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Samake JN, Athinya DK, Milanoi S, Ramaita E, Muchoki M, Omondi S, Abong'o B, Matoke-Muhia D, Mbogo C, Keitany K, Mukabana WR, Oyieke F, Shieshia M, Mburu M, Ogoma S, Nyawira E, Wekesa C, Bartilol B, Rono M, Maia M, O'Meara W, Kahindi S, Rafferty C, Schultz JS, Gutman JR, Gimnig JE, Zohdy S, Ochomo E. Spatial distribution and population structure of the invasive Anopheles stephensi in Kenya from 2022 to 2024. Sci Rep 2025; 15:19878. [PMID: 40481090 PMCID: PMC12144165 DOI: 10.1038/s41598-025-04682-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2024] [Accepted: 05/28/2025] [Indexed: 06/11/2025] Open
Abstract
This study analyzes the distribution, genetic diversity, and spread of Anopheles stephensi in Kenya following initial detection in December 2022. A total of 114 larval and 33 adult An. stephensi samples were confirmed in 7 of 18 surveyed counties majorly along transportation routes. Genetic analyses revealed three distinct genetic compositions with different levels of genetic diversity, suggesting multiple introductions into the country. The genetic composition of mosquitoes in most counties resembled southern Ethiopian populations, while those from Turkana showed a unique haplotype. A species distribution model predicts a more extensive range than currently observed, with low precipitation and minimal seasonal temperature variations as key factors influencing distribution. Challenges in adult sampling were noted, with larval sampling revealing co-occurrence with native Anopheles species. The findings have implications for surveillance and control strategies, emphasizing the need for continued monitoring, refined sampling techniques to inform bionomics, and cross-border collaboration.
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Affiliation(s)
- Jeanne N Samake
- US Centers for Disease Control and Prevention, Entomology Branch, Atlanta, GA, USA
| | - Duncan K Athinya
- Department of Biology, University of Nairobi, Nairobi, Kenya
- Vestergaard Frandsen (EA) Ltd, Nairobi, Kenya
| | - Sylvia Milanoi
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Edith Ramaita
- National Malaria Control Programme, Ministry of Health, Kenyatta National Hospital, Nairobi, Kenya
| | - Margaret Muchoki
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Seline Omondi
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Bernard Abong'o
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Charles Mbogo
- Pan African Mosquito Control Association, Nairobi, Kenya
| | - Kibor Keitany
- National Malaria Control Programme, Ministry of Health, Kenyatta National Hospital, Nairobi, Kenya
| | | | - Florence Oyieke
- Department of Biology, University of Nairobi, Nairobi, Kenya
| | - Mildred Shieshia
- US President's Malaria Initiative, US Agency for International Development, Nairobi, Kenya
| | - Monica Mburu
- PMI Evolve Kenya, Abt Global Inc., Kisumu, Kenya
| | - Sheila Ogoma
- PMI Evolve Kenya, Abt Global Inc., Kisumu, Kenya
| | | | | | | | | | - Marta Maia
- KEMRI-Wellcome Trust, Kilifi, Kenya
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | | | - Samuel Kahindi
- Department of Biological Sciences, Pwani University, Kilifi, Kenya
| | - Cristina Rafferty
- US Centers for Disease Control and Prevention, Entomology Branch, Atlanta, GA, USA
- U.S. President's Malaria Initiative, US Centers for Disease Control and Prevention, Entomology Branch, Atlanta, GA, USA
| | - Jonathan S Schultz
- US Centers for Disease Control and Prevention, Malaria Branch, Kisumu, Kenya
| | - Julie R Gutman
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
| | - John E Gimnig
- US Centers for Disease Control and Prevention, Entomology Branch, Atlanta, GA, USA
- U.S. President's Malaria Initiative, US Centers for Disease Control and Prevention, Entomology Branch, Atlanta, GA, USA
| | - Sarah Zohdy
- US Centers for Disease Control and Prevention, Entomology Branch, Atlanta, GA, USA
- U.S. President's Malaria Initiative, US Centers for Disease Control and Prevention, Entomology Branch, Atlanta, GA, USA
| | - Eric Ochomo
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
- Vector Group, Liverpool School of Tropical Medicine, Liverpool, UK.
- Centre for Infectious and Parasitic Disease Control Research, Kenya Medical Research Institute, Busia, Kenya.
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Abebe W, Sisay A, Mihret Y, Setegn A, Asmare Z, Woldesenbet D, Kassanew B, Mekuanint A, Feleke SF. Prevalence of Anopheles stephensi in Horn of Africa: a systematic review and meta-analysis. BMC Infect Dis 2025; 25:614. [PMID: 40289121 PMCID: PMC12036230 DOI: 10.1186/s12879-025-11022-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2024] [Accepted: 04/21/2025] [Indexed: 04/30/2025] Open
Abstract
BACKGROUND Anopheles stephensi has been a primary cause of malaria spread in urban areas. The World Health Organization announced a threat alert in 2019 that highlighted the An. stephensi outbreak in the Horn of Africa. Currently, there is insufficient information on the prevalence of An. stephensi. Therefore, this systematic review and meta-analysis aimed to determine the pooled prevalence of An. stephensi in Horn of Africa. METHODS Systematic search was performed to retrieve articles from PubMed, Scopus, Science Direct databases, and Google Scholar search engine. Fourteen potential studies that provided important data on An. stephensi were systematically reviewed and analyzed. The prevalence of An. stephensi was extracted separately into Microsoft Excel and analyzed using STATA 17.0. The Inverse of variance was done to evaluate heterogeneity across studies. A funnel plot and an Egger's test were used to evaluate the potential publication bias. A trim-and-fill-meta-analysis was carried out to generate a bias-adjusted effect estimate. A random effect model was used to determine the pooled prevalence of An. stephensi. Subgroup analysis was performed based on year of publication and country. RESULTS A total of 14 studies were included for this systematic review and meta-analysis. From this meta-analysis, the pooled prevalence of An. stephensi was 41.26%. The subgroup analysis based on year of publication showed that the pooled prevalence of An. stephensi in studies conducted 2014-2018 was 99%, while it was 36.82% in studies conducted 2019-2024. On the other hand, country-based analysis showed that the pooled prevalence of An. stephensi in Djibouti, Eritrea, Ethiopia, Kenya, Somaliland, and Sudan was 10.5%, 17.3%, 55.30%, 9.90%, 48.70%, and 24.63%, respectively. CONCLUSIONS This systematic review and meta-analysis reveal a high prevalence of An. stephensi across the Horn of Africa region. This underscores the significant challenges in managing malaria infections transmitted by An. stephensi in the region. Health officials must adjust current vector control measures to incorporate An. stephensi with the local malaria vector species. Also, regular identification and limiting of An. stephensi must be sustained to ensure the effectiveness of malaria prevention.
