika AA, Agnandji ST, Lell B, Kremsner PG, Tannich E, Mombo-Ngoma G, Mordmüller B, Ramharter M. Use of Capillary Blood Samples Leads to Higher Parasitemia Estimates and Higher Diagnostic Sensitivity of Microscopic and Molecular Diagnostics of Malaria Than Venous Blood Samples. J Infect Dis 2019; 218:1296-1305. [PMID: 29800345 DOI: 10.1093/infdis/jiy319] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 05/23/2018] [Indexed: 11/14/2022] Open
Abstract
Background Diagnosis of malaria is usually based on samples of peripheral blood. However, it is unclear whether capillary (CAP) or venous (VEN) blood samples provide better diagnostic performance. Quantitative differences of parasitemia between CAP and VEN blood and diagnostic performance characteristics were investigated. Methods Patients were recruited between September 2015 and February 2016 in Gabon. Light microscopy and quantitative polymerase chain reaction (qPCR) measured parasitemia of paired CAP and VEN samples. CAP and VEN performance characteristics using microscopy were evaluated against a qPCR gold standard. Results Microscopy revealed a median parasitemia of 495/μL in CAP and 429/μL in VEN samples, manifesting in a 16.6% (P = .04) higher CAP parasitemia compared with VEN parasitemia. Concordantly, in qPCR -0.278 (P = .006) cycles were required for signal detection in CAP samples. CAP sensitivity of microscopy relative to the gold standard was 81.5% vs VEN sensitivity of 73.4%, while specificities were 91%. CAP and VEN sensitivities dropped to 63.3% and 45.9%, respectively, for a subpopulation of low-level parasitemias, whereas specificities were 92%. Conclusions CAP sampling leads to higher parasitemias compared to VEN sampling and improves diagnostic sensitivity. These findings may have important implications for routine diagnostics, research, and elimination campaigns of malaria.
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Affiliation(s)
- Johannes Mischlinger
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Austria.,Centre de Recherches Médicales de Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Germany.,German Center for Infection Research, partner site Tübingen, Germany.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, Germany.,I Department of Medicine University Medical Center Hamburg-Eppendorf, Germany
| | - Paul Pitzinger
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Austria.,Centre de Recherches Médicales de Lambaréné, Gabon
| | - Luzia Veletzky
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Austria.,Centre de Recherches Médicales de Lambaréné, Gabon.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, Germany.,I Department of Medicine University Medical Center Hamburg-Eppendorf, Germany
| | - Mirjam Groger
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Austria.,Centre de Recherches Médicales de Lambaréné, Gabon.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, Germany.,I Department of Medicine University Medical Center Hamburg-Eppendorf, Germany
| | - Rella Zoleko-Manego
- Centre de Recherches Médicales de Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Germany.,German Center for Infection Research, partner site Tübingen, Germany.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, Germany.,I Department of Medicine University Medical Center Hamburg-Eppendorf, Germany
| | - Ayola A Adegnika
- Centre de Recherches Médicales de Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Germany.,German Center for Infection Research, partner site Tübingen, Germany
| | - Selidji T Agnandji
- Centre de Recherches Médicales de Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Germany.,German Center for Infection Research, partner site Tübingen, Germany
| | - Bertrand Lell
- Centre de Recherches Médicales de Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Germany.,German Center for Infection Research, partner site Tübingen, Germany
| | - Peter G Kremsner
- Centre de Recherches Médicales de Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Germany.,German Center for Infection Research, partner site Tübingen, Germany
| | - Egbert Tannich
- Bernhard Nocht Institute for Tropical Medicine, World Health Organization Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Germany.,German Centre for Infection Research, partner site Hamburg-Luebeck-Borstel, Hamburg, Germany
| | - Ghyslain Mombo-Ngoma
- Centre de Recherches Médicales de Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Germany.,German Center for Infection Research, partner site Tübingen, Germany.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, Germany.,I Department of Medicine University Medical Center Hamburg-Eppendorf, Germany.,Université des Sciences de la Santé Gabon, Département de Parasitology, Malaria Clinical and Operational Research Unit, Melen Hospital, Libreville, Gabon
| | - Benjamin Mordmüller
- Centre de Recherches Médicales de Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, Germany.,German Center for Infection Research, partner site Tübingen, Germany
| | - Michael Ramharter
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine, Germany.,I Department of Medicine University Medical Center Hamburg-Eppendorf, Germany.,German Centre for Infection Research, partner site Hamburg-Luebeck-Borstel, Hamburg, Germany
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12
