Changes in contributions of different Anopheles vector species to malaria transmission in east and southern Africa from 2000 to 2022
Abstract Background Malaria transmission in Africa is facilitated by multiple species of Anopheles mosquitoes. These vectors have different behaviors and vectorial capacities and are affected differently by vector control interventions, such as insecticide-treated nets and indoor residual spraying....
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| Format: | Article |
| Language: | English |
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BMC
2023-11-01
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| Series: | Parasites & Vectors |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13071-023-06019-1 |
| _version_ | 1797630370405941248 |
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| author | Betwel J. Msugupakulya Naomi H. Urio Mohammed Jumanne Halfan S. Ngowo Prashanth Selvaraj Fredros O. Okumu Anne L. Wilson |
| author_facet | Betwel J. Msugupakulya Naomi H. Urio Mohammed Jumanne Halfan S. Ngowo Prashanth Selvaraj Fredros O. Okumu Anne L. Wilson |
| author_sort | Betwel J. Msugupakulya |
| collection | DOAJ |
| description | Abstract Background Malaria transmission in Africa is facilitated by multiple species of Anopheles mosquitoes. These vectors have different behaviors and vectorial capacities and are affected differently by vector control interventions, such as insecticide-treated nets and indoor residual spraying. This review aimed to assess changes in the contribution of different vector species to malaria transmission in east and southern Africa over 20 years of widespread insecticide-based vector control. Methods We searched PubMed, Global Health, and Web of Science online databases for articles published between January 2000 and April 2023 that provided species-specific sporozoite rates for different malaria vectors in east and southern Africa. We extracted data on study characteristics, biting rates, sporozoite infection proportions, and entomological inoculation rates (EIR). Using EIR data, the proportional contribution of each species to malaria transmission was estimated. Results Studies conducted between 2000 and 2010 identified the Anopheles gambiae complex as the primary malaria vector, while studies conducted from 2011 to 2021 indicated the dominance of Anopheles funestus. From 2000 to 2010, in 57% of sites, An. gambiae demonstrated higher parasite infection prevalence than other Anopheles species. Anopheles gambiae also accounted for over 50% of EIR in 76% of the study sites. Conversely, from 2011 to 2021, An. funestus dominated with higher infection rates than other Anopheles in 58% of sites and a majority EIR contribution in 63% of sites. This trend coincided with a decline in overall EIR and the proportion of sporozoite-infected An. gambiae. The main vectors in the An. gambiae complex in the region were Anopheles arabiensis and An. gambiae sensu stricto (s.s.), while the important member of the An. funestus group was An. funestus s.s. Conclusion The contribution of different vector species in malaria transmission has changed over the past 20 years. As the role of An. gambiae has declined, An. funestus now appears to be dominant in most settings in east and southern Africa. Other secondary vector species may play minor roles in specific localities. To improve malaria control in the region, vector control should be optimized to match these entomological trends, considering the different ecologies and behaviors of the dominant vector species. Graphical Abstract |
| first_indexed | 2024-03-11T11:07:24Z |
| format | Article |
| id | doaj.art-5176462ef3d34ce488edbf00b8cbd48b |
| institution | Directory Open Access Journal |
| issn | 1756-3305 |
| language | English |
| last_indexed | 2024-03-11T11:07:24Z |
| publishDate | 2023-11-01 |
| publisher | BMC |
| record_format | Article |
| series | Parasites & Vectors |