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Affiliation(s)
- Wagaw Abebe
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, P.O. Box 400, Woldia, Ethiopia.
| | - Assefa Sisay
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, P.O. Box 400, Woldia, Ethiopia
| | - Yenesew Mihret
- Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Abebaw Setegn
- Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Zelalem Asmare
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, P.O. Box 400, Woldia, Ethiopia
| | - Dagmawi Woldesenbet
- Department of Medical Laboratory Sciences, College of Medicine and Health Sciences, Wachemo University, Hossana, Ethiopia
| | - Birhanu Kassanew
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, P.O. Box 400, Woldia, Ethiopia
| | - Amare Mekuanint
- Department of Clinical Chemistry, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Sefineh Fenta Feleke
- Department of Public Health, College of health sciences, Woldia University, Woldia, Ethiopia
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Dennis TP, Sulieman JE, Abdin M, Ashine T, Asmamaw Y, Eyasu A, Simma EA, Zemene E, Negash N, Kochora A, Assefa M, Elzack HS, Dagne A, Lukas B, Bulto MG, Enayati A, Nikpoor F, Al-Nazawi AM, Al-Zahrani MH, Khaireh BA, Kayed S, Abdi AIA, Allan R, Ashraf F, Pignatelli P, Morris M, Nagi SC, Lucas ER, Hernandez-Koutoucheva A, Doumbe-Belisse P, Epstein A, Brown R, Wilson AL, Reynolds AM, Sherrard-Smith E, Yewhalaw D, Gadisa E, Malik E, Kafy HT, Donnelly MJ, Weetman D. The origin, invasion history and resistance architecture of Anopheles stephensi in Africa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.24.644828. [PMID: 40196515 PMCID: PMC11974716 DOI: 10.1101/2025.03.24.644828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 04/09/2025]
Abstract
The invasion of Africa by the Asian urban malaria vector, Anopheles stephensi, endangers 126 million people across a rapidly urbanising continent where malaria is primarily a rural disease. Control of An. stephensi requires greater understanding of its origin, invasion dynamics, and mechanisms of widespread resistance to vector control insecticides. We present a genomic surveillance study of 551 An. stephensi sampled across the invasive and native ranges in Africa and Asia. Our findings support a hypothesis that an initial invasion from Asia to Djibouti seeded separate incursions to Sudan, Ethiopia, and Yemen before spreading inland, aided by favourable temperature, vegetation cover, and human transit conditions. Insecticide resistance in invasive An. stephensi is conferred by detoxification genes introduced from Asia. These findings, and a companion genomic data catalogue, will form the foundation of an evidence base for surveillance and management strategies for An. stephensi.
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Affiliation(s)
- Tristan P.W. Dennis
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Jihad Eltaher Sulieman
- National Malaria Research & Training Centre; Sennar, Sudan
- Preventive Reference Laboratory, Health Protection and Communicable Diseases Control Dept., Ministry of Public Health;Doha, Qatar
| | - Mujahid Abdin
- Department of Community Medicine, University of Khartoum; Khartoum, Sudan
| | - Temesgen Ashine
- Department of Biology, College of Natural and Computational Sciences, Arba Minch University; Arba Minch, Ethiopia
- Malaria and NTD Research Division, Armauer Hansen Research Institute; Addis Ababa, Ethiopia
| | - Yehenew Asmamaw
- Malaria and NTD Research Division, Armauer Hansen Research Institute; Addis Ababa, Ethiopia
| | - Adane Eyasu
- Tropical and Infectious Diseases Research Center, Jimma University; Jimma, Ethiopia
| | - Eba A. Simma
- Department of Biology, College of Natural Sciences, Jimma University; Jimma, Ethiopia
| | - Endalew Zemene
- School of Medical Laboratory Sciences, Institute of Health, Jimma University; Jimma, Ethiopia
| | - Nigatu Negash
- Malaria and NTD Research Division, Armauer Hansen Research Institute; Addis Ababa, Ethiopia
| | - Abena Kochora
- Malaria and NTD Research Division, Armauer Hansen Research Institute; Addis Ababa, Ethiopia
| | - Muluken Assefa
- Malaria and NTD Research Division, Armauer Hansen Research Institute; Addis Ababa, Ethiopia
| | - Hamza Sami Elzack
- Integrated Vector Management Department, Federal Ministry of Health; Khartoum, Sudan
| | - Alemayehu Dagne
- Tropical and Infectious Diseases Research Center, Jimma University; Jimma, Ethiopia
| | - Biniam Lukas
- Tropical and Infectious Diseases Research Center, Jimma University; Jimma, Ethiopia
| | | | - Ahmadali Enayati
- School of Public Health and Health Sciences Research Center, Mazandaran University of Medical Sciences; Sari, Iran
| | - Fatemeh Nikpoor
- Malaria Control Department, Ministry of Health; Tehran, Iran
| | - Ashwaq M. Al-Nazawi
- Department of Public Health, College of Nursing and Health Sciences, Jazan University; Jazan, Saudi Arabia
- Laboratory Department, Jazan University Hospital; Jazan University, Jazan, Saudi Arabia
| | - Mohammed H. Al-Zahrani
- General Directorate of Vector-borne & Zoonotic Diseases, Ministry of Health; Riyadh, Saudi Arabia
| | - Bouh Abdi Khaireh
- Association Mutualis; Djibouti City, Djibouti
- Global Fund Program Management Unit, OGPP, Ministry of Health; Djibouti, Djibouti
| | - Samatar Kayed
- National Malaria Control Program; Djibouti City, Djibouti
| | - Abdoul-Ilah Ahmed Abdi
- Health Council of the Presidency of the Republic of Djibouti; Djibouti City, Djibouti
- Armed Forces of Djibouti Health Service; Djibouti City, Djibouti
| | | | - Faisal Ashraf
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Patricia Pignatelli
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Marion Morris
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Sanjay C. Nagi
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Eric R. Lucas
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Anastasia Hernandez-Koutoucheva
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
- Genomic Surveillance Unit, Wellcome Trust Sanger Institute; Hinxton, UK
| | | | - Adrienne Epstein
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Rebecca Brown
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Anne L. Wilson
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Alison M. Reynolds
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Ellie Sherrard-Smith
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University; Jimma, Ethiopia
- School of Medical Laboratory Sciences, Institute of Health, Jimma University; Jimma, Ethiopia
| | - Endalamaw Gadisa
- Malaria and NTD Research Division, Armauer Hansen Research Institute; Addis Ababa, Ethiopia
| | - Elfatih Malik
- Department of Community Medicine, University of Khartoum; Khartoum, Sudan
| | - Hmooda Toto Kafy
- Department of Community Medicine, University of Khartoum; Khartoum, Sudan
- Global Fund Program Management Unit, RSSH and Malaria Grant, Federal Ministry of Health; Khartoum, Sudan
| | - Martin J. Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine; Liverpool, UK
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4
