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Kamau L, Bennett KL, Ochomo E, Herren J, Agumba S, Otieno S, Omoke D, Matoke-Muhia D, Mburu D, Mwangangi J, Ramaita E, Juma EO, Mbogo C, Barasa S, Miles A. The Anopheles coluzzii range extends into Kenya: detection, insecticide resistance profiles and population genetic structure in relation to conspecific populations in West and Central Africa. Malar J 2024; 23:122. [PMID: 38671462 PMCID: PMC11046809 DOI: 10.1186/s12936-024-04950-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Anopheles coluzzii is a primary vector of malaria found in West and Central Africa, but its presence has hitherto never been documented in Kenya. A thorough understanding of vector bionomics is important as it enables the implementation of targeted and effective vector control interventions. Malaria vector surveillance efforts in the country have tended to focus on historically known primary vectors. The current study sought to determine the taxonomic status of samples collected from five different malaria epidemiological zones in Kenya as well as describe the population genetic structure and insecticide resistance profiles in relation to other An. coluzzii populations. METHODS Mosquitoes were sampled as larvae from Busia, Kwale, Turkana, Kirinyaga and Kiambu counties, representing the range of malaria endemicities in Kenya, in 2019 and 2021 and emergent adults analysed using Whole Genome Sequencing (WGS) data processed in accordance with the Anopheles gambiae 1000 Genomes Project phase 3. Where available, historical samples from the same sites were included for WGS. Comparisons were made with An. coluzzii cohorts from West and Central Africa. RESULTS This study reports the detection of An. coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points from which samples were analyzed and its presence confirmed through taxonomic analysis. Additionally, there was a lack of strong population genetic differentiation between An. coluzzii from Kenya and those from the more northerly regions of West and Central Africa, suggesting they represent a connected extension to the known species range. Mutations associated with target-site resistance to DDT and pyrethroids and metabolic resistance to DDT were found at high frequencies up to 64%. The profile and frequencies of the variants observed were similar to An. coluzzii from West and Central Africa but the ace-1 mutation linked to organophosphate and carbamate resistance present in An. coluzzii from coastal West Africa was absent in Kenya. CONCLUSIONS These findings emphasize the need for the incorporation of genomics in comprehensive and routine vector surveillance to inform on the range of malaria vector species, and their insecticide resistance status to inform the choice of effective vector control approaches.
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Affiliation(s)
- Luna Kamau
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute, PO Box 54840, Nairobi, 00200, Kenya.
| | - Kelly L Bennett
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Eric Ochomo
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute, Nairobi, Kenya
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jeremy Herren
- International Center for Insect Physiology and Ecology (Icipe), Nairobi, Kenya
| | - Silas Agumba
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute, Nairobi, Kenya
| | - Samson Otieno
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute, Nairobi, Kenya
| | - Diana Omoke
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute, Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute, PO Box 54840, Nairobi, 00200, Kenya
- Pan African Mosquito Control Association (PAMCA), Nairobi, Kenya
| | - David Mburu
- Pwani University Biosciences Research Centre (PUBReC), Kilifi, Kenya
| | - Joseph Mwangangi
- Centre for Geographic Medicine Research-Coast (CGMR-C), Kenya Medical Research Institute, Nairobi, Kenya
| | - Edith Ramaita
- Ministry of Health-National Malaria Control Programme (NMCP), Kenya, Nairobi, Kenya
| | - Elijah O Juma
- Pan African Mosquito Control Association (PAMCA), Nairobi, Kenya
| | - Charles Mbogo
- Pan African Mosquito Control Association (PAMCA), Nairobi, Kenya
| | - Sonia Barasa
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
- Pan African Mosquito Control Association (PAMCA), Nairobi, Kenya
| | - Alistair Miles
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
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Kamau L, Bennett KL, Ochomo E, Herren J, Agumba S, Otieno S, Omoke D, Matoke-Muhia D, Mburu D, Mwangangi J, Ramaita E, Juma EO, Mbogo C, Barasa S, Miles A. The Anopheles coluzzii range extends into Kenya: Detection, insecticide resistance profiles and population genetic structure in relation to conspecific populations in West and Central Africa. Res Sq 2024:rs.3.rs-3953608. [PMID: 38410447 PMCID: PMC10896386 DOI: 10.21203/rs.3.rs-3953608/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Background Anopheles coluzzii is a primary vector of malaria found in West and Central Africa, but its presence has hitherto never been documented in Kenya. A thorough understanding of vector bionomics is important as it enables the implementation of targeted and effective vector control interventions. Malaria vector surveillance efforts in the country have tended to focus on historically known primary vectors. In the current study, we sought to determine the taxonomic status of samples collected from five different malaria epidemiological zones in Kenya as well asdescribe the population genetic structure and insecticide resistance profiles in relation to other An. coluzzi populations. Methods Mosquitoes were sampled as larvae from Busia, Kwale, Turkana, Kirinyaga and Kiambu counties, representing the range of malaria endemicities in Kenya, in 2019 and 2021 and emergent adults analysed using Whole Genome Sequencing data processed in accordance with the Anopheles gambiae 1000 Genomes Project phase 3. Where available, historical samples from the same sites were included for WGS. Results This study reports the detection of Anopheles coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points sampled and its presence confirmed through taxonomic analysis. Additionally, we found a lack of strong population genetic differentiation between An. coluzzii from Kenya and those from the more northerly regions of West and Central Africa, suggesting they represent a connected extension to the known species range. Mutations associated with target-site resistance to DDT and pyrethroids and metabolic resistance to DDT were found at high frequencies of ~60%. The profile and frequencies of the variants observed were similar to An. coluzzii from West and Central Africa but the ace-1 mutation linked to organophosphate and carbamate resistance present in An. coluzzii from coastal West Africa was absent in Kenya. Conclusions These findings emphasise the need for the incorporation of genomics in comprehensive and routine vector surveillance to inform on the range of malaria vector species, and their insecticide resistance status to inform the choice of effective vector control approaches.
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Affiliation(s)
- Luna Kamau
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | - Kelly L Bennett
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
| | - Eric Ochomo
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Jeremy Herren
- International Centre of Insect Physiology and Ecology
| | - Silas Agumba
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Samson Otieno
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Diana Omoke
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | | | - Joseph Mwangangi
- Centre for Geographic Medicine Research-Coast (CGMR-C), Kenya Medical Research Institute
| | - Edith Ramaita
- Ministry of Health - National Malaria Control Programme (NMCP)
| | | | | | - Sonia Barasa
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
| | - Alistair Miles
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
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Ochomo E, Rund SSC, Mthawanji RS, Antonio-Nkondjio C, Machani M, Samake S, Wolie RZ, Nsango S, Lown LA, Matoke-Muhia D, Kamau L, Lukyamuzi E, Njeri J, Chabi J, Akrofi OO, Ntege C, Mero V, Mwalimu C, Kiware S, Bilgo E, Traoré MM, Afrane Y, Hakizimana E, Muleba M, Orefuwa E, Chaki P, Juma EO. Mosquito control by abatement programmes in the United States: perspectives and lessons for countries in sub-Saharan Africa. Malar J 2024; 23:8. [PMID: 38178145 PMCID: PMC10768238 DOI: 10.1186/s12936-023-04829-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
Africa and the United States are both large, heterogeneous geographies with a diverse range of ecologies, climates and mosquito species diversity which contribute to disease transmission and nuisance biting. In the United States, mosquito control is nationally, and regionally coordinated and in so much as the Centers for Disease Control (CDC) provides guidance, the Environmental Protection Agency (EPA) provides pesticide registration, and the states provide legal authority and oversight, the implementation is usually decentralized to the state, county, or city level. Mosquito control operations are organized, in most instances, into fully independent mosquito abatement districts, public works departments, local health departments. In some cases, municipalities engage independent private contractors to undertake mosquito control within their jurisdictions. In sub-Saharan Africa (SSA), where most vector-borne disease endemic countries lie, mosquito control is organized centrally at the national level. In this model, the disease control programmes (national malaria control programmes or national malaria elimination programmes (NMCP/NMEP)) are embedded within the central governments' ministries of health (MoHs) and drive vector control policy development and implementation. Because of the high disease burden and limited resources, the primary endpoint of mosquito control in these settings is reduction of mosquito borne diseases, primarily, malaria. In the United States, however, the endpoint is mosquito control, therefore, significant (or even greater) emphasis is laid on nuisance mosquitoes as much as disease vectors. The authors detail experiences and learnings gathered by the delegation of African vector control professionals that participated in a formal exchange programme initiated by the Pan-African Mosquito Control Association (PAMCA), the University of Notre Dame, and members of the American Mosquito Control Association (AMCA), in the United States between the year 2021 and 2022. The authors highlight the key components of mosquito control operations in the United States and compare them to mosquito control programmes in SSA countries endemic for vector-borne diseases, deriving important lessons that could be useful for vector control in SSA.
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Affiliation(s)
- Eric Ochomo
- Entomology Department, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
- Vector Control Products Unit, Researchworld Limited, Kisumu, Kenya.
| | | | - Rosheen S Mthawanji
- Vector Biology Group, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Christophe Antonio-Nkondjio
- Organisation de Coordination Pour la lutte contre les Endémies en Afrique centrale (OCEAC), Yaounde, Cameroon
| | - Maxwell Machani
- Entomology Department, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - Rosine Z Wolie
- Vector Control Product Evaluation Centre - Institut Pierre Richet (VCPEC-IPR), Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire
- Unité de Formation et de Recherche des Sciences de la Nature, Université Nangui Abrogoua, Abdijan, Côte d'Ivoire
| | - Sandrine Nsango
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Centre Pasteur in Cameroon, Yaounde, Cameroon
| | | | - Damaris Matoke-Muhia
- Pan-African Mosquito Control Association (PAMCA), KEMRI Headquarters, Nairobi, Kenya
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Luna Kamau
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Edward Lukyamuzi
- Pan-African Mosquito Control Association (PAMCA), KEMRI Headquarters, Nairobi, Kenya
| | - Jane Njeri
- Pan-African Mosquito Control Association (PAMCA), KEMRI Headquarters, Nairobi, Kenya
| | | | | | - Charles Ntege
- National Malaria Control Division Ministry of Health, Kampala, Uganda
| | - Victor Mero
- Ifakara Health Institute (IHI), Dar es Salaam, Tanzania
| | | | - Samson Kiware
- Pan-African Mosquito Control Association (PAMCA), KEMRI Headquarters, Nairobi, Kenya
- Ifakara Health Institute (IHI), Dar es Salaam, Tanzania
| | - Etienne Bilgo
- Institut de Recherche en Sciences de la Sante (IRSS) Direction regionale de l'Ouest, Bobo Dioulasso, Burkina Faso
| | - Mohamed Moumine Traoré
- Malaria Research and Training Centre, Faculty of Medicine, Pharmacy and Odonto-Stomatology, University of Sciences, Techniques and Technology of Bamako, BP 1805, Bamako, Mali
| | - Yaw Afrane
- Department of Medical Microbiology, University of Ghana Medical School, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Emmanuel Hakizimana
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Centre (RBC), Ministry of Health, Kigali, Rwanda
- Pan-African Mosquito Control Organization (PAMCO), Rwanda Chapter, Kigali, Rwanda
| | | | - Emma Orefuwa
- Pan-African Mosquito Control Association (PAMCA), KEMRI Headquarters, Nairobi, Kenya
| | - Prosper Chaki
- Pan-African Mosquito Control Association (PAMCA), KEMRI Headquarters, Nairobi, Kenya
| | - Elijah Omondi Juma
- Pan-African Mosquito Control Association (PAMCA), KEMRI Headquarters, Nairobi, Kenya
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Ochomo EO, Milanoi S, Abong'o B, Onyango B, Muchoki M, Omoke D, Olanga E, Njoroge L, Juma EO, Otieno JD, Matoke-Muhia D, Kamau L, Rafferty C, Gimnig JE, Shieshia M, Wacira D, Mwangangi J, Maia M, Chege C, Omar A, Rono MK, Abel L, O'Meara WP, Obala A, Mbogo C, Kariuki L. Detection of Anopheles stephensi Mosquitoes by Molecular Surveillance, Kenya. Emerg Infect Dis 2023; 29:2498-2508. [PMID: 37966106 PMCID: PMC10683825 DOI: 10.3201/eid2912.230637] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023] Open
Abstract
The Anopheles stephensi mosquito is an invasive malaria vector recently reported in Djibouti, Ethiopia, Sudan, Somalia, Nigeria, and Ghana. The World Health Organization has called on countries in Africa to increase surveillance efforts to detect and report this vector and institute appropriate and effective control mechanisms. In Kenya, the Division of National Malaria Program conducted entomological surveillance in counties at risk for An. stephensi mosquito invasion. In addition, the Kenya Medical Research Institute conducted molecular surveillance of all sampled Anopheles mosquitoes from other studies to identify An. stephensi mosquitoes. We report the detection and confirmation of An. stephensi mosquitoes in Marsabit and Turkana Counties by using endpoint PCR and morphological and sequence identification. We demonstrate the urgent need for intensified entomological surveillance in all areas at risk for An. stephensi mosquito invasion, to clarify its occurrence and distribution and develop tailored approaches to prevent further spread.
