Persistently high proportions of plasmodium-infected Anopheles funestus mosquitoes in two villages in the Kilombero valley, South-Eastern Tanzania
Background: In south-eastern Tanzania where insecticide-treated nets have been widely used for >20 years, malaria transmission has greatly reduced but remains highly heterogenous over small distances. This study investigated the seasonal prevalence of Plasmodium sporozoite infections in the two m...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-08-01
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| Series: | Parasite Epidemiology and Control |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2405673122000289 |
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| author | Salum A. Mapua Emmanuel E. Hape Japhet Kihonda Hamis Bwanary Khamis Kifungo Masoud Kilalangongono Emmanuel W. Kaindoa Halfan S. Ngowo Fredros O. Okumu |
| author_facet | Salum A. Mapua Emmanuel E. Hape Japhet Kihonda Hamis Bwanary Khamis Kifungo Masoud Kilalangongono Emmanuel W. Kaindoa Halfan S. Ngowo Fredros O. Okumu |
| author_sort | Salum A. Mapua |
| collection | DOAJ |
| description | Background: In south-eastern Tanzania where insecticide-treated nets have been widely used for >20 years, malaria transmission has greatly reduced but remains highly heterogenous over small distances. This study investigated the seasonal prevalence of Plasmodium sporozoite infections in the two main malaria vector species, Anopheles funestus and Anopheles arabiensis for 34 months, starting January 2018 to November 2020. Methods: Adult mosquitoes were collected using CDC-light traps and Prokopack aspirators inside local houses in Igumbiro and Sululu villages, where earlier surveys had found very high densities of An. funestus. Collected females were sorted by taxa, and the samples examined using ELISA assays for detecting Plasmodium circumsporozoite protein in their salivary glands. Results: Of 7859 An. funestus tested, 4.6% (n = 365) were positive for Pf sporozoites in the salivary glands. On the contrary, only 0.4% (n = 9) of the 2382 An. arabiensis tested were positive. The sporozoite prevalence did not vary significantly between the villages or seasons. Similarly, the proportions of parous females of either species were not significantly different between the two villages (p > 0.05) but was slightly higher in An. funestus (0.50) than in An. arabiensis (0.42). Analysis of the 2020 data determined that An. funestus contributed 97.7% of all malaria transmitted in households in these two villages. Conclusions: In contexts where individual vector species mediate most of the pathogen transmission, it may be most appropriate to pursue a species-focused approach to better understand the ecology of the dominant vectors and target them with effective interventions to suppress transmission. Despite the ongoing efforts on tackling malaria in the two study villages, there is still persistently high Plasmodium infection prevalence in local populations of An. funestus, which now carry ~97% of all malaria infections and mediates intense year-round transmission. Further reduction in malaria burden in these or other similar settings requires effective targeting of An. funestus. |
| first_indexed | 2024-04-14T02:53:36Z |
| format | Article |
| id | doaj.art-63dcc42488bf4803972b86b6e6ad8bf9 |
| institution | Directory Open Access Journal |
| issn | 2405-6731 |
| language | English |
| last_indexed | 2024-04-14T02:53:36Z |
| publishDate | 2022-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Parasite Epidemiology and Control |
| spelling | doaj.art-63dcc42488bf4803972b86b6e6ad8bf92022-12-22T02:16:12ZengElsevierParasite Epidemiology and Control2405-67312022-08-0118e00264Persistently high proportions of plasmodium-infected Anopheles funestus mosquitoes in two villages in the Kilombero valley, South-Eastern TanzaniaSalum A. Mapua0Emmanuel E. Hape1Japhet Kihonda2Hamis Bwanary3Khamis Kifungo4Masoud Kilalangongono5Emmanuel W. Kaindoa6Halfan S. Ngowo7Fredros O. Okumu8Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, Tanzania; Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Huxley Building, Keele, Staffordshire ST5 5BG, UK; Corresponding author at: Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, Tanzania.Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, Tanzania; Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UKEnvironmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, TanzaniaEnvironmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, TanzaniaEnvironmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, TanzaniaEnvironmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, TanzaniaEnvironmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, Tanzania; School of Life Science and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, TanzaniaEnvironmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, Tanzania; Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UKEnvironmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Morogoro, Tanzania; School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK; School of Life Science and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, TanzaniaBackground: In south-eastern Tanzania where insecticide-treated nets have been widely used for >20 years, malaria transmission has greatly reduced but remains highly heterogenous over small distances. This study investigated the seasonal prevalence of Plasmodium sporozoite infections in the two main malaria vector species, Anopheles funestus and Anopheles arabiensis for 34 months, starting January 2018 to November 2020. Methods: Adult mosquitoes were collected using CDC-light traps and Prokopack aspirators inside local houses in Igumbiro and Sululu villages, where earlier surveys had found very high densities of An. funestus. Collected females were sorted by taxa, and the samples examined using ELISA assays for detecting Plasmodium circumsporozoite protein in their salivary glands. Results: Of 7859 An. funestus tested, 4.6% (n = 365) were positive for Pf sporozoites in the salivary glands. On the contrary, only 0.4% (n = 9) of the 2382 An. arabiensis tested were positive. The sporozoite prevalence did not vary significantly between the villages or seasons. Similarly, the proportions of parous females of either species were not significantly different between the two villages (p > 0.05) but was slightly higher in An. funestus (0.50) than in An. arabiensis (0.42). Analysis of the 2020 data determined that An. funestus contributed 97.7% of all malaria transmitted in households in these two villages. Conclusions: In contexts where individual vector species mediate most of the pathogen transmission, it may be most appropriate to pursue a species-focused approach to better understand the ecology of the dominant vectors and target them with effective interventions to suppress transmission. Despite the ongoing efforts on tackling malaria in the two study villages, there is still persistently high Plasmodium infection prevalence in local populations of An. funestus, which now carry ~97% of all malaria infections and mediates intense year-round transmission. Further reduction in malaria burden in these or other similar settings requires effective targeting of An. funestus.http://www.sciencedirect.com/science/article/pii/S2405673122000289Anopheles funestusKilombero valleyMalaria transmissionPlasmodiumSporozoite prevalenceIfakara health institute |
| spellingShingle | Salum A. Mapua Emmanuel E. Hape Japhet Kihonda Hamis Bwanary Khamis Kifungo Masoud Kilalangongono Emmanuel W. Kaindoa Halfan S. Ngowo Fredros O. Okumu Persistently high proportions of plasmodium-infected Anopheles funestus mosquitoes in two villages in the Kilombero valley, South-Eastern Tanzania Parasite Epidemiology and Control Anopheles funestus Kilombero valley Malaria transmission Plasmodium Sporozoite prevalence Ifakara health institute |
| title | Persistently high proportions of plasmodium-infected Anopheles funestus mosquitoes in two villages in the Kilombero valley, South-Eastern Tanzania |
| title_full | Persistently high proportions of plasmodium-infected Anopheles funestus mosquitoes in two villages in the Kilombero valley, South-Eastern Tanzania |
| title_fullStr | Persistently high proportions of plasmodium-infected Anopheles funestus mosquitoes in two villages in the Kilombero valley, South-Eastern Tanzania |
| title_full_unstemmed | Persistently high proportions of plasmodium-infected Anopheles funestus mosquitoes in two villages in the Kilombero valley, South-Eastern Tanzania |
| title_short | Persistently high proportions of plasmodium-infected Anopheles funestus mosquitoes in two villages in the Kilombero valley, South-Eastern Tanzania |
| title_sort | persistently high proportions of plasmodium infected anopheles funestus mosquitoes in two villages in the kilombero valley south eastern tanzania |
| topic | Anopheles funestus Kilombero valley Malaria transmission Plasmodium Sporozoite prevalence Ifakara health institute |
| url | http://www.sciencedirect.com/science/article/pii/S2405673122000289 |
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