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Machani MG, Onyango SA, Nzioki I, Milanoi S, Nattoh G, Githure J, Atieli H, Wang C, Lee MC, Zhou G, Githeko AK, Afrane YA, Ochomo E, Yan G. Bionomics and distribution of malaria vectors in Kisumu city, Western Kenya: implications for urban malaria transmission. Malar J 2025; 24:85. [PMID: 40089759 PMCID: PMC11909859 DOI: 10.1186/s12936-025-05332-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2024] [Accepted: 03/11/2025] [Indexed: 03/17/2025] Open
Abstract
BACKGROUND Increasing unplanned urbanization in tropical Africa may create new niches for malaria vectors, raising transmission risk, yet control efforts focus on rural ecosystems. Understanding mosquito diversity, ecology and biting behaviour in urban areas is crucial for effective control. This study assessed Anopheles diversity, abundance, behaviour, and Plasmodium infection rates in Kisumu city, Kenya. METHODS Indoor and outdoor host-seeking and resting adult mosquitoes were collected using CDC miniature light traps (CDC-LT) and Prokopack aspirators along an urban-rural transect. Anophelines were identified morphologically, with Anopheles gambiae sensu lato (s.l.) and Anopheles funestus group further distinguished to siblings using polymerase chain reaction (PCR). Sporozoite infection rates were determined using a multiplexed real-time quantitative PCR (qPCR) assay. RESULTS A total of 3,394 female Anopheles mosquitoes were collected: An. gambiae s.l. (68%), An. funestus s.l. (19.8%), Anopheles coustani (7.8%), Anopheles pharoensis (2.6%), Anopheles maculipalipis (1.6%), and Anopheles leesoni (0.2%). All six species were found in urban zone, but only three were in peri-urban and rural sites. Overall, urban collection accounted for 55.5% of mosquitoes, followed by peri-urban (30%) and rural sites (14.5%). Anopheles arabiensis dominated urban (84.3%) and peri-urban (89%) sites, while An. gambiae sensu stricto (s.s.) was predominant in rural zone (60.2%) alongside An. arabiensis (39.7%). Anopheles funestus was predominant in peri-urban (98.4%) and rural (85.7%) areas, while An. leesoni accounted for 1.6% and 14.3%, respectively. In urban areas, all An. funestus s.l. samples were An. funestus s.s.. Most (55.5%) of Anopheles mosquitoes were collected indoors, while secondary vectors were mainly outdoors. Overall, sporozoite rates were higher outdoors (3.5%) than indoors (1.45%) in rural areas. Indoor rates were 2.5% (An. funestus), 1.4% (An. gambiae s.s.), and 1% (An. arabiensis). Outdoors, An. gambiae had 5.3%, and An. arabiensis 2.1%. In peri-urban areas, An. gambiae had 2.3%. No sporozoites were found in urban samples. CONCLUSION The study highlights a shift in Anopheles diversity towards urban areas with increased outdoor activity and outdoor malaria transmission in rural and peri-urban areas, underscoring the need for tools targeting outdoor-biting mosquitoes. The presence of An. funestus in urban settings emphasizes the need for sustained entomological surveillance to inform integrated vector control.
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Affiliation(s)
- Maxwell G Machani
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
| | | | - Irene Nzioki
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Sylvia Milanoi
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Godfrey Nattoh
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
- Kaimosi Friends University, Kaimosi, Kenya
| | - John Githure
- International Center of Excellence for Malaria Research, Tom Mboya University, Homa Bay, Kenya
| | - Harrysone Atieli
- International Center of Excellence for Malaria Research, Tom Mboya University, Homa Bay, Kenya
| | - Chloe Wang
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
| | - Ming-Chieh Lee
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
| | - Goufa Zhou
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
| | - Andrew K Githeko
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Yaw A Afrane
- Department of Medical Microbiology, College of Health Sciences, University of Ghana Medical School, University of Ghana, Accra, Ghana
| | - Eric Ochomo
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
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Kimani FT, Thiongó KK, Otinga MA, Mbabu LK, Ombati MN, Kitur SK, Ochieng' SA, Wachira LN, Matoke-Muhia DK, Kamau L. Malaria prevalence, transmission potential and efficacy of artemisinin-based combination therapy in the Kenyan Central highlands: a zone previously characterized as malaria-free. Malar J 2025; 24:10. [PMID: 39800719 PMCID: PMC11726929 DOI: 10.1186/s12936-024-05214-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 12/06/2024] [Indexed: 01/16/2025] Open
Abstract
BACKGROUND The current study sought to re-evaluate malaria prevalence, susceptibility to artemisinin-based combination therapy (ACT), transmission patterns and the presence of malaria vectors in the Kikuyu area of the Kenyan Central highlands, a non-traditional/low risk malaria transmission zone where there have been anecdotal reports of emerging malaria infections. METHODS Sampling of adult mosquitoes was done indoors, while larvae were sampled outdoors in June 2019. The malaria clinical study was an open label non-randomized clinical trial where the efficacy of one ACT drug, was evaluated in two health facilities. Microscopy was used at the facility while nested 18 s rRNA subunit gene PCR amplification and MSP-1 and MSP-2 family alleles genotyping was done in the laboratory. Anti-malarial resistance gene markers Pfk13 and Pfmdr1 were profiled. RESULTS Anopheles funestus mosquitoes were the predominant vectors at 76.35% of all larvae collections (N = 148). Only two non-blood fed, parasites negative adult mosquitoes were collected from houses sampled. Parasitological analysis of the 838 patients screened resulted in 41 positives whose treatment outcome was 100% Adequate Clinical and Parasitological Response (ACPR). From the 35 positive samples genotyped, 29 (82.9%) were polyclonal. The overall mean MOI was 2.8 (95% CI 2.36-3.35). The MOI for msp-1 and msp-2 genes, was 2.02 (95% CI 0.72-2.27) and 2.9 (95% CI 2.22-3.55), and parasite strains range of 1-3 and 1-7, respectively. Polyclonal variation in the two genes was at 76.4% and 70.3%, respectively. The Pfk13 gene revealed no single nucleotide polymorphisms (SNP) associated with suspected artemisinin resistance nor was there any pfmdr1 N86 mutant allele detected. CONCLUSION The Plasmodium infections positivity rate observed in the study site was very low but significant. A proportion of participants who tested positive did not report recent history of travel. This observation together with the finding of competent known vectors can probably suggest that several of the cases could have been acquired and transmitted locally. The observed genetic diversity and polyclonal variations was on the contrary and suggest that these are imported cases. This however does not rule out a likely changing malaria transmission scenario in this zone, thus the need for further investigations.