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Lehane A, Were M, Wade M, Hamadu M, Cahill M, Kiconco S, Kajubi R, Aweeka F, Mwebaza N, Li F, Parikh S. Comparison on simultaneous caillary and venous parasite density and genotyping results from children and adults with uncomplicated malaria: a prospective observational study in Uganda. BMC Infect Dis 2019; 19:559. [PMID: 31242863 PMCID: PMC6595677 DOI: 10.1186/s12879-019-4174-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 06/09/2019] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Blood smear microscopy remains the gold-standard method to diagnose and quantify malaria parasite density. In addition, parasite genotyping of select loci is the most utilized method for distinguishing recrudescent and new infections and to determine the number of strains per sample. In research settings, blood may be obtained from capillary or venous compartments, and results from these matrices have been used interchangeably. Our aim was to compare quantitative results for parasite density and strain complexity from both compartments. METHODS In a prospective observational study, children and adults presenting with uncomplicated Plasmodium falciparum malaria, simultaneous capillary and venous blood smears and dried blood spots were collected over 42-days following treatment with artemether-lumefantrine. Blood smears were read by two microscopists, any discrepancies resolved by a third reader. Parasite DNA fingerprinting was conducted using six microsatellites. Bland Altman analysis and paired t-test/McNemar's test were used to assess the difference in density readings and measurements. RESULTS Two hundred twenty-three participants were included in the analysis (177 children (35 HIV-infected/142 HIV-uninfected), 21 HIV-uninfected pregnant women, and 25 HIV-uninfected non-pregnant adults). Parasite density measurements did not statistically differ between capillary and venous blood smears at the time of presentation, nor over the course of 42-day follow-up. Characterization of merozoite surface protein-2 (MSP-2) genetic polymorphism demonstrated a higher level of strain diversity at the time of presentation in venous samples, as compared with capillary specimens (p = 0.02). There was a high degree of variability in genotype-corrected outcomes when pairs of samples from each compartment were compared using MSP-2 alone, although the variability was reduced with the use of multiple markers. CONCLUSIONS Parasite density measurements do not statistically differ between capillary and venous compartments in all studied demographic groups at the time of presentation with malaria, or over the course of follow-up. More strains were detected by MSP-2 genotyping in venous samples than in capillary samples at the time of malaria diagnosis. The use of multiple polymorphic markers reduces the impact of variability in strain detection on genotype-corrected outcomes. This study confirms that both capillary and venous compartments can be used for sampling with confidence in the clinical research setting. TRIAL REGISTRATION The trial was registered at ClinicalTrials.gov under registration no. NCT01717885 .
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Affiliation(s)
- Aine Lehane
- Yale School of Public Health, New Haven, CT USA
| | - Moses Were
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | | | - Sylvia Kiconco
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Richard Kajubi
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Norah Mwebaza
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Fangyong Li
- Yale School of Public Health, New Haven, CT USA
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13
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Essangui E, Eboumbou Moukoko CE, Nguedia N, Tchokwansi M, Banlanjo U, Maloba F, Fogang B, Donkeu C, Biabi M, Cheteug G, Kemleu S, Elanga-Ndille E, Lehman L, Ayong L. Demographical, hematological and serological risk factors for Plasmodium falciparum gametocyte carriage in a high stable transmission zone in Cameroon. PLoS One 2019; 14:e0216133. [PMID: 31022294 PMCID: PMC6483257 DOI: 10.1371/journal.pone.0216133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/15/2019] [Indexed: 01/22/2023] Open
Abstract
Presence of mature gametocyte forms of malaria parasites in peripheral blood is a key requirement for malaria transmission. Yet, studies conducted in most malaria transmission zones report the absence of gametocyte in the majority of patients. We therefore sought to determine the risk factors of both all-stage and mature gametocyte carriage in an area with high stable transmission of Plasmodium falciparum in Cameroon. Gametocyte positivity was determined using three complementary methods: thick blood smear microscopy, RT-PCR and RT-LAMP, whereas exposure to the infection was assessed by enzyme-linked immunosorbent assay. Of 361 malaria endemic residents randomly included in the study (mean age: 28±23 years, age range: 2–100 years, male/female sex ratio: 1.1), 87.8% were diagnosed with P. falciparum infection, of whom 45.7% presented with fever (axillary body temperature ≥37.5°C). Mature gametocyte positivity was 1.9% by thick blood smear microscopy and 8.9% by RT-PCR targeting the mature gametocyte transcript, Pfs25. The gametocyte positivity rate was 24.1% and 36.3% by RT-PCR or RT-LAMP, respectively, when targeting the sexual stage marker, Pfs16. Multivariate analyses revealed anemia as a common independent risk factor for both mature and all-stage gametocyte carriage, whereas fever and low anti-gametocyte antibody levels were independently associated with all-stage gametocyte carriage only. Taken together, the data suggest important differences in risk factors of gametocyte carriage depending on stage analyzed, with anemia, fever and low antiplasmodial plasma antibody levels representing the major contributing risk factors.
