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Ashine T, Eyasu A, Asmamaw Y, Simma E, Zemene E, Epstein A, Brown R, Negash N, Kochora A, Reynolds AM, Bulto MG, Tafesse T, Dagne A, Lukus B, Esayas E, Behaksra SW, Woldekidan K, Kassa FA, Deressa JD, Assefa M, Dillu D, Assefa G, Solomon H, Zeynudin A, Massebo F, Sedda L, Donnelly MJ, Wilson AL, Weetman D, Gadisa E, Yewhalaw D. Spatiotemporal distribution and bionomics of Anopheles stephensi in different eco-epidemiological settings in Ethiopia. Parasit Vectors 2024; 17:166. [PMID: 38556881 PMCID: PMC10983662 DOI: 10.1186/s13071-024-06243-3] [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: 12/22/2023] [Accepted: 03/11/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Malaria is a major public health concern in Ethiopia, and its incidence could worsen with the spread of the invasive mosquito species Anopheles stephensi in the country. This study aimed to provide updates on the distribution of An. stephensi and likely household exposure in Ethiopia. METHODS Entomological surveillance was performed in 26 urban settings in Ethiopia from 2021 to 2023. A kilometer-by-kilometer quadrant was established per town, and approximately 20 structures per quadrant were surveyed every 3 months. Additional extensive sampling was conducted in 50 randomly selected structures in four urban centers in 2022 and 2023 to assess households' exposure to An. stephensi. Prokopack aspirators and CDC light traps were used to collect adult mosquitoes, and standard dippers were used to collect immature stages. The collected mosquitoes were identified to species level by morphological keys and molecular methods. PCR assays were used to assess Plasmodium infection and mosquito blood meal source. RESULTS Catches of adult An. stephensi were generally low (mean: 0.15 per trap), with eight positive sites among the 26 surveyed. This mosquito species was reported for the first time in Assosa, western Ethiopia. Anopheles stephensi was the predominant species in four of the eight positive sites, accounting for 75-100% relative abundance of the adult Anopheles catches. Household-level exposure, defined as the percentage of households with a peridomestic presence of An. stephensi, ranged from 18% in Metehara to 30% in Danan. Anopheles arabiensis was the predominant species in 20 of the 26 sites, accounting for 42.9-100% of the Anopheles catches. Bovine blood index, ovine blood index and human blood index values were 69.2%, 32.3% and 24.6%, respectively, for An. stephensi, and 65.4%, 46.7% and 35.8%, respectively, for An. arabiensis. None of the 197 An. stephensi mosquitoes assayed tested positive for Plasmodium sporozoite, while of the 1434 An. arabiensis mosquitoes assayed, 62 were positive for Plasmodium (10 for P. falciparum and 52 for P. vivax). CONCLUSIONS This study shows that the geographical range of An. stephensi has expanded to western Ethiopia. Strongly zoophagic behavior coupled with low adult catches might explain the absence of Plasmodium infection. The level of household exposure to An. stephensi in this study varied across positive sites. Further research is needed to better understand the bionomics and contribution of An. stephensi to malaria transmission.
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Affiliation(s)
- 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.
| | - Adane Eyasu
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Yehenew Asmamaw
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Eba 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
| | - Adrienne Epstein
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Rebecca Brown
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - 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
| | - Alison M Reynolds
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | | | - Temesgen Tafesse
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Alemayehu Dagne
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Biniyam Lukus
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Endashaw Esayas
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Kidist Woldekidan
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Jimma Dinsa Deressa
- 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
| | - Dereje Dillu
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Gudissa Assefa
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Hiwot Solomon
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Ahmed Zeynudin
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Fekadu Massebo
- Department of Biology, College of Natural and Computational Sciences, Arba Minch University, Arba Minch, Ethiopia
| | - Luigi Sedda
- Lancaster Ecology and Epidemiology Group, Lancaster Medical School, Lancaster University, Lancaster, UK
| | - Martin James Donnelly
- 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
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Endalamaw Gadisa
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
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Pareyn M, Kochora A, Van Rooy L, Eligo N, Vanden Broecke B, Girma N, Merdekios B, Wegayehu T, Maes L, Caljon G, Lindtjørn B, Leirs H, Massebo F. Feeding behavior and activity of Phlebotomus pedifer and potential reservoir hosts of Leishmania aethiopica in southwestern Ethiopia. PLoS Negl Trop Dis 2020; 14:e0007947. [PMID: 32196501 PMCID: PMC7112221 DOI: 10.1371/journal.pntd.0007947] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/01/2020] [Accepted: 02/25/2020] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Cutaneous leishmaniasis (CL) is a major public health concern in Ethiopia. However, knowledge about the complex zoonotic transmission cycle is limited, hampering implementation of control strategies. We explored the feeding behavior and activity of the vector (Phlebotomus pedifer) and studied the role of livestock in CL transmission in southwestern Ethiopia. METHODS Blood meal origins of engorged sand flies were determined by sequencing host DNA. A host choice experiment was performed to assess the feeding preference of P. pedifer when humans and hyraxes are equally accessible. Ear and nose biopsies from livestock were screened for the presence of Leishmania parasites. Sand flies were captured indoor and outdoor with human landing catches and CDC light traps to determine at which time and where P. pedifer is mostly active. PRINCIPAL FINDINGS A total of 180 P. pedifer sand flies were found to bite hosts of 12 genera. Humans were the predominant blood meal source indoors (65.9%, p < 0.001), while no significant differences were determined outdoors and in caves. In caves, hyraxes were represented in blood meals equally as humans (45.5% and 42.4%, respectively), but the host choice experiment revealed that sand flies have a significant preference for feeding on hyraxes (p = 0.009). Only a single goat nose biopsy from 412 animal samples was found with Leishmania RNA. We found that P. pedifer is predominantly endophagic (p = 0.003), but occurs both indoors and outdoors. A substantial number of sand flies was active in the early evening, which increased over time reaching its maximum around midnight. CONCLUSION In contrast to earlier suggestions of exclusive zoonotic Leishmania transmission, we propose that there is also human-to-human transmission of CL in southwestern Ethiopia. Livestock does not play a role in CL transmission and combined indoor and outdoor vector control measures at night are required for efficient vector control.
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Affiliation(s)
- Myrthe Pareyn
- Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium
- * E-mail: (MP); (FM)
| | - Abena Kochora
- Biology Department, Arba Minch University, Arba Minch, Ethiopia
| | - Luca Van Rooy
- Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium
| | - Nigatu Eligo
- Biology Department, Arba Minch University, Arba Minch, Ethiopia
| | | | - Nigatu Girma
- Biology Department, Arba Minch University, Arba Minch, Ethiopia
| | - Behailu Merdekios
- Public Health Department, Arba Minch University, Arba Minch, Ethiopia
| | - Teklu Wegayehu
- Biology Department, Arba Minch University, Arba Minch, Ethiopia
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Antwerp, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Antwerp, Belgium
| | - Bernt Lindtjørn
- Centre for International Health, University of Bergen, Bergen, Norway
| | - Herwig Leirs
- Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium
| | - Fekadu Massebo
- Biology Department, Arba Minch University, Arba Minch, Ethiopia
- * E-mail: (MP); (FM)
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