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Affiliation(s)
- Francis T Kimani
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya.
| | - Kelvin K Thiongó
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Maureen A Otinga
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Lewis K Mbabu
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Mary N Ombati
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Stanley K Kitur
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Sarah A Ochieng'
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Lucy N Wachira
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Damaris K Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Luna Kamau
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
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6
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Doumbe Belisse P, Reynolds AM, Weetman D, Wilson AL, Donnelly MJ. A systematic review of interventions targeting Anopheles stephensi. Wellcome Open Res 2024; 9:724. [PMID: 39844918 PMCID: PMC11751610 DOI: 10.12688/wellcomeopenres.23480.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2024] [Indexed: 01/24/2025] Open
Abstract
Background Anopheles stephensi, a malaria mosquito originally from South Asia and the Middle East, has been expanding across both Asia and Africa in recent decades. The invasion of this species into sub-Saharan Africa is of particular concern given its potential to increase malaria burden, especially in urban environments where An. stephensi thrives. Whilst surveillance of this vector in Africa has recently increased markedly there is a need to review the existing methods of An. stephensi control so that we can stop, rather than simply monitor, its spread in Africa. Methods We searched published papers in PubMed using An. stephensi and intervention-specific search terms. Forty-five full-text articles were screened for eligibility and all those that reported the use of interventions against An. stephensi, and the effect on malaria incidence, malaria prevalence or vector densities were included in the analysis. All data retrieved from the literature were from the native range of An. stephensi and from the period 1995 to 2018. Results Fourteen studies which met the inclusion criteria were included in the final analysis. The vector control interventions discussed were bio larvicides (n=3), repellents (n=1), Indoor Residual Spraying (n=2), Insecticide Treated Nets (n=3), insecticide-treated materials other than nets (n=3), the combined use of repellents and mosquito nets (n=1), and combination of biolarvicide and fish (n=1). Outcomes of the studies were primarily vector density (n=10) although some reported malaria incidence and/or prevalence (n=4). Conclusions Long-lasting insecticidal nets and indoor residual spraying are effective in controlling, An. stephensi-transmitted malaria and reducing vector density, with repellents offering a complementary approach, especially in urban areas where this vector thrives. The private sector can help scale up affordable repellent production in Africa. There is a need to address gaps in cost-effectiveness analysis and gather more epidemiological evidence to better assess the impact of malaria control strategies.
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Affiliation(s)
- Patricia Doumbe Belisse
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Alison M Reynolds
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Anne L Wilson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
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7
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Zhong D, Degefa T, Zhou G, Lee MC, Wang C, Chen J, Yewhalaw D, Yan G. Esterase-Mediated Pyrethroid Resistance in Populations of an Invasive Malaria Vector Anopheles stephensi from Ethiopia. Genes (Basel) 2024; 15:1603. [PMID: 39766870 PMCID: PMC11675767 DOI: 10.3390/genes15121603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2024] [Revised: 12/09/2024] [Accepted: 12/10/2024] [Indexed: 01/11/2025] Open
Abstract
BACKGROUND The swift expansion of the invasive malaria vector Anopheles stephensi throughout Africa presents a major challenge to malaria control initiatives. Unlike the native African vectors, An. stephensi thrives in urban settings and has developed resistance to multiple classes of insecticides, including pyrethroids, organophosphates, and carbamates. METHODS Insecticide susceptibility tests were performed on field-collected An. stephensi mosquitoes from Awash Sebac Kilo, Ethiopia, to assess insecticide resistance levels. Illumina RNA-seq analysis was then employed to compare the transcriptomes of field-resistant populations and susceptible laboratory strains (STE2). RESULTS An. stephensi populations exhibited high levels of resistance to both deltamethrin (mortality, 39.4 ± 6.0%) and permethrin (mortality, 59.3 ± 26.3%) in WHO tube bioassays. RNA-seq analysis revealed that both field-resistant and field-unexposed populations exhibited increased expressions of genes associated with pyrethroid resistance, including esterases, P450s, and GSTs, compared to the susceptible STE2 strain. Notably, esterase E4 and venom carboxylesterase-6 were significantly overexpressed, up to 70-fold, compared to the laboratory strain. Functional enrichment analysis revealed a significant overrepresentation of genes associated with catalytic activity under molecular functions and metabolic process under biological process. Using weighted gene co-expression network analysis (WGCNA), we identified two co-expression modules (green and blue) that included 48 genes strongly linked to pyrethroid insecticide resistance. A co-expression network was subsequently built based on the weight values within these modules. CONCLUSIONS This study highlights the role of esterases in the pyrethroid resistance of an An. stephensi population. The identification of candidate genes associated with insecticide resistance will facilitate the development of rapid diagnostic tools to monitor resistance trends.
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Affiliation(s)
- Daibin Zhong
- Joe C. Wen School of Population & Public Health, University of California at Irvine, Irvine, CA 92697, USA; (G.Z.); (M.-C.L.); (C.W.); (J.C.); (G.Y.)
| | - Teshome Degefa
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma MVJ4+R95, Ethiopia; (T.D.); (D.Y.)
- Tropical and Infectious Diseases Research Centre (TIDRC), Jimma University, Jimma MVJ4+R95, Ethiopia
| | - Guofa Zhou
- Joe C. Wen School of Population & Public Health, University of California at Irvine, Irvine, CA 92697, USA; (G.Z.); (M.-C.L.); (C.W.); (J.C.); (G.Y.)
| | - Ming-Chieh Lee
- Joe C. Wen School of Population & Public Health, University of California at Irvine, Irvine, CA 92697, USA; (G.Z.); (M.-C.L.); (C.W.); (J.C.); (G.Y.)
| | - Chloe Wang
- Joe C. Wen School of Population & Public Health, University of California at Irvine, Irvine, CA 92697, USA; (G.Z.); (M.-C.L.); (C.W.); (J.C.); (G.Y.)
| | - Jiale Chen
- Joe C. Wen School of Population & Public Health, University of California at Irvine, Irvine, CA 92697, USA; (G.Z.); (M.-C.L.); (C.W.); (J.C.); (G.Y.)
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma MVJ4+R95, Ethiopia; (T.D.); (D.Y.)
- Tropical and Infectious Diseases Research Centre (TIDRC), Jimma University, Jimma MVJ4+R95, Ethiopia
| | - Guiyun Yan
- Joe C. Wen School of Population & Public Health, University of California at Irvine, Irvine, CA 92697, USA; (G.Z.); (M.-C.L.); (C.W.); (J.C.); (G.Y.)