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Affiliation(s)
- Estelle Essangui
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Niels Nguedia
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | | | - Umaru Banlanjo
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | - Franklin Maloba
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Marie Biabi
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Glwadys Cheteug
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Sylvie Kemleu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Emmanuel Elanga-Ndille
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Centre for Research in Infectious Diseases, Yaounde, Cameroon
| | - Léopold Lehman
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- * E-mail:
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14
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Kiemde F, Tahita MC, Bonko MDA, Mens PF, Tinto H, van Hensbroek MB, Schallig HDFH. Implementation of a malaria rapid diagnostic test in a rural setting of Nanoro, Burkina Faso: from expectation to reality. Malar J 2018; 17:316. [PMID: 30165849 PMCID: PMC6117982 DOI: 10.1186/s12936-018-2468-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/27/2018] [Indexed: 01/16/2023] Open
Abstract
Background Malaria rapid diagnostic tests (RDTs) are nowadays widely used in malaria endemic countries as an alternative to microscopy for the diagnosis of malaria. However, quality control of test performance and execution in the field are important in order to ensure proper use and adequate diagnosis of malaria. The current study compared the performance of a histidine-rich protein 2-based RDT used at peripheral health facilities level in real life conditions with that performed at central reference laboratory level with strict adherence to manufacturer instructions. Methods Febrile children attending rural health clinics were tested for malaria with a RDT provided by the Ministry of Health of Burkina Faso as recommended by the National Malaria Control Programme. In addition, a blood sample was collected in an EDTA tube from all study cases for retesting with the same brand of RDT following the manufacturer’s instructions with expert malaria microscopy as gold standard at the central reference laboratory. Fisher exact test was used to compare the proportions by estimating the p-value (p ≤ 0.05) as statistically significant. Results In total, 407 febrile children were included in the study and malaria was diagnosed in 59.9% (244/407) of the cases with expert malaria microscopy. The sensitivity of malaria RDT testing performed at health facilities was 97.5% and comparable to that achieved at the laboratory (98.8%). The number of malaria false negatives was not statistically significant between the two groups (p = 0.5209). However, the malaria RDT testing performed at health facilities had a specificity issue (52.8%) and was much lower compared to RDT testing performed at laboratory (74.2%). The number of malaria false positives was statistically significantly different between the two groups (p = 0.0005). Conclusion Malaria RDT testing performed at the participating rural health facilities resulted in more malaria false positives compared to those performed at central laboratory. Several factors, including storage and transportation conditions but also training of health workers, are most likely to influence test performance. Therefore, it is very important to have appropriate quality control and training programmes in place to ensure correct performance of RDT testing.
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Affiliation(s)
- Francois Kiemde
- Institut de Recherche en Science de la Sante-Unité de Recherche Clinique de Nanoro, Nanoro, Burkina Faso. .,Parasitology Unit, Department of Medical Microbiology, Academic Medical Centre, Amsterdam, The Netherlands. .,Global Child Health Group, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
| | - Marc Christian Tahita
- Institut de Recherche en Science de la Sante-Unité de Recherche Clinique de Nanoro, Nanoro, Burkina Faso
| | - Massa Dit Achille Bonko
- Institut de Recherche en Science de la Sante-Unité de Recherche Clinique de Nanoro, Nanoro, Burkina Faso.,Parasitology Unit, Department of Medical Microbiology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Petra F Mens
- Parasitology Unit, Department of Medical Microbiology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Halidou Tinto
- Institut de Recherche en Science de la Sante-Unité de Recherche Clinique de Nanoro, Nanoro, Burkina Faso
| | | | - Henk D F H Schallig
- Parasitology Unit, Department of Medical Microbiology, Academic Medical Centre, Amsterdam, The Netherlands
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15
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Operational Performance of a Plasmodium falciparum Ultrasensitive Rapid Diagnostic Test for Detection of Asymptomatic Infections in Eastern Myanmar. J Clin Microbiol 2018; 56:JCM.00565-18. [PMID: 29898998 PMCID: PMC6062819 DOI: 10.1128/jcm.00565-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/05/2018] [Indexed: 11/21/2022] Open
Abstract
In the Greater Mekong Subregion in Southeast Asia, malaria elimination strategies need to target all Plasmodium falciparum parasites, including those carried asymptomatically. More than 70% of asymptomatic carriers are not detected by current rapid diagnostic tests (RDTs) or microscopy. In the Greater Mekong Subregion in Southeast Asia, malaria elimination strategies need to target all Plasmodium falciparum parasites, including those carried asymptomatically. More than 70% of asymptomatic carriers are not detected by current rapid diagnostic tests (RDTs) or microscopy. An HRP2-based ultrasensitive RDT (uRDT) developed to improve the detection of low-density infections was evaluated during prevalence surveys within a malaria elimination program in a low-transmission area of eastern Myanmar. Surveys were conducted to identify high-prevalence villages. Two-milliliter venous blood samples were collected from asymptomatic adult volunteers and transported to the laboratory. Plasmodium parasites were detected by RDT, uRDT, microscopy, ultrasensitive qPCR (uPCR), and multiplex enzyme-linked immunosorbent assay (ELISA). The sensitivity, specificity, and predictive positive and negative values of RDT and uRDT were calculated compared to uPCR and ELISA. Parasite and antigen concentrations detected by each test were defined using uPCR and ELISA, respectively. A total of 1,509 samples, including 208 P. falciparum-positive samples were analyzed with all tests. The sensitivity of the uRDT was twofold higher than that of RDT, 51.4% versus 25.2%, with minor specificity loss, 99.5% versus 99.9%, against the combined reference (uPCR plus ELISA). The geometric mean parasitemia detected by uRDT in P. falciparum monospecific infections was 3,019 parasites per ml (95% confidence interval [95% CI], 1,790 to 5,094; n = 79) compared to 11,352 parasites per ml (95% CI, 5,643 to 22,837; n = 38) by RDT. The sensitivities of uRDT and RDT dropped to 34.6% and 15.1%, respectively, for the matched tests performed in the field. The uRDT performed consistently better than RDT and microscopy at low parasitemias. It shows promising characteristics for the identification of high-prevalence communities and warrants further evaluation in mass screening and treatment interventions.