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Kiplagat S, Villinger J, Kigen CK, Kidambasi KO, Muema JM, Mwangi SM, Wangari M, Matoke-Muhia D, Masiga DK, Bargul JL. Discovery of the vector of visceral leishmaniasis, Phlebotomus ( Artemievus) alexandri Sinton, 1928, in Kenya suggests complex transmission dynamics. Curr Res Parasitol Vector Borne Dis 2023; 4:100134. [PMID: 37593661 PMCID: PMC10428034 DOI: 10.1016/j.crpvbd.2023.100134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/12/2023] [Accepted: 07/21/2023] [Indexed: 08/19/2023]
Abstract
Visceral and cutaneous leishmaniasis are endemic to specific regions due to the ecological preferences of phlebotomine sand flies and Leishmania spp. transmission. Sand fly entomological data in northern Kenya are scarce due to limited studies and neglect of leishmaniasis. The aim of this study was to investigate: (i) sand fly diversity and distribution; (ii) occurrence of Leishmania DNA within sand flies; and (iii) blood-meal sources of sand flies in Laisamis, northern Kenya. We conducted an entomological survey during February and March of 2021 in five areas of Laisamis sub-county using standard CDC light traps. A total of 1009 sand flies (394 male and 615 female) were morphologically identified, and representative samples verified by PCR amplification and sequencing of the cytochrome c oxidase subunit 1 (cox1) gene. Similarly, we identified blood-meal sources and Leishmania DNA in female sand flies by PCR amplicon sequencing of the vertebrate cytochrome b (cyt b) gene and internal transcribed spacer 1 (ITS1) of the 28S rRNA gene, respectively. Sergentomyia clydei (59.8%) was the most abundant sand fly species. Though collected mainly from one locality (Tirgamo), 14.8% of samples belonged to Phlebotomus (Artemievus) alexandri Sinton, 1928. We detected DNA of Leishmania major in 5.19% of Ph. alexandri, whereas Leishmania adleri DNA was detected in S. clydei (7.51%), Sergentomyia squamipleuris (8.00%), and Sergentomyia africanus (8.33%). Nine of 13 blood-fed sand flies had obtained blood from humans, of which 33.3% had L. major DNA. Both Ph. alexandri and S. clydei primarily fed on humans and could potentially be involved in the transmission of cutaneous leishmaniasis. The findings of this study contribute to the understanding of sand fly vector populations and their potential to transmit leishmaniasis in the area.
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Affiliation(s)
- Steve Kiplagat
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Collins K. Kigen
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Kevin O. Kidambasi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, P.O. Box 62000-00200, Kenya
- Institute for Immunology and Infection Research, School of Biological Science, University of Edinburgh, Edinburgh, UK
| | - Jackson M. Muema
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, P.O. Box 62000-00200, Kenya
| | - Stephie M. Mwangi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Maureen Wangari
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Damaris Matoke-Muhia
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Daniel K. Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, P.O. Box 62000-00200, Kenya
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Muema JM, Bargul JL, Obonyo MA, Njeru SN, Matoke-Muhia D, Mutunga JM. Contemporary exploitation of natural products for arthropod-borne pathogen transmission-blocking interventions. Parasit Vectors 2022; 15:298. [PMID: 36002857 PMCID: PMC9404607 DOI: 10.1186/s13071-022-05367-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 02/24/2022] [Accepted: 06/16/2022] [Indexed: 11/26/2022] Open
Abstract
An integrated approach to innovatively counter the transmission of various arthropod-borne diseases to humans would benefit from strategies that sustainably limit onward passage of infective life cycle stages of pathogens and parasites to the insect vectors and vice versa. Aiming to accelerate the impetus towards a disease-free world amid the challenges posed by climate change, discovery, mindful exploitation and integration of active natural products in design of pathogen transmission-blocking interventions is of high priority. Herein, we provide a review of natural compounds endowed with blockade potential against transmissible forms of human pathogens reported in the last 2 decades from 2000 to 2021. Finally, we propose various translational strategies that can exploit these pathogen transmission-blocking natural products into design of novel and sustainable disease control interventions. In summary, tapping these compounds will potentially aid in integrated combat mission to reduce disease transmission trends.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000, Nairobi, 00200, Kenya.
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000, Nairobi, 00200, Kenya.,International Centre of Insect Physiology and Ecology (Icipe), P.O. Box 30772, Nairobi, 00100, Kenya
| | - Meshack A Obonyo
- Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, Egerton, 20115, Kenya
| | - Sospeter N Njeru
- Centre for Traditional Medicine and Drug Research (CTMDR), Kenya Medical Research Institute (KEMRI), P.O. Box 54840, Nairobi, 00200, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research Development (CBRD), Kenya Medical Research Institute (KEMRI), P.O. Box 54840, Nairobi, 00200, Kenya
| | - James M Mutunga
- Department of Biological Sciences, Mount Kenya University (MKU), P.O. Box 54, Thika, 01000, Kenya.,School of Engineering Design, Technology and Professional Programs, Pennsylvania State University, University Park, PA, 16802, USA
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Nasimiyu C, Matoke-Muhia D, Rono GK, Osoro E, Obado DO, Mwangi JM, Mwikwabe N, Thiong’o K, Dawa J, Ngere I, Gachohi J, Kariuki S, Amukoye E, Mureithi M, Ngere P, Amoth P, Were I, Makayotto L, Nene V, Abworo EO, Njenga MK, Seifert SN, Oyola SO. Imported SARS-COV-2 Variants of Concern Drove Spread of Infections Across Kenya During the Second Year of the Pandemic. medRxiv 2022:2022.02.28.22271467. [PMID: 35262086 PMCID: PMC8902869 DOI: 10.1101/2022.02.28.22271467] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Background Using classical and genomic epidemiology, we tracked the COVID-19 pandemic in Kenya over 23 months to determine the impact of SARS-CoV-2 variants on its progression. Methods SARS-CoV-2 surveillance and testing data were obtained from the Kenya Ministry of Health, collected daily from 306 health facilities. COVID-19-associated fatality data were also obtained from these health facilities and communities. Whole SARS-CoV-2 genome sequencing were carried out on 1241 specimens. Results Over the pandemic duration (March 2020 - January 2022) Kenya experienced five waves characterized by attack rates (AR) of between 65.4 and 137.6 per 100,000 persons, and intra-wave case fatality ratios (CFR) averaging 3.5%, two-fold higher than the national average COVID-19 associated CFR. The first two waves that occurred before emergence of global variants of concerns (VoC) had lower AR (65.4 and 118.2 per 100,000). Waves 3, 4, and 5 that occurred during the second year were each dominated by multiple introductions each, of Alpha (74.9% genomes), Delta (98.7%), and Omicron (87.8%) VoCs, respectively. During this phase, government-imposed restrictions failed to alleviate pandemic progression, resulting in higher attack rates spread across the country. Conclusions The emergence of Alpha, Delta, and Omicron variants was a turning point that resulted in widespread and higher SARS-CoV-2 infections across the country.
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Affiliation(s)
- Carolyne Nasimiyu
- Washington State Global Health Program-Kenya, Washington State University, Nairobi, Kenya
- Paul G. Allen School for Global Health, Washington State University, Pullman, USA
| | | | | | - Eric Osoro
- Washington State Global Health Program-Kenya, Washington State University, Nairobi, Kenya
- Paul G. Allen School for Global Health, Washington State University, Pullman, USA
| | | | | | | | | | - Jeanette Dawa
- Washington State Global Health Program-Kenya, Washington State University, Nairobi, Kenya
| | - Isaac Ngere
- Washington State Global Health Program-Kenya, Washington State University, Nairobi, Kenya
| | - John Gachohi
- Washington State Global Health Program-Kenya, Washington State University, Nairobi, Kenya
| | | | | | - Marianne Mureithi
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
| | | | | | - Ian Were
- Kenya Ministry of Health, Nairobi, Kenya
| | | | | | | | - M. Kariuki Njenga
- Washington State Global Health Program-Kenya, Washington State University, Nairobi, Kenya
- Paul G. Allen School for Global Health, Washington State University, Pullman, USA
| | - Stephanie N. Seifert
- Paul G. Allen School for Global Health, Washington State University, Pullman, USA
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Fagbamigbe AF, Tolba MF, Amankwaa EF, Mante PK, Sylverken AA, Zahouli JZB, Goonoo N, Mosi L, Oyebola K, Matoke-Muhia D, de Souza DK, Badu K, Dukhi N. Implications of WHO COVID-19 interim guideline 2020.5 on the comprehensive care for infected persons in Africa Before, during and after clinical management of cases. Sci Afr 2021; 15:e01083. [PMID: 34957351 PMCID: PMC8683379 DOI: 10.1016/j.sciaf.2021.e01083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/11/2021] [Accepted: 12/16/2021] [Indexed: 01/08/2023] Open
Abstract
The novel coronavirus disease 2019 (COVID-19) is one of the biggest public health crises globally. Although Africa did not display the worst-case scenario compared to other continents, fears were still at its peak since Africa was already suffering from a heavy load of other life-threatening infectious diseases such as HIV/AIDS and malaria. Other factors that were anticipated to complicate Africa's outcomes include the lack of resources for diagnosis and contact tracing along with the low capacity of specialized management facilities per capita. The current review aims at assessing and generating discussions on the realities, and pros and cons of the WHO COVID-19 interim guidance 2020.5 considering the known peculiarities of the African continent. A comprehensive evaluation was done for COVID-19-related data published across PubMed and Google Scholar (date of the last search: August 17, 2020) with emphasis on clinical management and psychosocial aspects. Predefined filters were then applied in data screening as detailed in the methods. Specifically, we interrogated the WHO 2020.5 guideline viz-a-viz health priority and health financing in Africa, COVID-19 case contact tracing and risk assessment, clinical management of COVID-19 cases as well as strategies for tackling stigmatization and psychosocial challenges encountered by COVID-19 survivors. The outcomes of this work provide links between these vital sub-themes which may impact the containment and management of COVID-19 cases in Africa in the long-term. The chief recommendation of the current study is the necessity of prudent filtration of the global findings along with regional modelling of the global care guidelines for acting properly in response to this health threat on the regional level without exposing our populations to further unnecessary adversities.