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Samake JN, Yared S, Hassen MA, Zohdy S, Carter TE. Insecticide resistance and population structure of the invasive malaria vector, Anopheles stephensi, from Fiq, Ethiopia. Sci Rep 2024; 14:27516. [PMID: 39528579 PMCID: PMC11554808 DOI: 10.1038/s41598-024-78072-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 10/28/2024] [Indexed: 11/16/2024] Open
Abstract
Anopheles stephensi invasion in Ethiopia poses a risk of increased malaria disease burden in the region. Thus, understanding the insecticide resistance profile and population structure of the recently detected An. stephensi population in Fiq, Ethiopia, is critical to inform vector control to stop the spread of this invasive malaria species in the country. Following entomological surveillance for An. stephensi in Fiq, Somali region, Ethiopia, we confirmed the presence of An. stephensi morphologically and molecularly in Fiq. Characterization of larval habitats and insecticide susceptibility tests revealed that Fiq An. stephensi is most often found in artificial containers and is resistant to most adult insecticides tested (organophosphates, carbamates, pyrethroids) except for pirimiphos-methyl and PBO-pyrethroids. However, the immature larval stage was susceptible to temephos. Further comparative genomic analyses with previous An. stephensi populations from Ethiopia using 1704 biallelic SNPs revealed genetic relatedness between Fiq An. stephensi and east-central Ethiopia An. stephensi populations, particularly Jigjiga An. stephensi. Our findings of the insecticide resistance profile, coupled with the likely source population of Fiq An. stephensi, can inform vector control strategies against this malaria vector in Fiq and Jigjiga to limit further spread out of these two locations to other parts of the country and continent.
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Affiliation(s)
- Jeanne N Samake
- Department of Biology, Baylor University, Waco, TX, USA
- Entomology Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Solomon Yared
- Department of Biology, Jigjiga University, Jigjiga, Ethiopia
| | | | - Sarah Zohdy
- Entomology Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA
- U.S. President's Malaria Initiative, Entomology Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Tamar E Carter
- Department of Biology, Baylor University, Waco, TX, USA.
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Thellier M, Gemegah AAJ, Tantaoui I. Global Fight against Malaria: Goals and Achievements 1900-2022. J Clin Med 2024; 13:5680. [PMID: 39407740 PMCID: PMC11477079 DOI: 10.3390/jcm13195680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2024] [Revised: 09/17/2024] [Accepted: 09/19/2024] [Indexed: 10/20/2024] Open
Abstract
This article examines the historical and ongoing efforts to fight malaria, a parasitic disease caused by Plasmodium species and transmitted by Anopheles mosquitoes. Despite over a century of control efforts, malaria remains a major global health issue. In 2022, there were an estimated 249 million cases across 85 countries, leading to approximately 600,000 deaths. In the recently published Global Technical Strategy for Malaria 2016-2030, the World Health Organization (WHO) has prioritized malaria eradication. The main goals are to reduce malaria incidence and mortality by 90% by 2030 compared to 2015 levels. However, as of 2022, progress has been limited, with only a 2% reduction in incidence and a 6% reduction in mortality. This review traces the historical context of malaria, highlighting its ancient origins and the pivotal scientific discoveries in the late 19th century that paved the way for modern control measures. The Global Malaria Eradication Programme launched by the WHO in 1955 initially showed promise, largely due to the insecticide DDT, but ultimately failed to achieve its goals mainly due to logistical problems, vector resistance to DDT, and inadequate funding. Despite significant advances in the early 21st century, including the Roll Back Malaria initiative and increased international funding, malaria eradication remains a distant goal. Persistent challenges, such as weak healthcare systems, parasite and vector resistance to drugs and insecticides, and inadequate funding, continue to hamper global efforts. Therefore, this article underscores the need for a deeper understanding of malaria's history and recent evolution to inform future strategies for eradication.
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Affiliation(s)
- Marc Thellier
- AP-HP, Centre National de Référence du Paludisme, Hôpital Pitié–Salpêtrière, 75013 Paris, France; (A.A.J.G.); (I.T.)
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale (INSERM), IPLESP Institut Pierre–Louis d’Épidémiologie et de Santé Publique, 75013 Paris, France
| | | | - Ilhame Tantaoui
- AP-HP, Centre National de Référence du Paludisme, Hôpital Pitié–Salpêtrière, 75013 Paris, France; (A.A.J.G.); (I.T.)
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Machani MG, Onyango SA, Nzioki I, Milanoi S, Nattoh G, Githure J, Atieli H, Wang C, Lee MC, Zhou G, Githeko A, Afrane YA, Ochomo E, Yan G. Bionomics and distribution of malaria vectors in Kisumu city, Western Kenya: Implications for urban malaria transmission. RESEARCH SQUARE 2024:rs.3.rs-4943539. [PMID: 39372941 PMCID: PMC11451649 DOI: 10.21203/rs.3.rs-4943539/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/08/2024]
Abstract
Background Increasing urbanization in tropical Africa may create new niches for malaria vectors, potentially leading to higher disease transmission rates. Vector control efforts remain largely targeted at ecologically rural bio-complexities with multiple hosts. Understanding mosquito species composition, ecology, host diversity and biting behavior in urban areas is crucial for planning effective control. This study assessed mosquito species diversity, abundance, behavioral patterns, and Plasmodium sporozoite infection rates of Anopheles vectors along an urban-rural transect in Kisumu city, western Kenya. Methods Indoor and outdoor host-seeking and resting adult mosquitoes were collected using Centers for Disease Control and Prevention miniature light traps (CDC-LT) and mechanical aspirators (Prokopack) along an urban-rural transect. Females Anopheles mosquitoes collected were identified using morphological taxonomic keys to species level. Specimens belonging to the Anopheles gambiae complex and Anopheles funestus group were further processed using polymerase chain reaction (PCR) to identify members of each complex/group. Subsequently, sporozoite infection rates of the anopheline mosquitoes were determined using a multiplexed real-time quantitative PCR (qPCR) assay. Result A total of 3,394 female Anopheles mosquitoes were collected and identified. These comprised of An. gambiae s.l. (68%), An. funestus group (19.8%), An. coustani (7.8%), An. pharoensis (2.6%), An. maculipalipis (1.6%), and An. leesoni(0.2%). All six species were found in urban zone, but only three were found in peri-urban and rural sites. Overall, urban collections accounted for the majority of these collections (55.5%) of mosquitoes collected, followed by those from peri-urban (30%) and rural sites (14.5%). Species distribution across the three ecotypes showed Anopheles arabiensis was the dominant species in urban (84.3%) and peri-urban (89%) sites, while An. gambiae s.s. was predominantly found in the rural zone (60.2%) alongside An. arabiensis (39.7%). Anopheles funestus was the predominant species in peri-urban (98.4%) and rural (85.7%) areas, with An. leesoni accounted for 1.6% and 14.3%, respectively. In urban areas, all samples from the An. funestus group were identified as An. funestus s.s.. Majority (55.5%) of Anopheles mosquitoes were collected indoors, while secondary vectors were primarily caught outdoors. Overall, sporozoite rates were higher outdoors 3.5% compared to indoors 1.45% in rural areas. Specifically, sporozoite infectivity rates for An. funestus, An. gambiae s.s and An. arabiensis collected indoors in the rural zone was 2.5%, 1.4% and 1% respectively. Outdoors in rural areas, An. gambiae had a sporozoite rate of 5.3%, while An. arabiensis had a rate of 2.1%. In peri-urban areas An. gambiae had a sporozoite rate of 2.3%. No sporozoites were detected in samples from urban sites. Conclusion The study highlights a shift of diversity of Anopheles species towards urban areas with increased outdoor activity, and significant outdoor malaria transmission in rural and peri-urban areas, emphasizing the need for tools targeting outdoor-biting mosquitoes. The presence of An. funestus in urban settings is of interest and highlights the critical importance of sustained entomological surveillance to inform integrated vector control and prevent future transmission risks.