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16
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Bradley J, Stone W, Da DF, Morlais I, Dicko A, Cohuet A, Guelbeogo WM, Mahamar A, Nsango S, Soumaré HM, Diawara H, Lanke K, Graumans W, Siebelink-Stoter R, van de Vegte-Bolmer M, Chen I, Tiono A, Gonçalves BP, Gosling R, Sauerwein RW, Drakeley C, Churcher TS, Bousema T. Predicting the likelihood and intensity of mosquito infection from sex specific Plasmodium falciparum gametocyte density. eLife 2018; 7:34463. [PMID: 29848446 PMCID: PMC6013255 DOI: 10.7554/elife.34463] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/26/2018] [Indexed: 12/02/2022] Open
Abstract
Understanding the importance of gametocyte density on human-to-mosquito transmission is of immediate relevance to malaria control. Previous work (Churcher et al., 2013) indicated a complex relationship between gametocyte density and mosquito infection. Here we use data from 148 feeding experiments on naturally infected gametocyte carriers to show that the relationship is much simpler and depends on both female and male parasite density. The proportion of mosquitoes infected is primarily determined by the density of female gametocytes though transmission from low gametocyte densities may be impeded by a lack of male parasites. Improved precision of gametocyte quantification simplifies the shape of the relationship with infection increasing rapidly before plateauing at higher densities. The mean number of oocysts per mosquito rises quickly with gametocyte density but continues to increase across densities examined. The work highlights the importance of measuring both female and male gametocyte density when estimating the human reservoir of infection.
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Affiliation(s)
- John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Will Stone
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Dari F Da
- Institut de Recherche en Sciences de la Santé, Direction, Bobo Dioulasso, Burkina Faso
| | - Isabelle Morlais
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Anna Cohuet
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Wamdaogo M Guelbeogo
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Almahamoudou Mahamar
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Sandrine Nsango
- Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, Douala, Cameroon
| | - Harouna M Soumaré
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Halimatou Diawara
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Kjerstin Lanke
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Wouter Graumans
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Rianne Siebelink-Stoter
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Ingrid Chen
- Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, San Francisco, United States
| | - Alfred Tiono
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Bronner Pamplona Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Roland Gosling
- Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, San Francisco, United States
| | - Robert W Sauerwein
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Thomas S Churcher
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Koepfli C, Yan G. Plasmodium Gametocytes in Field Studies: Do We Measure Commitment to Transmission or Detectability? Trends Parasitol 2018; 34:378-387. [PMID: 29544966 DOI: 10.1016/j.pt.2018.02.009] [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: 01/12/2018] [Revised: 02/07/2018] [Accepted: 02/21/2018] [Indexed: 01/05/2023]
Abstract
The proportion of Plasmodium spp. infections carrying gametocytes, and gametocyte densities, are often reported as surrogate markers for transmission potential. It remains unclear whether parasites under natural conditions adjust commitment to transmission depending on external factors. Population-based surveys comprising mostly asymptomatic low-density infections are always impacted by the sensitivity of the assays used to diagnose infections and detect gametocytes. Asexual parasite density is an important predictor for the probability of detecting gametocytes, and in many cases it can explain patterns in gametocyte carriage without the need for an adjustment of the gametocyte conversion rate. When reporting gametocyte data, quantification of blood-stage parasitemia and its inclusion as a confounder in multivariable analyses is essential.
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Affiliation(s)
- Cristian Koepfli
- Program in Public Health, University of California, Irvine, CA, 92697, USA.
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, CA, 92697, USA
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