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Key Words
- AFCOR, Africa Task Force for Novel Coronavirus
- AIDS, acquired immune deficiency syndrome
- ARDS, acute respiratory distress syndrome
- Africa
- C02, carbon dioxide
- COVID-19
- Clinical management
- Contact tracing
- ECMO, extracorporeal membrane oxygenation
- GGE, general government expenditure
- GGHE, general government health expenditure
- H2O, Hydrogen
- HIV, Human immunodeficiency virus
- MERS, Middle East Respiratory Syndrome
- NHS, national health services
- O2, Oxygen
- PCR, polymerase chain reaction
- PTSD, post-traumatic stress disorder
- RECOVERY, Randomized Evaluation of COVID-19 Therapy
- SARS, severe acute respiratory syndrome
- Stigmatization
- US-CDC, United States Centre for Disease Control
- WHO guidelines
- WHO, World Health Organization
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Affiliation(s)
- Adeniyi Francis Fagbamigbe
- The African Academy of Sciences, Nairobi, Kenya.,Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of Medicine, University of Ibadan, Nigeria
| | - Mai F Tolba
- The African Academy of Sciences, Nairobi, Kenya.,Department of Pharmacology and Toxicology, Faculty of Pharmacy and The Centre of Drug Discovery Research and Development, Ain Shams University, Cairo 11566, Egypt.,School of Life and Medical Sciences, University of Hertfordshire Hosted by Global Academic Foundation, New Capital City, Egypt
| | - Ebenezer F Amankwaa
- The African Academy of Sciences, Nairobi, Kenya.,Department of Geography and Resource Development, University of Ghana, Accra, Ghana
| | - Priscilla Kolibea Mante
- The African Academy of Sciences, Nairobi, Kenya.,Department of Pharmacology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Augustina Angelina Sylverken
- The African Academy of Sciences, Nairobi, Kenya.,Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Ashanti, UPO/PMB, Kumasi, Ghana.,Kumasi Centre for Collaborative Research in Tropical Medicine, Kumasi, Ghana
| | - Julien Z B Zahouli
- The African Academy of Sciences, Nairobi, Kenya.,Centre d'Entomologie Médicale et Vétérinaire, Université Alassane Ouattara, Bouaké, Côte d'Ivoire
| | - Nowsheen Goonoo
- The African Academy of Sciences, Nairobi, Kenya.,Biomaterials, Drug Delivery and Nanotechnology Unit, Centre for Biomedical Biomaterials Research, University of Mauritius, Reduit, Mauritius
| | - Lydia Mosi
- The African Academy of Sciences, Nairobi, Kenya.,Department of Biochemistry Cell and Molecular Biology, University of Ghana, Ghana.,West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
| | - Kolapo Oyebola
- The African Academy of Sciences, Nairobi, Kenya.,Nigerian Institute of Medical Research, Lagos, Nigeria.,Department of Zoology, Faculty of Science, University of Lagos, Nigeria
| | - Damaris Matoke-Muhia
- The African Academy of Sciences, Nairobi, Kenya.,Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Dziedzom K de Souza
- The African Academy of Sciences, Nairobi, Kenya.,Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Kingsley Badu
- The African Academy of Sciences, Nairobi, Kenya.,Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Ashanti, UPO/PMB, Kumasi, Ghana.,Kumasi Centre for Collaborative Research in Tropical Medicine, Kumasi, Ghana
| | - Natisha Dukhi
- The African Academy of Sciences, Nairobi, Kenya.,Human and Social Capabilities Division, Human Sciences Research Council, 116-118 Buitengracht Street, Merchant House, 3rd floor, Cape Town, Western Cape 8001, South Africa
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9
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Gichuki PM, Kamau L, Njagi K, Karoki S, Muigai N, Matoke-Muhia D, Bayoh N, Mathenge E, Yadav RS. Bioefficacy and durability of Olyset ® Plus, a permethrin and piperonyl butoxide-treated insecticidal net in a 3-year long trial in Kenya. Infect Dis Poverty 2021; 10:135. [PMID: 34930459 PMCID: PMC8691082 DOI: 10.1186/s40249-021-00916-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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] [Received: 07/03/2021] [Accepted: 11/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Long-lasting insecticide nets (LLINs) are a core malaria intervention. LLINs should retain efficacy against mosquito vectors for a minimum of three years. Efficacy and durability of Olyset® Plus, a permethrin and piperonyl butoxide (PBO) treated LLIN, was evaluated versus permethrin treated Olyset® Net. In the absence of WHO guidelines of how to evaluate PBO nets, and considering the manufacturer's product claim, Olyset® Plus was evaluated as a pyrethroid LLIN. METHODS This was a household randomized controlled trial in a malaria endemic rice cultivation zone of Kirinyaga County, Kenya between 2014 and 2017. Cone bioassays and tunnel tests were done against Anopheles gambiae Kisumu. The chemical content, fabric integrity and LLIN survivorship were monitored. Comparisons between nets were tested for significance using the Chi-square test. Exact binomial distribution with 95% confidence intervals (95% CI) was used for percentages. The WHO efficacy criteria used were ≥ 95% knockdown and/or ≥ 80% mortality rate in cone bioassays and ≥ 80% mortality and/or ≥ 90% blood-feeding inhibition in tunnel tests. RESULTS At 36 months, Olyset® Plus lost 52% permethrin and 87% PBO content; Olyset® Net lost 24% permethrin. Over 80% of Olyset® Plus and Olyset® Net passed the WHO efficacy criteria for LLINs up to 18 and 12 months, respectively. At month 36, 91.2% Olyset® Plus and 86.4% Olyset® Net survived, while 72% and 63% developed at least one hole. The proportionate Hole Index (pHI) values representing nets in good, serviceable and torn condition were 49.6%, 27.1% and 23.2%, respectively for Olyset® Plus, and 44.9%, 32.8% and 22.2%, respectively for Olyset® Net but were not significantly different. CONCLUSIONS Olyset® Plus retained efficacy above or close to the WHO efficacy criteria for about 2 years than Olyset® Net (1-1.5 years). Both nets did not meet the 3-year WHO efficacy criteria, and showed little attrition, comparable physical durability and survivorship, with 50% of Olyset® Plus having good and serviceable condition after 3 years. Better community education on appropriate use and upkeep of LLINs is essential to ensure effectiveness of LLIN based malaria interventions.
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Affiliation(s)
- Paul M Gichuki
- Eastern & Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya. .,School of Health Sciences, Meru University of Science and Technology, Meru, Kenya.
| | - Luna Kamau
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Kiambo Njagi
- Division of National Malaria Programme, Ministry of Health, Nairobi, Kenya
| | - Solomon Karoki
- Division of National Malaria Programme, Ministry of Health, Nairobi, Kenya
| | - Njoroge Muigai
- Department of Health, Kirinyaga County, Kirinyaga, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Nabie Bayoh
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.,Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Evan Mathenge
- Eastern & Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Rajpal S Yadav
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
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10
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Mwagira-Maina S, Runo S, Wachira L, Kitur S, Nyasende S, Kemei B, Ochomo E, Matoke-Muhia D, Mbogo C, Kamau L. Genetic markers associated with insecticide resistance and resting behaviour in Anopheles gambiae mosquitoes in selected sites in Kenya. Malar J 2021; 20:461. [PMID: 34903240 PMCID: PMC8670025 DOI: 10.1186/s12936-021-03997-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 05/09/2021] [Accepted: 11/28/2021] [Indexed: 11/16/2022] Open
Abstract
Background Molecular diagnostic tools have been incorporated in insecticide resistance monitoring programmes to identify underlying genetic basis of resistance and develop early warning systems of vector control failure. Identifying genetic markers of insecticide resistance is crucial in enhancing the ability to mitigate potential effects of resistance. The knockdown resistance (kdr) mutation associated with resistance to DDT and pyrethroids, the acetylcholinesterase-1 (ace-1R) mutation associated with resistance to organophosphates and carbamates and 2La chromosomal inversion associated with indoor resting behaviour, were investigated in the present study. Methods Anopheles mosquitoes sampled from different sites in Kenya and collected within the context of malaria vector surveillance were analysed. Mosquitoes were collected indoors using light traps, pyrethrum spray and hand catches between August 2016 and November 2017. Mosquitoes were identified using morphological keys and Anopheles gambiae sensu lato (s.l.) mosquitoes further identified into sibling species by the polymerase chain reaction method following DNA extraction by alcohol precipitation. Anopheles gambiae and Anopheles arabiensis were analysed for the presence of the kdr and ace-1R mutations, while 2La inversion was only screened for in An. gambiae where it is polymorphic. Chi-square statistics were used to determine correlation between the 2La inversion karyotype and kdr-east mutation. Results The kdr-east mutation occurred at frequencies ranging from 0.5 to 65.6% between sites. The kdr-west mutation was only found in Migori at a total frequency of 5.3% (n = 124). No kdr mutants were detected in Tana River. The ace-1R mutation was absent in all populations. The 2La chromosomal inversion screened in An. gambiae occurred at frequencies of 87% (n = 30), 80% (n = 10) and 52% (n = 50) in Baringo, Tana River and Migori, respectively. A significant association between the 2La chromosomal inversion and the kdr-east mutation was found. Conclusion The significant association between the 2La inversion karyotype and kdr-east mutation suggests that pyrethroid resistant An. gambiae continue to rest indoors regardless of the presence of treated bed nets and residual sprays, a persistence further substantiated by studies documenting continued mosquito abundance indoors. Behavioural resistance by which Anopheles vectors prefer not to rest indoors may, therefore, not be a factor of concern in this study’s malaria vector populations.
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Affiliation(s)
- Sharon Mwagira-Maina
- Department of Biochemistry and Biotechnology, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya.
| | - Steven Runo
- Department of Biochemistry and Biotechnology, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya
| | - Lucy Wachira
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| | - Stanley Kitur
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| | - Sarah Nyasende
- Institute of Tropical Medicine and Infectious Diseases (ITROMID), P.O. Box 54840-00200, Nairobi, Kenya
| | - Brigid Kemei
- Centre for Global Health Research, KEMRI_CDC, P.O Box 1578-40100, Kisumu, Kenya
| | - Eric Ochomo
- Centre for Global Health Research, KEMRI_CDC, P.O Box 1578-40100, Kisumu, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| | - Charles Mbogo
- KEMRI -Wellcome Trust Research Programme, Public Health Unit, P.O. Box 43640-00100, Nairobi, Kenya
| | - Luna Kamau
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
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11
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Hassaballa IB, Matoke-Muhia D, Masiga DK, Sole CL, Torto B, Tchouassi DP. Behavioural responses of Phlebotomus duboscqi to plant-derived volatile organic compounds. Med Vet Entomol 2021; 35:625-632. [PMID: 34309051 DOI: 10.1111/mve.12541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 07/07/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
Phlebotomine sand flies are vectors of Leishmania parasites that cause leishmaniases. Both sexes of sand flies feed on plants primarily for sugars, although the chemical cues that mediate attraction to host plants remain largely unknown. Previously, using coupled gas chromatography-mass spectrometry, the authors identified several volatile organic compounds (VOCs) common to preferred host plants for selected Afrotropical sand flies from the Fabaceae family. Of the identified volatiles, the significance of the monoterpenes linalool oxide, ocimene and p-cymene and the benzenoid m-cresol, p-cresol in sand fly behaviour is unknown. In olfactometer assays, the authors tested these compounds singly and in blends for their attractiveness to Phlebotomus duboscqi, cutaneous leishmaniasis vector in Kenya. In dose-response assays, single compounds increased the responses of males and females over controls, but their optimum attractive doses varied between the sexes. Two five-component blends, referred to as Blend-f and Blend-m for females and males respectively, were formulated and tested in dose-response assays against 1-octen-3-ol (positive control). The results of the present study showed that males and females were significantly attracted to varying levels of the two blends. In pairwise assays, the authors evaluated the most attractive of these blends to each sex (i.e., Blend Am for male against Blend Bf for female), revealing that males were attracted to both blends at varying levels, whereas females were indifferent. The study's results demonstrate that plant-derived VOCs can be exploited for sand fly management.