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Affiliation(s)
| | | | | | | | | | - John Githure
- International Center of Excellence for Malaria Research, Tom Mboya University, Homa Bay, Kenya
| | - Harrysone Atieli
- International Center of Excellence for Malaria Research, Tom Mboya University, Homa Bay, Kenya
| | | | | | | | | | - Yaw A Afrane
- University of Ghana Medical School, College of Health Sciences, University of Ghana, Ghana
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Rafferty C, Raise G, Scaife J, Abongo B, Omondi S, Milanoi S, Muchoki M, Onyango B, Ochomo E, Zohdy S. Loop-Mediated Isothermal Amplification Assay to Detect Invasive Malaria Vector Anopheles stephensi Mosquitoes. Emerg Infect Dis 2024; 30:1770-1778. [PMID: 38985536 PMCID: PMC11346999 DOI: 10.3201/eid3009.240444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2024] Open
Abstract
Spread of the Anopheles stephensi mosquito, an invasive malaria vector, threatens to put an additional 126 million persons per year in Africa at risk for malaria. To accelerate the early detection and rapid response to this mosquito species, confirming its presence and geographic extent is critical. However, existing molecular species assays require specialized laboratory equipment, interpretation, and sequencing confirmation. We developed and optimized a colorimetric rapid loop-mediated isothermal amplification assay for molecular An. stephensi species identification. The assay requires only a heat source and reagents and can be used with or without DNA extraction, resulting in positive color change in 30-35 minutes. We validated the assay against existing PCR techniques and found 100% specificity and analytical sensitivity down to 0.0003 ng of genomic DNA. The assay can successfully amplify single mosquito legs. Initial testing on samples from Marsabit, Kenya, illustrate its potential as an early vector detection and malaria mitigation tool.
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Nikpour F, Vatandoost H, Hanafi-Bojd AA, Raeisi A, Mirolyaie A, Mojahedi AR, Yaryan M, Banar A, Kaveh F, Abbasi M, Farmani M. Long-lasting residual efficacy of Actellic®300CS and Icon®10CS on different surfaces against Anopheles stephensi, an invasive malaria vector. Trop Med Int Health 2024; 29:781-791. [PMID: 39081142 DOI: 10.1111/tmi.14028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/03/2024]
Abstract
BACKGROUND Anopheles stephensi, a malaria-transmitting mosquito species, has developed resistance to various insecticides such as DDT, Dieldrin, Malathion, and synthetic pyrethroids. To combat this issue, the World Health Organization (WHO) suggests using Actellic®300CS and Icon®10CS for Indoor Residual Spraying to tackle pyrethroid-resistant mosquitoes. The aim of this research project was to evaluate the susceptibility of An. stephensi to certain insecticides at the diagnostic concentration + intensity 5x diagnostic concentration (5XDC) assays in Iran and to study the lasting effectiveness of Actellic®300CS and Icon®10CS against this particular malaria vector. METHODS This study assessed the susceptibility of An. stephensi populations in southern Iran to various insecticides, including deltamethrin 0.05%, DDT 4%, malathion 5%, bendiocarb 0.1%, a synergist assay with PBO 4% combined with deltamethrin 0.05%, and an intensity assay using 5x the diagnostic concentration of deltamethrin (0.25%) and bendiocarb 0.5%. Laboratory cone bioassay tests were conducted to determine the residual effectiveness of Actellic®300 and Icon®10CS insecticides on different surfaces commonly found in households, such as cement, mud, plaster, and wood. The tests were carried out following the WHO test kits and standard testing protocols. RESULTS The An. stephensi populations in Bandar Abbas were found to be susceptible to malathion 5% and deltamethrin 0.25% (5XDC), but exhibited resistance to DDT, standard concentration of deltamethrin, and both standard and intensity concentrations of bendiocarb. In laboratory cone bioassay tests, An. stephensi mortality rates when exposed to Actellic®300CS and Icon®10CS on different surfaces remained consistently more than 80%. Actellic®300CS achieved more than 80% mortality on all substrates for the entire 300-day post-spraying period. Conversely, Icon®10CS maintained mortality rates more than 80% on plaster and wood surfaces for 165 days and on mud and cement surfaces for 270 days post-spraying. Both Actellic®300CS and Icon®10CS demonstrated 100% mortality within 72 h of each test on all surfaces throughout the entire 300-day post-spraying period. CONCLUSION The study shows the varying levels of resistance of An. stephensi Bandar Abbas population to different insecticides and demonstrates the consistent performance of Actellic®300CS in controlling these mosquitoes on various surfaces. The findings suggest that long-lasting CS formulations may be more effective for malaria vector control compared to the current options. Further research is needed to validate these findings in field settings and assess the impact of these insecticides on malaria transmission.
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Affiliation(s)
- Fatemeh Nikpour
- Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
- Department of Vector-Borne Diseases, Centre for Communicable Diseases Control, Ministry of Health, Tehran, Iran
| | - Hassan Vatandoost
- Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
- Department of Vector Biology & Control of Diseases, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Ali Hanafi-Bojd
- Department of Vector Biology & Control of Diseases, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Raeisi
- Department of Vector-Borne Diseases, Centre for Communicable Diseases Control, Ministry of Health, Tehran, Iran
- Department of Vector Biology & Control of Diseases, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Abdolreza Mirolyaie
- Department of Vector-Borne Diseases, Centre for Communicable Diseases Control, Ministry of Health, Tehran, Iran
| | | | - Masoud Yaryan
- Deputy of Health, Hormozgan University of Medical Sciences, Tehran, Iran
| | - Ahad Banar
- Department of Medical Parasitology & Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Farzad Kaveh
- Department of Vector-Borne Diseases, Centre for Communicable Diseases Control, Ministry of Health, Tehran, Iran
| | - Madineh Abbasi
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mostafa Farmani
- Department of Parasitology and Mycology at the Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Taylor R, Messenger LA, Abeku TA, Clarke SE, Yadav RS, Lines J. Invasive Anopheles stephensi in Africa: insights from Asia. Trends Parasitol 2024; 40:731-743. [PMID: 39054167 DOI: 10.1016/j.pt.2024.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/03/2024] [Accepted: 06/19/2024] [Indexed: 07/27/2024]
Abstract
Anopheles stephensi is a highly competent urban malaria vector species, endemic in South Asia and the Persian Gulf, which has colonised eight countries in sub-Saharan Africa (SSA) since 2013 and is now spreading uncontrollably. In urban areas of Africa, where malaria transmission has previously been low or non-existent, the invasion of An. stephensi represents a significant problem, particularly to immunologically naïve populations. Despite this rapidly advancing threat, there is a paucity of information regarding the bionomics of An. stephensi in SSA. Here, we offer a critical synthesis of literature from An. stephensi's native range, focusing on the future of An. stephensi in a rapidly urbanising Africa, and highlighting key questions that warrant prioritisation by the global malaria vector control community.
