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Stone W, Sawa P, Lanke K, Rijpma S, Oriango R, Nyaurah M, Osodo P, Osoti V, Mahamar A, Diawara H, Woestenenk R, Graumans W, van de Vegte-Bolmer M, Bradley J, Chen I, Brown J, Siciliano G, Alano P, Gosling R, Dicko A, Drakeley C, Bousema T. A Molecular Assay to Quantify Male and Female Plasmodium falciparum Gametocytes: Results From 2 Randomized Controlled Trials Using Primaquine for Gametocyte Clearance. J Infect Dis 2017; 216:457-467. [PMID: 28931236 PMCID: PMC5853855 DOI: 10.1093/infdis/jix237] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Single low-dose primaquine (PQ) reduces Plasmodium falciparum infectivity before it impacts gametocyte density. Here, we examined the effect of PQ on gametocyte sex ratio as a possible explanation for this early sterilizing effect. Methods Quantitative reverse-transcription polymerase chain reaction assays were developed to quantify female gametocytes (targeting Pfs25 messenger RNA [mRNA]) and male gametocytes (targeting Pf3D7_1469900 mRNA) in 2 randomized trials in Kenya and Mali, comparing dihydroartemisinin-piperaquine (DP) alone to DP with PQ. Gametocyte sex ratio was examined in relation to time since treatment and infectivity to mosquitoes. Results In Kenya, the median proportion of male gametocytes was 0.33 at baseline. Seven days after treatment, gametocyte density was significantly reduced in the DP-PQ arm relative to the DP arm (females: 0.05% [interquartile range {IQR}, 0.0–0.7%] of baseline; males: 3.4% [IQR, 0.4%–32.9%] of baseline; P < .001). Twenty-four hours after treatment, gametocyte sex ratio became male-biased and was not significantly different between the DP and DP-PQ groups. In Mali, there was no significant difference in sex ratio between the DP and DP-PQ groups (>0.125 mg/kg) 48 hours after treatment, and gametocyte sex ratio was not associated with mosquito infection rates. Conclusions The early sterilizing effects of PQ may not be explained by the preferential clearance of male gametocytes and may be due to an effect on gametocyte fitness.
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Affiliation(s)
- Will Stone
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Patrick Sawa
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sanna Rijpma
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robin Oriango
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Maureen Nyaurah
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Paul Osodo
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Victor Osoti
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Almahamoudou Mahamar
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Mali
| | - Halimatou Diawara
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Mali
| | - Rob Woestenenk
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Wouter Graumans
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - John Bradley
- Medical Research Council Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Ingrid Chen
- Global Health Group, Malaria Elimination Initiative
| | - Joelle Brown
- Department of Epidemiology and Biostatistics, University of California, San Francisco
| | - Giulia Siciliano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Roly Gosling
- Global Health Group, Malaria Elimination Initiative.,Department of Epidemiology and Biostatistics, University of California, San Francisco
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Mali
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, United Kingdom
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Stevenson JC, Stresman GH, Baidjoe A, Okoth A, Oriango R, Owaga C, Marube E, Bousema T, Cox J, Drakeley C. Use of different transmission metrics to describe malaria epidemiology in the highlands of western Kenya. Malar J 2015; 14:418. [PMID: 26502920 PMCID: PMC4624380 DOI: 10.1186/s12936-015-0944-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 10/13/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Monitoring and evaluation of malaria programmes may require a combination of approaches to detect any effects of control. This is particularly true at lower transmission levels where detecting both infection and exposure to infection will provide additional evidence of any change. This paper describes use of three transmission metrics to explore the malaria epidemiology in the highlands of western Kenya. METHODS A malariometric survey was conducted in June 2009 in two highland districts, Kisii and Rachuonyo South, Nyanza Province, Kenya using a cluster design. Enumeration areas were used to sample 46 clusters from which 12 compounds were randomly sampled. Individuals provided a finger-blood sample to assess malaria infection (rapid diagnostic test, PCR) and exposure (anti-Plasmodium falciparum MSP-1 antibodies) and a questionnaire was administered to record household factors and assess use of vector control interventions. RESULTS Malaria prevalence infection rates were 3.0 % (95 % CI 2.2-4.2 %) by rapid diagnostic test (RDT) and 8.5 % (95 % CI 7.0-10.4 %) by PCR and these ranged from 0-13.1 to 