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Affiliation(s)
- I B Hassaballa
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - D Matoke-Muhia
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - D K Masiga
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - C L Sole
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - B Torto
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - D P Tchouassi
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
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12
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Kimotho JH, Gosar AA, Inyangala R, Wairimu P, Siyoi F, Matoke-Muhia D, Wanjala C, Zablon J, Orina M, Muita L, Thiga J, Nyabuti L, Wainaina E, Mwangi J, Mumbi A, Omari S, Wanjiru A, Nzou SM, Ochwoto M. Pre-evaluation assessment of serological-based COVID-19 point-of-care lateral flow assays in Kenya. Afr J Lab Med 2021; 10:1317. [PMID: 34667720 PMCID: PMC8517658 DOI: 10.4102/ajlm.v10i1.1317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 06/25/2020] [Accepted: 06/23/2021] [Indexed: 11/01/2022] Open
Abstract
Background Timely testing is a key determinant of management outcomes of coronavirus disease 2019 (COVID-19). Real-time reverse transcription polymerase chain reaction tests are currently the mainstay for COVID-19 testing. However, serological point-of-care tests (PoCTs) can be useful in identifying asymptomatic and recovered cases, as well as herd immunity. Objective The aim of this study was to assess COVID-19 PoCTs in Kenya to support the emergency use authorisation of these tests. Methods Between March 2020 and May 2020, 18 firms, of which 13 were from China, submitted their PoCTs to the national regulatory authority, the Pharmacy and Poison Board, who in turn forwarded them to the Kenya Medical Research Institute for pre-evaluation assessment. The tests were run with real-time reverse transcription polymerase chain reaction COVID-19-positive samples. Pre-COVID-19 plasma samples that were collected in June 2019 were used as negative samples. The shelf lives of the PoCTs ranged from 6 to 24 months. Results Only nine (50%) tests had sensitivities ≥ 40% (range: 40% - 60%) and the ability of these tests to detect IgM ranged from 0% to 50%. Many (7/18; 38.9%) of the kits had very weak IgM and IgG band intensities (range: 2-3). Conclusion Serological-based PoCTs available in Kenya can only detect COVID-19 in up to 60% of the infected population.
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Affiliation(s)
- James H Kimotho
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Abdiaziz A Gosar
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | | | | | - Fred Siyoi
- Pharmacy and Poisons Board of Kenya, Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Centre of Biotechnology Research Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Cecilia Wanjala
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | | | - Moses Orina
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Lucy Muita
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Jacqueline Thiga
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Lameck Nyabuti
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Eunice Wainaina
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Joseph Mwangi
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Alice Mumbi
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Samuel Omari
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Ann Wanjiru
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Samson M Nzou
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
| | - Missiani Ochwoto
- Innovation Technology Transfer Division, Kenya Medical Research Institute, Nairobi, Kenya
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13
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Mosi L, Sylverken AA, Oyebola K, Badu K, Dukhi N, Goonoo N, Mante PK, Zahouli J, Amankwaa EF, Tolba MF, Fagbamigbe AF, de Souza DK, Matoke-Muhia D. Correlating WHO COVID-19 interim guideline 2020.5 and testing capacity, accuracy, and logistical challenges in Africa. Pan Afr Med J 2021; 39:89. [PMID: 34466191 PMCID: PMC8379409 DOI: 10.11604/pamj.2021.39.89.27522] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/29/2021] [Indexed: 01/08/2023] Open
Abstract
Coronavirus disease 2019 (COVID-19), a severe acute respiratory syndrome caused by SARS-CoV-2 was declared a global pandemic by the World Health Organization (WHO) in March 2020. As of 21st April 2021, the disease had affected more than 143 million people with more than 3 million deaths worldwide. Urgent effective strategies are required to control the scourge of the pandemic. Rapid sample collection and effective testing of appropriate specimens from patients meeting the suspect case definition for COVID-19 is a priority for clinical management and outbreak control. The WHO recommends that suspected cases be screened for SARS-CoV-2 virus with nucleic acid amplification tests such as real-time Reverse Transcription-Polymerase Chain Reaction (rRT-PCR). Other COVID-19 screening techniques such as serological and antigen tests have been developed and are currently being used for testing at ports of entry and for general surveillance of population exposure in some countries. However, there are limited testing options, equipment, and trained personnel in many African countries. Previously, positive patients have been screened more than twice to determine viral clearance prior to discharge after treatment. In a new policy directive, the WHO now recommends direct discharge after treatment of all positive cases without repeated testing. In this review, we discuss COVID-19 testing capacity, various diagnostic methods, test accuracy, as well as logistical challenges in Africa with respect to the WHO early discharge policy.
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Affiliation(s)
- Lydia Mosi
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, Ghana.,West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
| | - Augustina Angelina Sylverken
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Kumasi Centre for Collaborative Research in Tropical Medicine, Kumasi, Ghana.,Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Kolapo Oyebola
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Nigerian Institute of Medical Research, Lagos, Nigeria.,Department of Zoology, Faculty of Science, University of Lagos, Lagos, Nigeria
| | - Kingsley Badu
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Natisha Dukhi
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa
| | - Nowsheen Goonoo
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Biomaterials, Drug Delivery and Nanotechnology Unit, Center for Biomedical and Biomaterials Research (CBBR), University of Mauritius, MSIRI Building, 80837 Reduit, Mauritius
| | - Priscilla Kolibea Mante
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Department of Pharmacology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Julien Zahouli
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Centre Suisse de Recherches Scientifiques en Côte d´Ivoire, Abidjan, Côte d´Ivoire
| | - Ebenezer Forkuo Amankwaa
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Department of Geography and Resource Development, University of Ghana, Accra, Ghana
| | - Mai Fathy Tolba
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt.,School of Life and Medical Sciences, University of Hertfordshire hosted by Global Academic Foundation, New capital city, Egypt
| | - Adeniyi Francis Fagbamigbe
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Dziedzom Komi de Souza
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Damaris Matoke-Muhia
- African Academy of Sciences Affiliates, Nairobi, Kenya.,Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
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14
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Badu K, Oyebola K, Zahouli JZB, Fagbamigbe AF, de Souza DK, Dukhi N, Amankwaa EF, Tolba MF, Sylverken AA, Mosi L, Mante PK, Matoke-Muhia D, Goonoo N. SARS-CoV-2 Viral Shedding and Transmission Dynamics: Implications of WHO COVID-19 Discharge Guidelines. Front Med (Lausanne) 2021; 8:648660. [PMID: 34239886 PMCID: PMC8259580 DOI: 10.3389/fmed.2021.648660] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/14/2021] [Indexed: 12/20/2022] Open
Abstract
The evolving nature of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has necessitated periodic revisions of COVID-19 patient treatment and discharge guidelines. Since the identification of the first COVID-19 cases in November 2019, the World Health Organization (WHO) has played a crucial role in tackling the country-level pandemic preparedness and patient management protocols. Among others, the WHO provided a guideline on the clinical management of COVID-19 patients according to which patients can be released from isolation centers on the 10th day following clinical symptom manifestation, with a minimum of 72 additional hours following the resolution of symptoms. However, emerging direct evidence indicating the possibility of viral shedding 14 days after the onset of symptoms called for evaluation of the current WHO discharge recommendations. In this review article, we carried out comprehensive literature analysis of viral shedding with specific focus on the duration of viral shedding and infectivity in asymptomatic and symptomatic (mild, moderate, and severe forms) COVID-19 patients. Our literature search indicates that even though, there are specific instances where the current protocols may not be applicable ( such as in immune-compromised patients there is no strong evidence to contradict the current WHO discharge criteria.
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Affiliation(s)
- Kingsley Badu
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Kolapo Oyebola
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Biochemistry and Nutrition Department, Nigerian Institute of Medical Research, Lagos, Nigeria
- Department of Zoology, Faculty of Science, University of Lagos, Lagos, Nigeria
| | - Julien Z. B. Zahouli
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
- Centre d'Entomologie Médicale et Vétérinaire, Université Alassane Ouattara, Bouaké, Côte d'Ivoire
| | - Adeniyi Francis Fagbamigbe
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria
- Division of Population and Behavioral Sciences, School of Medicine, St. Andrews University, St. Andrews, United Kingdom
| | - Dziedzom K. de Souza
- African Academy of Sciences Affiliates, Nairobi, Kenya
- College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Natisha Dukhi
- African Academy of Sciences Affiliates, Nairobi, Kenya
- College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
- Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa
| | - Ebenezer F. Amankwaa
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Department of Geography and Resource Development, University of Ghana, Accra, Ghana
| | - Mai F. Tolba
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
- The Center of Drug Discovery Research and Development, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
- School of Life and Medical Sciences, University of Hertfordshire Hosted by Global Academic Foundation, New Administrative Capital, Egypt
| | - Augustina A. Sylverken
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Lydia Mosi
- African Academy of Sciences Affiliates, Nairobi, Kenya
- West African Centre for Cell Biology of Infectious Diseases, University of Ghana, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
| | - Priscilla Kolibea Mante
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Department of Pharmacology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Damaris Matoke-Muhia
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Nowsheen Goonoo
- African Academy of Sciences Affiliates, Nairobi, Kenya
- Biomaterials, Drug Delivery and Nanotechnology Unit, Center for Biomedical and Biomaterials Research (CBBR), University of Mauritius, Reduit, Mauritius
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15
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Thizy D, Pare Toe L, Mbogo C, Matoke-Muhia D, Alibu VP, Barnhill-Dilling SK, Chantler T, Chongwe G, Delborne J, Kapiriri L, Nassonko Kavuma E, Koloi-Keaikitse S, Kormos A, Littler K, Lwetoijera D, Vargas de Moraes R, Mumba N, Mutengu L, Mwichuli S, Nabukenya SE, Nakigudde J, Ndebele P, Ngara C, Ochomo E, Odiwuor Ondiek S, Rivera S, Roberts AJ, Robinson B, Sambakunsi R, Saxena A, Sykes N, Tarimo BB, Tiffin N, Tountas KH. Proceedings of an expert workshop on community agreement for gene drive research in Africa - Co-organised by KEMRI, PAMCA and Target Malaria. Gates Open Res 2021; 5:19. [PMID: 33884362 PMCID: PMC8042295 DOI: 10.12688/gatesopenres.13221.2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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] [Accepted: 02/10/2021] [Indexed: 01/02/2023] Open
Abstract
Gene drive research is progressing towards future field evaluation of modified mosquitoes for malaria control in sub-Saharan Africa. While many literature sources and guidance point to the inadequacy of individual informed consent for any genetically modified mosquito release, including gene drive ones, (outside of epidemiological studies that might require blood samples) and at the need for a community-level decision, researchers often find themselves with no specific guidance on how that decision should be made, expressed and by whom. Target Malaria, the Kenya Medical Research Institute and the Pan African Mosquito Control Association co-organised a workshop with researchers and practitioners on this topic to question the model proposed by Target Malaria in its research so far that involved the release of genetically modified sterile male mosquitoes and how this could be adapted to future studies involving gene drive mosquito releases for them to offer reflections about potential best practices. This paper shares the outcomes of that workshop and highlights the remaining topics for discussion before a comprehensive model can be designed.