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Affiliation(s)
- Roz Taylor
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
| | - Louisa A Messenger
- Department of Environmental and Occupational Health, School of Public Health, University of Nevada, Las Vegas, NV 89154, USA; Parasitology and Vector Biology (PARAVEC) Laboratory, School of Public Health, University of Nevada, Las Vegas, NV 89154, USA
| | - Tarekegn A Abeku
- Malaria Consortium, Green House, 244-254 Cambridge Heath Road, London E2 9DA, UK
| | - Sian E Clarke
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Rajpal S Yadav
- Academy of Public Health Entomology, Udaipur 313002, Rajasthan, India
| | - Jo Lines
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
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Arif M, Rasheed SB, Ullah H, Shah TA, Rehman FU, Dawoud TM. Feeding Behavior and Plasmodium Detection in Anopheles stephensi, a Malaria Vector in District Khyber, Khyber Pakhtunkhwa, Pakistan. IRANIAN JOURNAL OF PARASITOLOGY 2024; 19:333-340. [PMID: 39318824 PMCID: PMC11417983 DOI: 10.18502/ijpa.v19i3.16393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 06/14/2024] [Indexed: 09/26/2024]
Abstract
Background Anopheles stephensi is a significant malaria vector in Pakistan, and understanding its feeding behavior is necessary to control the spread of malaria. However, limited information is available on the host preferences of A. stephensi in Pakistan. Therefore, we aimed to explore the feeding behavior of A. stephensi, a malaria vector, in the District Khyber, Khyber Pakhtunkhwa, Pakistan. Methods A total of 7462 mosquitoes were collected between March and September 2021, with 1674 (22.4%) identified as A. stephensi (952 female and 722 male). Among the female A. stephensi, 495 (52%) were blood-fed. DNA was extracted from the blood-fed female A. stephensi mosquitoes using the Ammonium Acetate Precipitation Method followed by PCR analysis, blood meal sources were identified. Nested PCR on 191 pooled samples was used to detect Plasmodium falciparum and Plasmodium vivax. Results Cattle blood meals were predominant (73%), followed by human (20%) and chicken (7%), with no dog blood meals detected. All individual mosquito samples were negative for Plasmodium falciparum, while two pooled samples (out of 191) tested positive for P. vivax. Conclusion A. stephensi in Khyber District primarily displayed anthropophagic feeding behavior, with a small portion of the population infected with P. vivax. The results underscore the importance of targeted vector control strategies, environmental management, community engagement and continuous monitoring to suppress malaria transmission.
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Affiliation(s)
- Mahnoor Arif
- Institute of Zoological Sciences, University of Peshawar, Peshawar, Pakistan
| | - Syed Basit Rasheed
- Institute of Zoological Sciences, University of Peshawar, Peshawar, Pakistan
| | - Habib Ullah
- Institute of Zoological Sciences, University of Peshawar, Peshawar, Pakistan
| | - Tawaf Ali Shah
- College of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Faiz Ur Rehman
- Department of Zoology, Government Superior Science College Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Turki M. Dawoud
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
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Waymire E, Samake JN, Gunarathna I, Carter TE. A decade of invasive Anopheles stephensi sequence-based identification: toward a global standard. Trends Parasitol 2024; 40:477-486. [PMID: 38755024 PMCID: PMC11381088 DOI: 10.1016/j.pt.2024.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 05/18/2024]
Abstract
Anopheles stephensi is an invasive malaria vector in Africa that has been implicated in malaria outbreaks in the Horn of Africa. In 10 years, it has been detected as far east as Djibouti and as far west as Ghana. Early detections were mostly incidental, but now active surveillance in Africa has been updated to include An. stephensi. Morphological identification of An. stephensi from native vectors can be challenging, thus, sequence-based assays have been used to confirm identification during initial detections. Methods of sequence-based identification of An. stephensi have varied across initial detections to date. Here, we summarize initial detections, make suggestions that could provide a standardized approach, and discuss how sequences can inform additional genomic studies beyond species identification.
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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] [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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Omoke D, Impoinvil LM, Derilus D, Okeyo S, Saizonou H, Mulder N, Dada N, Lenhart A, Djogbénou L, Ochomo E. Whole transcriptomic analysis reveals overexpression of salivary gland and cuticular proteins genes in insecticide-resistant Anopheles arabiensis from Western Kenya. BMC Genomics 2024; 25:313. [PMID: 38532318 DOI: 10.1186/s12864-024-10182-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 03/04/2024] [Indexed: 03/28/2024] Open
Abstract
BACKGROUND Effective vector control is key to malaria prevention. However, this is now compromised by increased insecticide resistance due to continued reliance on insecticide-based control interventions. In Kenya, we have observed heterogenous resistance to pyrethroids and organophosphates in Anopheles arabiensis which is one of the most widespread malaria vectors in the country. We investigated the gene expression profiles of insecticide resistant An. arabiensis populations from Migori and Siaya counties in Western Kenya using RNA-Sequencing. Centers for Disease Control and Prevention (CDC) bottle assays were conducted using deltamethrin (DELTA), alphacypermethrin (ACYP) and pirimiphos-methyl (PMM) to determine the resistance status in both sites. RESULTS Mosquitoes from Migori had average mortalities of 91%, 92% and 58% while those from Siaya had 85%, 86%, and 30% when exposed to DELTA, ACYP and PMM, respectively. RNA-Seq analysis was done on pools of mosquitoes which survived exposure ('resistant'), mosquitoes that were not exposed, and the insecticide-susceptible An. arabiensis Dongola strain. Gene expression profiles of resistant mosquitoes from both Migori and Siaya showed an overexpression mainly of salivary gland proteins belonging to both the short and long form D7 genes, and cuticular proteins (including CPR9, CPR10, CPR15, CPR16). Additionally, the overexpression of detoxification genes including cytochrome P450s (CYP9M1, CYP325H1, CYP4C27, CYP9L1 and CYP307A1), 2 carboxylesterases and a glutathione-S-transferase (GSTE4) were also shared between DELTA, ACYP, and PMM survivors, pointing to potential contribution to cross resistance to both pyrethroid and organophosphate insecticides. CONCLUSION This study provides novel insights into the molecular basis of insecticide resistance in An. arabiensis in Western Kenya and suggests that salivary gland proteins and cuticular proteins are associated with resistance to multiple classes of insecticides.