0-14.8 % between clusters for RDT and PCR, respectively. Seroprevalence was 36.8 % (95 % CI 33.9-39.8) ranging from 18.6 to 65.8 %. Both RDT and PCR prevalences were highest in children aged 5-10 years but the proportion of infections that were sub-patent was highest in those between 15 and 20 years of age (78.1 %, 95 % CI 63.0-93.3 %) and those greater than 20 years (73.3 %, 95 % CI 64.5-81.9 %). Those reporting both indoor residual spraying (IRS) in their home and use of bed nets had lower exposure to malaria compared to those who reported using IRS or bed nets alone. CONCLUSIONS In this highland site in western Kenya malaria transmission was low, but highly heterogeneous. To accurately characterize the true extent of malaria transmission, more sensitive and complementary metrics such as PCR or serology are required in addition to the standard microscopy and/or RDTs that are routinely used. This is likely to be the case in other low endemicity settings.
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Affiliation(s)
- Jennifer C Stevenson
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. .,Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe St, Baltimore, MD, 21205, USA.
| | - Gillian H Stresman
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Amrish Baidjoe
- Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
| | - Albert Okoth
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya.
| | - Robin Oriango
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya.
| | - Chrispin Owaga
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya.
| | - Elizabeth Marube
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya.
| | - Teun Bousema
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. .,Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
| | - Jonathan Cox
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Chris Drakeley
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
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Stevenson JC, Stresman GH, Gitonga CW, Gillig J, Owaga C, Marube E, Odongo W, Okoth A, China P, Oriango R, Brooker SJ, Bousema T, Drakeley C, Cox J. Reliability of school surveys in estimating geographic variation in malaria transmission in the western Kenyan highlands. PLoS One 2013; 8:e77641. [PMID: 24143250 PMCID: PMC3797060 DOI: 10.1371/journal.pone.0077641] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/12/2013] [Indexed: 11/25/2022] Open
Abstract
Background School surveys provide an operational approach to assess malaria transmission through parasite prevalence. There is limited evidence on the comparability of prevalence estimates obtained from school and community surveys carried out at the same locality. Methods Concurrent school and community cross-sectional surveys were conducted in 46 school/community clusters in the western Kenyan highlands and households of school children were geolocated. Malaria was assessed by rapid diagnostic test (RDT) and combined seroprevalence of antibodies to bloodstage Plasmodium falciparum antigens. Results RDT prevalence in school and community populations was 25.7% (95% CI: 24.4-26.8) and 15.5% (95% CI: 14.4-16.7), respectively. Seroprevalence in the school and community populations was 51.9% (95% CI: 50.5-53.3) and 51.5% (95% CI: 49.5-52.9), respectively. RDT prevalence in schools could differentiate between low (<7%, 95% CI: 0-19%) and high (>39%, 95% CI: 25-49%) transmission areas in the community and, after a simple adjustment, were concordant with the community estimates. Conclusions Estimates of malaria prevalence from school surveys were consistently higher than those from community surveys and were strongly correlated. School-based estimates can be used as a reliable indicator of malaria transmission intensity in the wider community and may provide a basis for identifying priority areas for malaria control.
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Affiliation(s)
- Jennifer C. Stevenson
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Gillian H. Stresman
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Caroline W. Gitonga
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Malaria Public Health Department, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Jonathan Gillig
- Eck Institute for Global Health, University of Notre Dame, South Bend, Indiana, United States of America
| | - Chrispin Owaga
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Elizabeth Marube
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Wycliffe Odongo
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Albert Okoth
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Pauline China
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Robin Oriango
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Simon J. Brooker
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Malaria Public Health Department, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Teun Bousema
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jonathan Cox
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
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