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Affiliation(s)
| | - Lea Pare Toe
- Institut de Recherche en Science de la Santé, Ouagadougou, Burkina Faso
| | - Charles Mbogo
- Kenyan Institute of Medical Research, Kilifi, Kenya.,Pan African Mosquito Control Association, Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Pan African Mosquito Control Association, Nairobi, Kenya.,Kenyan Institute of Medical Research, Nairobi, Kenya
| | | | | | | | | | | | - Lydia Kapiriri
- Department of Health, Ageing and Society, McMaster University, Hamilton, Canada
| | | | | | - Ana Kormos
- University of California Irvine Malaria Initiative, Irvine, USA
| | - Katherine Littler
- Global Health Ethics Unit, World Health Organization, Geneva, Switzerland
| | | | - Roberta Vargas de Moraes
- Institute on Ethics and Policy for Innovation, Faculty of Humanities, McMaster University, Hamilton, Canada
| | - Noni Mumba
- Kenyan Institute of Medical Research, Kilifi, Kenya
| | | | - Sylvia Mwichuli
- International Center for Evaluation and Development, nairobi, Kenya
| | | | - Janet Nakigudde
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Paul Ndebele
- Milken Institute School of Public Health, George Washington University, Washington DC, USA
| | | | - Eric Ochomo
- Kenyan Institute of Medical Research, Kisumu, Kenya
| | | | - Stephany Rivera
- Institute on Ethics and Policy for Innovation, Faculty of Humanities, McMaster University, Hamilton, Canada
| | - Aaron J Roberts
- Institute on Ethics and Policy for Innovation, Faculty of Humanities, McMaster University, Hamilton, Canada
| | | | - Rodrick Sambakunsi
- Malawi Liverpool Wellcome Trust Clinical Research Program, Blantyre, Malawi
| | - Abha Saxena
- The INCLEN Trust International, Delhi, India.,Institut Ethique Histoire Humanités, University of Geneva, Geneva, Switzerland
| | | | - Brian B Tarimo
- Vector Immunity and Transmission Biology Unit, Department of Environmental Health and Ecological Sciences,, ifakara Health Institute, Bagamoyo, Tanzania
| | - Nicki Tiffin
- Division of Computational Biology, and Wellcome Centre for Infectious Disease Research in Africa, University of Cape Town, Cape Town, South Africa
| | - Karen H Tountas
- Foundation for the National Institutes of Health, Bethesda, USA
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16
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Thizy D, Pare Toe L, Mbogo C, Matoke-Muhia D, Alibu VP, Barnhill-Dilling SK, Chantler T, Chongwe G, Delborne J, Kapiriri L, Nassonko Kavuma E, Koloi-Keaikitse S, Kormos A, Littler K, Lwetoijera D, Vargas de Moraes R, Mumba N, Mutengu L, Mwichuli S, Nabukenya SE, Nakigudde J, Ndebele P, Ngara C, Ochomo E, Odiwuor Ondiek S, Rivera S, Roberts AJ, Sambakunsi R, Saxena A, Sykes N, Tarimo BB, Tiffin N, Tountas KH. Proceedings of an expert workshop on community agreement for gene drive research in Africa - Co-organised by KEMRI, PAMCA and Target Malaria. Gates Open Res 2021; 5:19. [DOI: 10.12688/gatesopenres.13221.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2021] [Indexed: 11/20/2022] Open
Abstract
Gene drive research is progressing towards future field evaluation of modified mosquitoes for malaria control in sub-Saharan Africa. While many literature sources and guidance point to the inadequacy of individual informed consent for any genetically modified mosquito release, including gene drive ones, (outside of epidemiological studies that might require blood samples) and at the need for a community-level decision, researchers often find themselves with no specific guidance on how that decision should be made, expressed and by whom. Target Malaria, the Kenya Medical Research Institute and the Pan African Mosquito Control Association co-organised a workshop with researchers and practitioners on this topic to question the model proposed by Target Malaria in its research so far that involved the release of genetically modified sterile male mosquitoes and how this could be adapted to future studies involving gene drive mosquito releases for them to offer reflections about potential best practices. This paper shares the outcomes of that workshop and highlights the remaining topics for discussion before a comprehensive model can be designed.
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Owino BO, Mwangi JM, Kiplagat S, Mwangi HN, Ingonga JM, Chebet A, Ngumbi PM, Villinger J, Masiga DK, Matoke-Muhia D. Molecular detection of Leishmania donovani, Leishmania major, and Trypanosoma species in Sergentomyia squamipleuris sand flies from a visceral leishmaniasis focus in Merti sub-County, eastern Kenya. Parasit Vectors 2021; 14:53. [PMID: 33461609 PMCID: PMC7812738 DOI: 10.1186/s13071-020-04517-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 07/25/2020] [Accepted: 12/04/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Visceral leishmaniasis (VL) and zoonotic cutaneous leishmaniasis (ZCL) are of public health concern in Merti sub-County, Kenya, but epidemiological data on transmission, vector abundance, distribution, and reservoir hosts remain limited. To better understand the disease and inform control measures to reduce transmission, we investigated the abundance and distribution of sand fly species responsible for Leishmania transmission in the sub-County and their blood-meal hosts. METHODS We conducted an entomological survey in five villages with reported cases of VL in Merti sub-County, Kenya, using CDC miniature light traps and castor oil sticky papers. Sand flies were dissected and identified to the species level using standard taxonomic keys and PCR analysis of the cytochrome c oxidase subunit 1 (cox1) gene. Leishmania parasites were detected and identified by PCR and sequencing of internal transcribed spacer 1 (ITS1) genes. Blood-meal sources of engorged females were identified by high-resolution melting analysis of vertebrate cytochrome b (cyt-b) gene PCR products. RESULTS We sampled 526 sand flies consisting of 8 species, Phlebotomus orientalis (1.52%; n = 8), and 7 Sergentomyia spp. Sergentomyia squamipleuris was the most abundant sand fly species (78.71%; n = 414) followed by Sergentomyia clydei (10.46%; n = 55). Leishmania major, Leishmania donovani, and Trypanosoma DNA were detected in S. squamipleuris specimens. Humans were the main sources of sand fly blood meals. However, we also detected mixed blood meals; one S. squamipleuris specimen had fed on both human and mouse (Mus musculus) blood, while two Ph. orientalis specimens fed on human, hyrax (Procavia capensis), and mouse (Mus musculus) blood. CONCLUSIONS Our findings implicate the potential involvement of S. squamipleuris in the transmission of Leishmania and question the dogma that human leishmaniases in the Old World are exclusively transmitted by sand flies of the Phlebotomus genus. The presence of Trypanosoma spp. may indicate mechanical transmission, whose efficiency should be investigated. Host preference analysis revealed the possibility of zoonotic transmission of leishmaniasis and other pathogens in the sub-County. Leishmania major and L. donovani are known to cause ZCL and VL, respectively. However, the reservoir status of the parasites is not uniform. Further studies are needed to determine the reservoir hosts of Leishmania spp. in the area.
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Affiliation(s)
- Barrack O Owino
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Jackline Milkah Mwangi
- Kenya Medical Research Institute, Off Mbagathi Road, P.O. Box 54840-00200, Nairobi, Kenya
| | - Steve Kiplagat
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Hannah Njiriku Mwangi
- Kenya Medical Research Institute, Off Mbagathi Road, P.O. Box 54840-00200, Nairobi, Kenya
| | - Johnstone M Ingonga
- Kenya Medical Research Institute, Off Mbagathi Road, P.O. Box 54840-00200, Nairobi, Kenya
| | - Alphine Chebet
- Kenya Medical Research Institute, Off Mbagathi Road, P.O. Box 54840-00200, Nairobi, Kenya
| | - Philip M Ngumbi
- Kenya Medical Research Institute, Off Mbagathi Road, P.O. Box 54840-00200, Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Damaris Matoke-Muhia
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya. .,Kenya Medical Research Institute, Off Mbagathi Road, P.O. Box 54840-00200, Nairobi, Kenya.
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18
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Kishoyian G, Njagi ENM, Orinda GO, Kimani FT, Thiongo K, Matoke-Muhia D. Efficacy of artemisinin-lumefantrine for treatment of uncomplicated malaria after more than a decade of its use in Kenya. Epidemiol Infect 2021; 149:e27. [PMID: 33397548 PMCID: PMC8057502 DOI: 10.1017/s0950268820003167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 12/22/2020] [Accepted: 12/22/2020] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND The resistance of Plasmodium falciparum to antimalarial drugs remains a major impairment in the treatment and eradication of malaria globally. Following the introduction of artemisinin-based combination therapy (ACT), there have been reports of delayed parasite clearance. In Kenya, artemether-lumefantrine (AL) is the recommended first-line treatment of uncomplicated malaria. This study sought to assess the efficacy of AL after a decade of use as the preferred method of managing malarial infections in Kenya. We assessed clinical and parasitological responses of children under 5 years between May and November 2015 in Chulaimbo sub-County, Kisumu, Kenya. Patients aged between 6 and 60 months with uncomplicated P. falciparum mono-infection, confirmed through microscopy, were enrolled in the study. The patients were admitted at the facility for 3 days, treated with a standard dose of AL, and then put under observation for the next 28 days for the assessment of clinical and parasitological responses. Of the 90 patients enrolled, 14 were lost to follow-up while 76 were followed through to the end of the study period. Seventy-five patients (98.7%) cleared the parasitaemia within a period of 48 h while one patient (1.3%) cleared on day 3. There was 100% adequate clinical and parasitological response. All the patients cleared the parasites on day 3 and there were no re-infections observed during the stated follow-up period. This study, therefore, concludes that AL is highly efficacious in clearing P. falciparum parasites in children aged ≥6 and ≤60 months. The study, however, underscores the need for continued monitoring of the drug to forestall both gradual ineffectiveness and possible resistance to the drug in all target users.