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Affiliation(s)
- Diana Omoke
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research (CGHR), Kisumu, Kenya.
| | - Lucy Mackenzie Impoinvil
- Entomology Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, USA
| | - Dieunel Derilus
- Entomology Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, USA
| | - Stephen Okeyo
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research (CGHR), Kisumu, Kenya
| | | | | | - Nsa Dada
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Tropical Infectious Disease Research Center, University of Abomey- Calavi, Abomey Calavi, Benin
| | - Audrey Lenhart
- Entomology Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, USA
| | - Luc Djogbénou
- Entomology Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, USA
- Tropical Infectious Disease Research Center, University of Abomey- Calavi, Abomey Calavi, Benin
| | - Eric Ochomo
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research (CGHR), Kisumu, Kenya.
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18
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Meredith HR, Wesolowski A, Okoth D, Maraga L, Ambani G, Chepkwony T, Abel L, Kipkoech J, Lokoel G, Esimit D, Lokemer S, Maragia J, Prudhomme O’Meara W, Obala AA. Characterizing mobility patterns and malaria risk factors in semi-nomadic populations of Northern Kenya. PLOS GLOBAL PUBLIC HEALTH 2024; 4:e0002750. [PMID: 38478562 PMCID: PMC10936864 DOI: 10.1371/journal.pgph.0002750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/12/2024] [Indexed: 03/17/2024]
Abstract
While many studies have characterized mobility patterns and disease dynamics of settled populations, few have focused on more mobile populations. Highly mobile groups are often at higher disease risk due to their regular movement that may increase the variability of their environments, reduce their access to health care, and limit the number of intervention strategies suitable for their lifestyles. Quantifying the movements and their associated disease risks will be key to developing interventions more suitable for mobile populations. Turkana, Kenya is an ideal setting to characterize these relationships. While the vast, semi-arid county has a large mobile population (>60%) and was recently shown to have endemic malaria, the relationship between mobility and malaria risk in this region has not yet been defined. Here, we worked with 250 semi-nomadic households from four communities in Central Turkana to 1) characterize mobility patterns of travelers and 2) test the hypothesis that semi-nomadic individuals are at greater risk of malaria exposure when migrating with their herds than when staying at their semi-permanent settlements. Participants provided medical and travel histories, demographics, and a dried blood spot for malaria testing before and after the travel period. Further, a subset of travelers was given GPS loggers to document their routes. Four travel patterns emerged from the logger data, Long Term, Transient, Day trip, and Static, with only Long Term and Transient trips being associated with malaria cases detected in individuals who carried GPS devices. After completing their trips, travelers had a higher prevalence of malaria than those who remained at the household (9.2% vs 4.4%), regardless of gender and age. These findings highlight the need to develop intervention strategies amenable to mobile lifestyles that can ultimately help prevent the transmission of malaria.
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Affiliation(s)
- Hannah R. Meredith
- Duke Global Health Institute, Durham, North Carolina, United States of America
| | - Amy Wesolowski
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Dennis Okoth
- Department of Health Services and Sanitation, Lodwar, Turkana County, Kenya
| | - Linda Maraga
- Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - George Ambani
- Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | | | - Lucy Abel
- Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - Joseph Kipkoech
- Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - Gilchrist Lokoel
- Department of Health Services and Sanitation, Lodwar, Turkana County, Kenya
| | - Daniel Esimit
- Department of Health Services and Sanitation, Lodwar, Turkana County, Kenya
| | - Samuel Lokemer
- Department of Health Services and Sanitation, Lodwar, Turkana County, Kenya
| | - James Maragia
- Department of Health Services and Sanitation, Lodwar, Turkana County, Kenya
| | - Wendy Prudhomme O’Meara
- Duke Global Health Institute, Durham, North Carolina, United States of America
- School of Public Health, Moi University College of Health Sciences, Eldoret, Kenya
- School of Medicine, Duke University, Durham, North Carolina, United States of America
| | - Andrew A. Obala
- School of Medicine, Moi University College of Health Sciences, Eldoret, Kenya
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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. RESEARCH SQUARE 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] [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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20
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Hawaria D, Kibret S, Zhong D, Lee MC, Lelisa K, Bekele B, Birhanu M, Mengesha M, Solomon H, Yewhalaw D, Yan G. First report of Anopheles stephensi from southern Ethiopia. Malar J 2023; 22:373. [PMID: 38066610 PMCID: PMC10704791 DOI: 10.1186/s12936-023-04813-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 12/02/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Anopheles stephensi is an emerging exotic invasive urban malaria vector in East Africa. The World Health Organization recently announced an initiative to take concerted actions to limit this vector's expansion by strengthening surveillance and control in invaded and potentially receptive territories in Africa. This study sought to determine the invasion of An. stephensi in southern Ethiopia. METHODS A targeted entomological survey, both larvae and adult, was conducted in Hawassa City, southern Ethiopia between November 2022 and February 2023. Anopheles larvae were reared to adults for species identification. CDC light traps and BG Pro traps were used indoors and outdoors overnight at selected houses to collect adult mosquitoes in the study area. Prokopack aspirator was employed to sample indoor resting mosquitoes in the morning. Adults of An. stephensi was identified using morphological keys and then confirmed by PCR. RESULTS Larvae of An. stephensi were found in 28 (16.6%) of the 169 potential mosquito breeding sites surveyed. Out of 548 adult female Anopheles mosquitoes reared from larvae, 234 (42.7%) were identified as An. stephensi morphologically. A total of 449 female anophelines were caught, of which 53 (12.0%) were An. stephensi. Other anopheline species collected in the study area included Anopheles gambiae sensu lato (s.l.), Anopheles pharoensis, Anopheles coustani, and Anopheles demeilloni. CONCLUSION This study confirmed the presence of An. stephensi in southern Ethiopia. The presence of both larval and adult stages of this mosquito attests that this species established sympatric colonization with native vector species such as An. gambiae (s.l.) in southern Ethiopia. The findings warrant further investigation on the ecology, behaviour, population genetics, and role of An. stephensi in malaria transmission in Ethiopia.
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Affiliation(s)
- Dawit Hawaria
- School of Environmental Health, Hawassa University, Hawassa, Ethiopia.
| | - Solomon Kibret
- West Valley Mosquito and Vector Control District, Ontario, CA, USA
| | - Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, CA, 92697, USA
| | - Ming-Chieh Lee
- Program in Public Health, University of California at Irvine, Irvine, CA, 92697, USA
| | - Kidane Lelisa
- Department of Biology, Dilla University, Dilla, Ethiopia
| | - Belayneh Bekele
- Disease Prevention Department, Sidama Regional Health Bureau, Hawassa, Ethiopia
| | - Muntasha Birhanu
- Hawassa City Administration Health Department, Hawassa, Ethiopia
| | - Mathe Mengesha
- Sidama Regional Public Health Institute, Hawassa, Ethiopia
| | | | - Delenesaw Yewhalaw
- Tropical and Infectious Diseases Research Centre (TIDRC), Jimma University, Jimma, Ethiopia
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA, 92697, USA
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