| spelling | doaj.art-5176462ef3d34ce488edbf00b8cbd48b2023-11-12T12:08:11ZengBMCParasites & Vectors1756-33052023-11-0116111610.1186/s13071-023-06019-1Changes in contributions of different Anopheles vector species to malaria transmission in east and southern Africa from 2000 to 2022Betwel J. Msugupakulya0Naomi H. Urio1Mohammed Jumanne2Halfan S. Ngowo3Prashanth Selvaraj4Fredros O. Okumu5Anne L. Wilson6Environmental Health and Ecological Sciences Department, Ifakara Health InstituteEnvironmental Health and Ecological Sciences Department, Ifakara Health InstituteEnvironmental Health and Ecological Sciences Department, Ifakara Health InstituteEnvironmental Health and Ecological Sciences Department, Ifakara Health InstituteInstitute for Disease Modeling, Bill and Melinda Gates FoundationEnvironmental Health and Ecological Sciences Department, Ifakara Health InstituteDepartment of Vector Biology, Liverpool School of Tropical MedicineAbstract Background Malaria transmission in Africa is facilitated by multiple species of Anopheles mosquitoes. These vectors have different behaviors and vectorial capacities and are affected differently by vector control interventions, such as insecticide-treated nets and indoor residual spraying. This review aimed to assess changes in the contribution of different vector species to malaria transmission in east and southern Africa over 20 years of widespread insecticide-based vector control. Methods We searched PubMed, Global Health, and Web of Science online databases for articles published between January 2000 and April 2023 that provided species-specific sporozoite rates for different malaria vectors in east and southern Africa. We extracted data on study characteristics, biting rates, sporozoite infection proportions, and entomological inoculation rates (EIR). Using EIR data, the proportional contribution of each species to malaria transmission was estimated. Results Studies conducted between 2000 and 2010 identified the Anopheles gambiae complex as the primary malaria vector, while studies conducted from 2011 to 2021 indicated the dominance of Anopheles funestus. From 2000 to 2010, in 57% of sites, An. gambiae demonstrated higher parasite infection prevalence than other Anopheles species. Anopheles gambiae also accounted for over 50% of EIR in 76% of the study sites. Conversely, from 2011 to 2021, An. funestus dominated with higher infection rates than other Anopheles in 58% of sites and a majority EIR contribution in 63% of sites. This trend coincided with a decline in overall EIR and the proportion of sporozoite-infected An. gambiae. The main vectors in the An. gambiae complex in the region were Anopheles arabiensis and An. gambiae sensu stricto (s.s.), while the important member of the An. funestus group was An. funestus s.s. Conclusion The contribution of different vector species in malaria transmission has changed over the past 20 years. As the role of An. gambiae has declined, An. funestus now appears to be dominant in most settings in east and southern Africa. Other secondary vector species may play minor roles in specific localities. To improve malaria control in the region, vector control should be optimized to match these entomological trends, considering the different ecologies and behaviors of the dominant vector species. Graphical Abstracthttps://doi.org/10.1186/s13071-023-06019-1Malaria transmissionEntomological trendsAnophelesEast and southern Africa |
| spellingShingle | Betwel J. Msugupakulya Naomi H. Urio Mohammed Jumanne Halfan S. Ngowo Prashanth Selvaraj Fredros O. Okumu Anne L. Wilson Changes in contributions of different Anopheles vector species to malaria transmission in east and southern Africa from 2000 to 2022 Parasites & Vectors Malaria transmission Entomological trends Anopheles East and southern Africa |
| title | Changes in contributions of different Anopheles vector species to malaria transmission in east and southern Africa from 2000 to 2022 |
| title_full | Changes in contributions of different Anopheles vector species to malaria transmission in east and southern Africa from 2000 to 2022 |
| title_fullStr | Changes in contributions of different Anopheles vector species to malaria transmission in east and southern Africa from 2000 to 2022 |
| title_full_unstemmed | Changes in contributions of different Anopheles vector species to malaria transmission in east and southern Africa from 2000 to 2022 |
| title_short | Changes in contributions of different Anopheles vector species to malaria transmission in east and southern Africa from 2000 to 2022 |
| title_sort | changes in contributions of different anopheles vector species to malaria transmission in east and southern africa from 2000 to 2022 |
| topic | Malaria transmission Entomological trends Anopheles East and southern Africa |
| url | https://doi.org/10.1186/s13071-023-06019-1 |
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