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Affiliation(s)
- Gabriel Kishoyian
- Department of Medical Laboratory Sciences, Kenya Medical Training College, P.O. Box2268-40100, Kisumu, Kenya
| | - Eliud N. M. Njagi
- Department of Biochemistry and Biotechnology, Kenyatta University, P.O.BOX 43844-00100, Nairobi, Kenya
| | - George O. Orinda
- Department of Biochemistry and Biotechnology, Kenyatta University, P.O.BOX 43844-00100, Nairobi, Kenya
| | - Francis T. Kimani
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Kevin Thiongo
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
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19
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Bengtson M, Bharadwaj M, Bosch AT, Nyakundi H, Matoke-Muhia D, Dekker C, Diehl JC. Matching Development of Point-of-Care Diagnostic Tests to the Local Context: A Case Study of Visceral Leishmaniasis in Kenya and Uganda. Glob Health Sci Pract 2020; 8:549-565. [PMID: 33008863 PMCID: PMC7541118 DOI: 10.9745/ghsp-d-20-00028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 08/11/2020] [Indexed: 01/18/2023]
Abstract
We provide a new protocol to connect how findings from field research on the local health care setting in resource-limited regions can inform researchers that are working toward developing a new point-of-care diagnostic test for neglected tropical diseases. The rapid growth of point-of-care (POC) diagnostic tests necessitates a clear vision of when, where, and why a new POC diagnostic test needs to be developed and how it can be used in a way that matches a local health care context. Here, we present an innovative approach toward developing a concept target product profile (CTPP), which is a new mapping tool that helps researchers match a new diagnostic test to a specific local health care context early in the research and development process. As a case study, we focus on the diagnosis of visceral leishmaniasis (VL) in rural resource-limited regions of Kenya and Uganda. Our stepwise approach integrates elements of design thinking and uses a combination of literature reviews and field research for a context analysis of local health care systems and practices. We then use visual thinking in the form of Gigamaps and patient journeys to identify use case scenarios and to present our findings from the field research to key stakeholders. The use case scenarios describe the diagnostic scope of a new POC test based on the feasibility of the new test, the local need, and the contextual fit. For our case study of VL, we identify 2 valuable use case scenarios, namely test-of-cure and screening and confirmation, and we formulate a CTPP. We anticipate that a CTPP will enable researchers to match a new POC diagnostic test during the research and development process to the local health care context in which it will be used.
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Affiliation(s)
- Michel Bengtson
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, The Netherlands
| | - Mitasha Bharadwaj
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, The Netherlands
| | - Astrid Ten Bosch
- Department of Sustainable Design Engineering, Section of Design for Sustainability, Faculty of Industrial Design Engineering, Delft University of Technology, The Netherlands
| | | | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Kenya
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, The Netherlands
| | - Jan-Carel Diehl
- Department of Sustainable Design Engineering, Section of Design for Sustainability, Faculty of Industrial Design Engineering, Delft University of Technology, The Netherlands.
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20
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Aloui-Zarrouk Z, El Youssfi L, Badu K, Francis Fagbamigbe A, Matoke-Muhia D, Ngugi C, Dukhi N, Mwaura G. The wearing of face masks in African countries under the COVID-19 crisis: luxury or necessity? AAS Open Res 2020. [DOI: 10.12688/aasopenres.13079.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The unforeseeable global crisis of the spread of coronavirus disease 2019 (COVID-19) has caused almost all affected countries to adopt a range of protective measures as recommended by the World Health Organization. However, the speed, type and level of adoption of these protective measures have been remarkably different. Social distancing and quarantine were the main measures adopted in addition to observing basic hygiene. Based on the available evidences, WHO continues to recommend wearing of face masks for healthcare workers and for those people caring for COVID-19 patients. However, some countries and organisations have recommended, and some have even made it mandatory, for their citizens to wear face masks. Particularly in low- and middle-income countries, protecting by wearing face masks is viewed as an affordable yet proactive preventive measure to avoid and slow down viral spread based on the experience of other affected countries. However, the wearing of face masks is controversial due to shortages in their stocks and uncertainty around the quality of masks, as well as their efficiency as a protective mechanism. Masks should be used based on appropriate use and management guidelines. This paper discusses the wearing of face masks from the perspective of low- and middle-income countries, particularly in Africa; and then makes some recommendations that will greatly inform policy makers on epidemic mitigation strategies throughout the African continent.
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Nambunga IH, Ngowo HS, Mapua SA, Hape EE, Msugupakulya BJ, Msaky DS, Mhumbira NT, Mchwembo KR, Tamayamali GZ, Mlembe SV, Njalambaha RM, Lwetoijera DW, Finda MF, Govella NJ, Matoke-Muhia D, Kaindoa EW, Okumu FO. Aquatic habitats of the malaria vector Anopheles funestus in rural south-eastern Tanzania. Malar J 2020; 19:219. [PMID: 32576200 PMCID: PMC7310514 DOI: 10.1186/s12936-020-03295-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/17/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND In rural south-eastern Tanzania, Anopheles funestus is a major malaria vector, and has been implicated in nearly 90% of all infective bites. Unfortunately, little is known about the natural ecological requirements and survival strategies of this mosquito species. METHODS Potential mosquito aquatic habitats were systematically searched along 1000 m transects from the centres of six villages in south-eastern Tanzania. All water bodies were geo-referenced, characterized and examined for presence of Anopheles larvae using standard 350 mLs dippers or 10 L buckets. Larvae were collected for rearing, and the emergent adults identified to confirm habitats containing An. funestus. RESULTS One hundred and eleven habitats were identified and assessed from the first five villages (all < 300 m altitude). Of these, 36 (32.4%) had An. funestus co-occurring with other mosquito species. Another 47 (42.3%) had other Anopheles species and/or culicines, but not An. funestus, and 28 (25.2%) had no mosquitoes. There were three main habitat types occupied by An. funestus, namely: (a) small spring-fed pools with well-defined perimeters (36.1%), (b) medium-sized natural ponds retaining water most of the year (16.7%), and (c) slow-moving waters along river tributaries (47.2%). The habitats generally had clear waters with emergent surface vegetation, depths > 0.5 m and distances < 100 m from human dwellings. They were permanent or semi-permanent, retaining water most of the year. Water temperatures ranged from 25.2 to 28.8 °C, pH from 6.5 to 6.7, turbidity from 26.6 to 54.8 NTU and total dissolved solids from 60.5 to 80.3 mg/L. In the sixth village (altitude > 400 m), very high densities of An. funestus were found along rivers with slow-moving clear waters and emergent vegetation. CONCLUSION This study has documented the diversity and key characteristics of aquatic habitats of An. funestus across villages in south-eastern Tanzania, and will form an important basis for further studies to improve malaria control. The observations suggest that An. funestus habitats in the area can indeed be described as fixed, few and findable based on their unique characteristics. Future studies should investigate the potential of targeting these habitats with larviciding or larval source management to complement malaria control efforts in areas dominated by this vector species.
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Affiliation(s)
- Ismail H Nambunga
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania.
| | - Halfan S Ngowo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Salum A Mapua
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme, UK
| | - Emmanuel E Hape
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Betwel J Msugupakulya
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- School of Life Science and Bioengineering, Nelson Mandela African Institution of Science & Technology, Arusha, Tanzania
| | - Dickson S Msaky
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Nicolaus T Mhumbira
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Karim R Mchwembo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Gerald Z Tamayamali
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Slyakus V Mlembe
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Rukiyah M Njalambaha
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Dickson W Lwetoijera
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- School of Life Science and Bioengineering, Nelson Mandela African Institution of Science & Technology, Arusha, Tanzania
| | - Marceline F Finda
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Park Town, Republic of South Africa
| | - Nicodem J Govella
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
- School of Life Science and Bioengineering, Nelson Mandela African Institution of Science & Technology, Arusha, Tanzania
| | - Damaris Matoke-Muhia
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Emmanuel W Kaindoa
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Park Town, Republic of South Africa
| | - Fredros O Okumu
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania.
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Park Town, Republic of South Africa.
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.
- School of Life Science and Bioengineering, Nelson Mandela African Institution of Science & Technology, Arusha, Tanzania.
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22
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Msugupakulya BJ, Kaindoa EW, Ngowo HS, Kihonda JM, Kahamba NF, Msaky DS, Matoke-Muhia D, Tungu PK, Okumu FO. Preferred resting surfaces of dominant malaria vectors inside different house types in rural south-eastern Tanzania. Malar J 2020; 19:22. [PMID: 31941508 PMCID: PMC6964015 DOI: 10.1186/s12936-020-3108-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [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] [Received: 11/28/2019] [Accepted: 01/07/2020] [Indexed: 02/04/2023] Open
Abstract
Background Malaria control in Africa relies extensively on indoor residual spraying (IRS) and insecticide-treated nets (ITNs). IRS typically targets mosquitoes resting on walls, and in few cases, roofs and ceilings, using contact insecticides. Unfortunately, little attention is paid to where malaria vectors actually rest indoors, and how such knowledge could be used to improve IRS. This study investigated preferred resting surfaces of two major malaria vectors, Anopheles funestus and Anopheles arabiensis, inside four common house types in rural south-eastern Tanzania. Methods The assessment was done inside 80 houses including: 20 with thatched roofs and mud walls, 20 with thatched roofs and un-plastered brick walls, 20 with metal roofs and un-plastered brick walls, and 20 with metal roofs and plastered brick walls, across four villages. In each house, resting mosquitoes were sampled in mornings (6 a.m.–8 a.m.), evenings (6 p.m.–8 p.m.) and at night (11 p.m.–12.00 a.m.) using Prokopack aspirators from multiple surfaces (walls, undersides of roofs, floors, furniture, utensils, clothing, curtains and bed nets). Results Overall, only 26% of An. funestus and 18% of An. arabiensis were found on walls. In grass-thatched houses, 33–55% of An. funestus and 43–50% of An. arabiensis rested under roofs, while in metal-roofed houses, only 16–20% of An. funestus and 8–30% of An. arabiensis rested under roofs. Considering all data together, approximately 40% of mosquitoes rested on surfaces not typically targeted by IRS, i.e. floors, furniture, utensils, clothing and bed nets. These proportions were particularly high in metal-roofed houses (47–53% of An. funestus; 60–66% of An. arabiensis). Conclusion While IRS typically uses contact insecticides to target adult mosquitoes on walls, and occasionally roofs and ceilings, significant proportions of vectors rest on surfaces not usually sprayed. This gap exceeds one-third of malaria mosquitoes in grass-thatched houses, and can reach two-thirds in metal-roofed houses. Where field operations exclude roofs during IRS, the gaps can be much greater. In conclusion, there is need for locally-obtained data on mosquito resting behaviours and how these influence the overall impact and costs of IRS. This study also emphasizes the need for alternative approaches, e.g. house screening, which broadly tackle mosquitoes beyond areas reachable by IRS and ITNs.
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Affiliation(s)
- Betwel J Msugupakulya
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania. .,School of Life Science and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania.
| | - Emmanuel W Kaindoa
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Halfan S Ngowo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Japhet M Kihonda
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Najat F Kahamba
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.,School of Life Science and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania
| | - Dickson S Msaky
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Damaris Matoke-Muhia
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.,Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Patrick K Tungu
- Amani Medical Research Centre, National Institute of Medical Research, Muheza, Tanzania
| | - Fredros O Okumu
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania. .,School of Life Science and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania. .,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. .,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK.
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Omondi P, Burugu M, Matoke-Muhia D, Too E, Nambati EA, Chege W, Musyoka KB, Thiongo K, Otinga M, Muregi F, Kimani F. Gametocyte clearance in children, from western Kenya, with uncomplicated Plasmodium falciparum malaria after artemether-lumefantrine or dihydroartemisinin-piperaquine treatment. Malar J 2019; 18:398. [PMID: 31801562 PMCID: PMC6891957 DOI: 10.1186/s12936-019-3032-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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] [Received: 06/10/2019] [Accepted: 11/24/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The efficacy and safety of artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) against asexual parasites population has been documented. However, the effect of these anti-malarials on sexual parasites is still less clear. Gametocyte clearance following treatment is essential for malaria control and elimination efforts; therefore, the study sought to determine trends in gametocyte clearance after AL or DP treatment in children from a malaria-endemic site in Kenya. METHODS Children aged between 0.5 and 12 years from Busia, western Kenya with uncomplicated Plasmodium falciparum malaria were assigned randomly to AL or DP treatment. A total of 334 children were enrolled, and dried blood spot samples were collected for up to 6 weeks after treatment during the peak malaria transmission season in 2016 and preserved. Plasmodium falciparum gametocytes were detected by qRT-PCR and gametocyte prevalence, density and mean duration of gametocyte carriage were determined. RESULTS At baseline, all the 334 children had positive asexual parasites by microscopy, 12% (40/334) had detectable gametocyte by microscopy, and 83.7% (253/302) children had gametocytes by RT-qPCR. Gametocyte prevalence by RT-qPCR decreased from 85.1% (126/148) at day 0 to 7.04% (5/71) at day 42 in AL group and from 82.4% (127/154) at day 0 to 14.5% (11/74) at day 42 in DP group. The average duration of gametocyte carriage as estimated by qRT-PCR was slightly shorter in the AL group (4.5 days) than in the DP group (5.1 days) but not significantly different (p = 0.301). CONCLUSION The study identifies no significant difference between AL and DP in gametocyte clearance. Gametocytes persisted up to 42 days post treatment in minority of individuals in both treatment arms. A gametocytocidal drug, in combination with artemisinin-based combination therapy, will be useful in blocking malaria transmission more efficiently.
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Affiliation(s)
- Protus Omondi
- Department of Biochemistry, Microbiology, and Biotechnology, Kenyatta University, P.O Box 43884-00100, Nairobi, Kenya.,Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Marion Burugu
- Department of Biochemistry, Microbiology, and Biotechnology, Kenyatta University, P.O Box 43884-00100, Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Edwin Too
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Eva A Nambati
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - William Chege
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Kelvin B Musyoka
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200, Nairobi, Kenya
| | - Kelvin Thiongo
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Maureen Otinga
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Francis Muregi
- Department of Biological Sciences, Mount Kenya University, P.O Box 342-00100, Nairobi, Kenya
| | - Francis Kimani
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya.
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Owino BO, Matoke-Muhia D, Alraey Y, Mwangi JM, Ingonga JM, Ngumbi PM, Casas-Sanchez A, Acosta-Serrano A, Masiga DK. Association of Phlebotomus guggisbergi with Leishmania major and Leishmania tropica in a complex transmission setting for cutaneous leishmaniasis in Gilgil, Nakuru county, Kenya. PLoS Negl Trop Dis 2019; 13:e0007712. [PMID: 31626654 PMCID: PMC6821134 DOI: 10.1371/journal.pntd.0007712] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 11/22/2018] [Revised: 10/30/2019] [Accepted: 08/15/2019] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Phlebotomus (Larroussius) guggisbergi is among the confirmed vectors for cutaneous leishmaniasis (CL) transmission in Kenya. This scarring and stigmatizing form of leishmaniasis accounts for over one million annual cases worldwide. Most recent CL epidemics in Kenya have been reported in Gilgil, Nakuru County, where the disease has become a public health issue. However, little is known about the factors that drive its transmission. Here, we sought to determine the occurrence, distribution and host blood feeding preference of the vectors, and to identify Leishmania species and infection rates in sandflies using molecular techniques. This information could lead to a better understanding of the disease transmission and improvement of control strategies in the area. METHODOLOGY/ PRINCIPAL FINDINGS An entomological survey of sandflies using CDC light traps was conducted for one week per month in April 2016, and in June and July 2017 from five villages of Gilgil, Nakuru county; Jaica, Sogonoi, Utut, Gitare and Njeru. Sandflies were identified to species level using morphological keys and further verified by PCR analysis of cytochrome c oxidase subunit I (COI) gene. Midguts of female sandflies found to harbour Leishmania were ruptured and the isolated parasites cultured in Novy-MacNeal-Nicolle (NNN) media overlaid with Schneider's insect media to identify the species. Leishmania parasite screening and identification in 198 randomly selected Phlebotomus females and parasite cultures was done by PCR-RFLP analysis of ITS1 gene, nested kDNA-PCR and real-time PCR-HRM followed by sequencing. Bloodmeal source identification was done by real-time PCR-HRM of the vertebrate cytochrome-b gene. A total of 729 sandflies (males: n = 310; females: n = 419) were collected from Utut (36.6%), Jaica (24.3%), Sogonoi (34.4%), Njeru (4.5%), and Gitare (0.1%). These were found to consist of nine species: three Phlebotomus spp. and six Sergentomyia spp. Ph. guggisbergi was the most abundant species (75.4%, n = 550) followed by Ph. saevus sensu lato (11.3%, n = 82). Sandfly species distribution across the villages was found to be significantly different (p<0.001) with Jaica recording the highest diversity. The overall Leishmania infection rate in sandflies was estimated at 7.07% (14/198). Infection rates in Ph. guggisbergi and Ph. saevus s.l. were 9.09% (12/132) and 3.57% (2/56) respectively. L. tropica was found to be the predominant parasite in Gilgil with an overall infection rate of 6.91% (13/188) in Ph. guggisbergi (n = 11) and Ph. saevus s.l. (n = 2) sandflies. However, PCR analysis also revealed L. major infection in one Ph. guggisbergi specimen. Bloodmeal analysis in the 74 blood-fed sandflies disclosed a diverse range of vertebrate hosts in Ph. guggisbergi bloodmeals, while Ph. saevus s.l. fed mainly on humans. CONCLUSIONS/ SIGNIFICANCE The high infection rates of L. tropica and abundance of Ph. guggisbergi in this study confirms this sandfly as a vector of L. tropica in Kenya. Furthermore, isolation of live L. tropica parasites from Ph. saevus s.l. suggest that there are at least three potential vectors of this parasite species in Gilgil; Ph. guggisbergi, Ph. aculeatus and Ph. saevus s.l. Molecular identification of L. major infections in Ph. guggisbergi suggested this sandfly species as a potential permissive vector of L. major, which needs to be investigated further. Sandfly host preference analysis revealed the possibility of zoonotic transmissions of L. tropica in Gilgil since the main vector (Ph. guggisbergi) does not feed exclusively on humans but also other vertebrate species. Further investigations are needed to determine the potential role of these vertebrate species in L. tropica and L. major transmission in the area.
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Affiliation(s)
- Barrack O. Owino
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Damaris Matoke-Muhia
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Yasser Alraey
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- King Khalid University, Medical Science College, Abha City, Kingdom of Saudi Arabia
| | - Jackline Milkah Mwangi
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Johnstone M. Ingonga
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Philip M. Ngumbi
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Aitor Casas-Sanchez
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Alvaro Acosta-Serrano
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Daniel K. Masiga
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
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Limwagu AJ, Kaindoa EW, Ngowo HS, Hape E, Finda M, Mkandawile G, Kihonda J, Kifungo K, Njalambaha RM, Matoke-Muhia D, Okumu FO. Using a miniaturized double-net trap (DN-Mini) to assess relationships between indoor-outdoor biting preferences and physiological ages of two malaria vectors, Anopheles arabiensis and Anopheles funestus. Malar J 2019; 18:282. [PMID: 31438957 PMCID: PMC6704488 DOI: 10.1186/s12936-019-2913-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/13/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Effective malaria surveillance requires detailed assessments of mosquitoes biting indoors, where interventions such as insecticide-treated nets work best, and outdoors, where other interventions may be required. Such assessments often involve volunteers exposing their legs to attract mosquitoes [i.e., human landing catches (HLC)], a procedure with significant safety and ethical concerns. Here, an exposure-free, miniaturized, double-net trap (DN-Mini) is used to assess relationships between indoor-outdoor biting preferences of malaria vectors, Anopheles arabiensis and Anopheles funestus, and their physiological ages (approximated by parity and insemination states). METHODS The DN-Mini is made of UV-resistant netting on a wooden frame and PVC base. At 100 cm × 60 cm × 180 cm, it fits indoors and outdoors. It has a protective inner chamber where a volunteer sits and collects host-seeking mosquitoes entrapped in an outer chamber. Experiments were conducted in eight Tanzanian villages using DN-Mini to: (a) estimate nightly biting and hourly biting proportions of mosquitoes indoors and outdoors; (b) compare these proportions to previous estimates by HLC in same villages; and, (c) compare distribution of parous (proxy for potentially infectious) and inseminated mosquitoes indoors and outdoors. RESULTS More than twice as many An. arabiensis were caught outdoors as indoors (p < 0.001), while An. funestus catches were marginally higher indoors than outdoors (p = 0.201). Anopheles arabiensis caught outdoors also had higher parity and insemination proportions than those indoors (p < 0.001), while An. funestus indoors had higher parity and insemination than those outdoors (p = 0.04). Observations of indoor-biting and outdoor-biting proportions, hourly biting patterns and overall species diversities as measured by DN-Mini, matched previous HLC estimates. CONCLUSIONS Malaria vectors that are behaviourally adapted to bite humans outdoors also have their older, potentially infectious sub-populations concentrated outdoors, while those adapted to bite indoors have their older sub-populations concentrated indoors. Here, potentially infectious An. arabiensis more likely bite outdoors than indoors, while potentially infectious An. funestus more likely bite indoors. These observations validate previous evidence that even outdoor-biting mosquitoes regularly enter houses when young. They also demonstrate efficacy of DN-Mini for measuring indoor-outdoor biting behaviours of mosquitoes, their hourly biting patterns and epidemiologically relevant parameters, e.g., parity and insemination status, without exposure to volunteers. The trap is easy-to-use, easy-to-manufacture and affordable (prototypes cost ~ 100 US$/unit).
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Affiliation(s)
- Alex J Limwagu
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.
- Department of Environmental Studies, Faculty of Science, Technology and Environmental Studies, Open University of Tanzania, Dar es Salaam, Tanzania.
| | - Emmanuel W Kaindoa
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Halfan S Ngowo
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Emmanuel Hape
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Marceline Finda
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Gustav Mkandawile
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Japhet Kihonda
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Khamis Kifungo
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Rukiyah M Njalambaha
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Damaris Matoke-Muhia
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Fredros O Okumu
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
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Onchieku NM, Mogire R, Ndung'u L, Mwitari P, Kimani F, Matoke-Muhia D, Kiboi D, Magoma G. Deciphering the targets of retroviral protease inhibitors in Plasmodium berghei. PLoS One 2018; 13:e0201556. [PMID: 30067811 PMCID: PMC6070271 DOI: 10.1371/journal.pone.0201556] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [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: 03/06/2018] [Accepted: 07/17/2018] [Indexed: 11/19/2022] Open
Abstract
Retroviral protease inhibitors (RPIs) such as lopinavir (LP) and saquinavir (SQ) are active against Plasmodium parasites. However, the exact molecular target(s) for these RPIs in the Plasmodium parasites remains poorly understood. We hypothesised that LP and SQ suppress parasite growth through inhibition of aspartyl proteases. Using reverse genetics approach, we embarked on separately generating knockout (KO) parasite lines lacking Plasmepsin 4 (PM4), PM7, PM8, or DNA damage-inducible protein 1 (Ddi1) in the rodent malaria parasite Plasmodium berghei ANKA. We then tested the suppressive profiles of the LP/Ritonavir (LP/RT) and SQ/RT as well as antimalarials; Amodiaquine (AQ) and Piperaquine (PQ) against the KO parasites in the standard 4-day suppressive test. The Ddi1 gene proved refractory to deletion suggesting that the gene is essential for the growth of the asexual blood stage parasites. Our results revealed that deletion of PM4 significantly reduces normal parasite growth rate phenotype (P = 0.003). Unlike PM4_KO parasites which were less susceptible to LP and SQ (P = 0.036, P = 0.030), the suppressive profiles for PM7_KO and PM8_KO parasites were comparable to those for the WT parasites. This finding suggests a potential role of PM4 in the LP and SQ action. On further analysis, modelling and molecular docking studies revealed that both LP and SQ displayed high binding affinities (-6.3 kcal/mol to -10.3 kcal/mol) towards the Plasmodium aspartyl proteases. We concluded that PM4 plays a vital role in assuring asexual stage parasite fitness and might be mediating LP and SQ action. The essential nature of the Ddi1 gene warrants further studies to evaluate its role in the parasite asexual blood stage growth as well as a possible target for the RPIs.
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Affiliation(s)
- Noah Machuki Onchieku
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi, Kenya
- Centre for Traditional Medicine and Drug Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Reagan Mogire
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi, Kenya
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust, Collaborative Research Program, Kilifi, Kenya
| | - Loise Ndung'u
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi, Kenya
| | - Peter Mwitari
- Centre for Traditional Medicine and Drug Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Francis Kimani
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Daniel Kiboi
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust, Collaborative Research Program, Kilifi, Kenya
- West Africa Centre for Cell Biology and Infectious Pathogens, University of Ghana, Accra, Ghana
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Gabriel Magoma
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
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Sang R, Lutomiah J, Said M, Makio A, Koka H, Koskei E, Nyunja A, Owaka S, Matoke-Muhia D, Bukachi S, Lindahl J, Grace D, Bett B. Effects of Irrigation and Rainfall on the Population Dynamics of Rift Valley Fever and Other Arbovirus Mosquito Vectors in the Epidemic-Prone Tana River County, Kenya. J Med Entomol 2017; 54:460-470. [PMID: 28011732 PMCID: PMC5850818 DOI: 10.1093/jme/tjw206] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/01/2016] [Indexed: 06/06/2023]
Abstract
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that is found in most regions of sub-Saharan Africa, and it affects humans, livestock, and some wild ungulates. Outbreaks are precipitated by an abundance of mosquito vectors associated with heavy persistent rainfall with flooding. We determined the impact of flood-irrigation farming and the effect of environmental parameters on the ecology and densities of primary and secondary vectors of the RVF virus (RVFV) in an RVF-epidemic hotspot in the Tana River Basin, Kenya. Mosquito sampling was conducted in farms and villages (settlements) in an irrigated and a neighboring nonirrigated site (Murukani). Overall, a significantly higher number of mosquitoes were collected in farms in the irrigation scheme compared with villages in the same area (P < 0.001), or farms (P < 0.001), and villages (P = 0.03) in Murukani. In particular, key primary vectors of RVFV, Aedes mcintoshi Marks and Aedes ochraceous Theobald, were more prevalent in the farms compared with villages in the irrigation scheme (P = 0.001) both during the dry and the wet seasons. Similarly, there was a greater abundance of secondary vectors, particularly Culex univittatus Theobald and Culex pipiens (L.) in the irrigation scheme than in the Murukani area. Rainfall and humidity were positively correlated with mosquito densities, particularly the primary vectors. Adult floodwater mosquitoes and Mansonia spp. were collected indoors; immatures of Ae. mcintoshi and secondary vectors were collected in the irrigation drainage canals, whereas those of Ae. ochraceous and Aedes sudanensis Theobald were missing from these water bodies. In conclusion, irrigation in RVF endemic areas provides conducive resting and breeding conditions for vectors of RVFV and other endemic arboviruses.
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Affiliation(s)
- R Sang
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54840-00200, Mbagathi Way, Nairobi, Kenya (; ; ; ; ; ; ; )
| | - J Lutomiah
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54840-00200, Mbagathi Way, Nairobi, Kenya (; ; ; ; ; ; ; )
| | - M Said
- Food Safety and Zoonosis Research Program, International Livestock Research Institute, P. O. Box 30709-00100, Nairobi, Kenya (; ; ; )
| | - A Makio
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54840-00200, Mbagathi Way, Nairobi, Kenya (; ; ; ; ; ; ; )
| | - H Koka
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54840-00200, Mbagathi Way, Nairobi, Kenya (; ; ; ; ; ; ; )
| | - E Koskei
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54840-00200, Mbagathi Way, Nairobi, Kenya (; ; ; ; ; ; ; )
| | - A Nyunja
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54840-00200, Mbagathi Way, Nairobi, Kenya (; ; ; ; ; ; ; )
| | - S Owaka
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54840-00200, Mbagathi Way, Nairobi, Kenya (; ; ; ; ; ; ; )
| | - D Matoke-Muhia
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54840-00200, Mbagathi Way, Nairobi, Kenya (; ; ; ; ; ; ; )
| | - S Bukachi
- Institute of Anthropology, University of Nairobi, P.O. Box 30079-00100, Nairobi, Kenya
| | - J Lindahl
- Food Safety and Zoonosis Research Program, International Livestock Research Institute, P. O. Box 30709-00100, Nairobi, Kenya (; ; ; )
| | - D Grace
- Food Safety and Zoonosis Research Program, International Livestock Research Institute, P. O. Box 30709-00100, Nairobi, Kenya (; ; ; )
| | - B Bett
- Food Safety and Zoonosis Research Program, International Livestock Research Institute, P. O. Box 30709-00100, Nairobi, Kenya (; ; ; )
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Matoke-Muhia D, Gimnig JE, Kamau L, Shililu J, Bayoh MN, Walker ED. Decline in frequency of the 2La chromosomal inversion in Anopheles gambiae (s.s.) in Western Kenya: correlation with increase in ownership of insecticide-treated bed nets. Parasit Vectors 2016; 9:334. [PMID: 27286834 PMCID: PMC4903000 DOI: 10.1186/s13071-016-1621-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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] [Received: 02/25/2016] [Accepted: 06/02/2016] [Indexed: 12/22/2022] Open
Abstract
Background The 2La chromosomal inversion, a genetic polymorphism in An. gambiae (sensu stricto) (s.s.), is associated with adaptation to microclimatic differences in humidity and desiccation resistance and mosquito behaviors. Ownership of insecticide-treated bed nets (ITNs) for malaria control has increased markedly in western Kenya in the last 20 years. An increase in the frequency of ITNs indoors could select against house entering or indoor resting of Anopheles mosquitoes. Thus, the frequency of the 2La inversion is postulated to change in An. gambiae (s.s.) with the increase of ITN ownership over time. Methods Anopheles gambiae mosquitoes were sampled between 1994 and 2011 using pyrethrum knockdown, bednet traps and human landing catches (HLC) from Asembo and Seme, western Kenya. The 2La inversion was detected by a PCR assay with primers designed for proximal breakpoints of the 2La/a and 2L+a/+a chromosomal conformation. Mosquitoes were tested for malaria parasite infection by sporozoite ELISA. Results The frequency of the 2La chromosomal inversion declined from 100 % of all chromosomes in 1994 to 17 % in 2005 and remained low through 2011 (21 %). ITN ownership increased from 0 to > 90 % of houses in the study area during this interval. The decline in the frequency of the 2La chromosomal inversion was significantly, negatively correlated with year (r = -0.93) and with increase in ITN ownership (r = -0.96). The frequency of the homo- and heterokaryotypes departed significantly from Hardy-Weinberg equilibrium, suggesting that 2La/a karyotype was under selection, earlier in its favor and later, against it. Precipitation and maximum monthly temperature did not vary over time, therefore there was no trend in climate that could account for the decline. There was no significant difference in frequency of the 2La inversion in An. gambiae (s.s.) females sampled indoors or outdoors in HCL in 2011, nor was there an association between the 2La inversion and infection with Plasmodium falciparum sporozoites. Conclusions The increase in ITN ownership in the study area was negatively correlated with the frequency of 2La inversion. The decline in 2La frequency in western Kenya is postulated to be due to differential impacts of ITNs on mosquitoes with different 2La karyotypes, possibly mediated by differences in behavior associated with the 2La karyotypes. Further research is required to determine if this is a widespread phenomenon, to further determine the association of the 2La karyotypes with mosquito behavior, and to assess whether ITNs are exerting selection mediated by differences in behavior on the different karyotypes.
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Affiliation(s)
- Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya. .,Institute of Tropical of Medicine and Infectious diseases, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.
| | - John E Gimnig
- Division of Parasitic Diseases and Malaria, Center for Disease Control and Prevention, Atlanta, GA, USA
| | - Luna Kamau
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Josephat Shililu
- Institute of Tropical of Medicine and Infectious diseases, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - M Nabie Bayoh
- Centers for Disease Control and Prevention, PO Box 1578, Kisumu, Kenya
| | - Edward D Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
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Kepha S, Nikolay B, Nuwaha F, Mwandawiro CS, Nankabirwa J, Ndibazza J, Cano J, Matoke-Muhia D, Pullan RL, Allen E, Halliday KE, Brooker SJ. Plasmodium falciparum parasitaemia and clinical malaria among school children living in a high transmission setting in western Kenya. Malar J 2016; 15:157. [PMID: 26969283 PMCID: PMC4788950 DOI: 10.1186/s12936-016-1176-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [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] [Received: 12/02/2015] [Accepted: 02/17/2016] [Indexed: 01/24/2023] Open
Abstract
Background Malaria among school children is increasingly receiving attention, yet the burden of malaria in this age group is poorly defined. This study presents data on malaria morbidity among school children in Bungoma county, western Kenya. Method This study investigated the burden and risk factors of Plasmodium falciparum infection, clinical malaria, and anaemia among 2346 school children aged 5–15 years, who were enrolled in an individually randomized trial evaluating the effect of anthelmintic treatment on the risks of malaria. At baseline, children were assessed for anaemia and nutritional status and information on household characteristics was collected. Children were followed-up for 13 months to assess the incidence of clinical malaria by active detection, and P. falciparum infection and density evaluated using repeated cross-sectional surveys over 15 months. Results On average prevalence of P. falciparum infection was 42 % and ranged between 32 and 48 % during the five cross-sectional surveys. Plasmodium falciparum prevalence was significantly higher among boys than girls. The overall incidence of clinical malaria was 0.26 episodes per person year (95 % confidence interval, 0.24–0.29) and was significantly higher among girls (0.23 versus 0.31, episodes per person years). Both infection prevalence and clinical disease varied by season. In multivariable analysis, P. falciparum infection was associated with being male, lower socioeconomic status and stunting. The risk of clinical malaria was associated with being female. Conclusion These findings show that the burden of P. falciparum parasitaemia, clinical malaria and anaemia among school children is not insignificant, and suggest that malaria control programmes should be expanded to include this age group. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1176-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stella Kepha
- School of Public Health, Makerere University College of Health Sciences, Kampala, Uganda.
| | - Birgit Nikolay
- London School of Hygiene and Tropical Medicine, London, UK
| | - Fred Nuwaha
- School of Public Health, Makerere University College of Health Sciences, Kampala, Uganda
| | - Charles S Mwandawiro
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Joaniter Nankabirwa
- Department of Internal Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Juliet Ndibazza
- Department of Internal Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Jorge Cano
- London School of Hygiene and Tropical Medicine, London, UK
| | | | | | | | | | - Simon J Brooker
- London School of Hygiene and Tropical Medicine, London, UK.,KEMRI-Wellcome Trust Research Programme, Nairobi, Kenya
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