Comparative assessment of insecticide resistance phenotypes in two major malaria vectors, Anopheles funestus and Anopheles arabiensis in south-eastern Tanzania
Abstract Background Long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) have greatly reduced malaria transmission in sub-Saharan Africa, but are threatened by insecticide resistance. In south-eastern Tanzania, pyrethroid-resistant Anopheles funestus are now implicated in...
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ftdoajarticles:oai:doaj.org/article:788f6e5722044d968aee9cc9c348e317 2023-05-15T15:16:10+02:00 Comparative assessment of insecticide resistance phenotypes in two major malaria vectors, Anopheles funestus and Anopheles arabiensis in south-eastern Tanzania Polius G. Pinda Claudia Eichenberger Halfan S. Ngowo Dickson S. Msaky Said Abbasi Japhet Kihonda Hamis Bwanaly Fredros O. Okumu 2020-11-01T00:00:00Z https://doi.org/10.1186/s12936-020-03483-3 https://doaj.org/article/788f6e5722044d968aee9cc9c348e317 EN eng BMC http://link.springer.com/article/10.1186/s12936-020-03483-3 https://doaj.org/toc/1475-2875 doi:10.1186/s12936-020-03483-3 1475-2875 https://doaj.org/article/788f6e5722044d968aee9cc9c348e317 Malaria Journal, Vol 19, Iss 1, Pp 1-11 (2020) Insecticide resistance Anopheles funestus PBO Ifakara health institute Tanzania Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 article 2020 ftdoajarticles https://doi.org/10.1186/s12936-020-03483-3 2022-12-31T03:48:12Z Abstract Background Long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) have greatly reduced malaria transmission in sub-Saharan Africa, but are threatened by insecticide resistance. In south-eastern Tanzania, pyrethroid-resistant Anopheles funestus are now implicated in > 80% of malaria infections, even in villages where the species occurs at lower densities than the other vector, Anopheles arabiensis. This study compared the insecticide resistance phenotypes between the two malaria vectors in an area where pyrethroid-LLINs are widely used. Methods The study used the World Health Organization (WHO) assays with 1×, 5× and 10× insecticide doses to assess levels of resistance, followed by synergist bioassays to understand possible mechanisms of the observed resistance phenotypes. The tests involved adult mosquitoes collected from three villages across two districts in south-eastern Tanzania and included four insecticide classes. Findings At baseline doses (1×), both species were resistant to the two candidate pyrethroids (permethrin and deltamethrin), but susceptible to the organophosphate (pirimiphos-methyl). Anopheles funestus, but not An. arabiensis was also resistant to the carbamate (bendiocarb). Both species were resistant to DDT in all villages except in one village where An. arabiensis was susceptible. Anopheles funestus showed strong resistance to pyrethroids, surviving the 5× and 10× doses, while An. arabiensis reverted to susceptibility at the 5× dose. Pre-exposure to the synergist, piperonyl butoxide (PBO), enhanced the potency of the pyrethroids against both species and resulted in full susceptibility of An. arabiensis (> 98% mortality). However, for An. funestus from two villages, permethrin-associated mortalities after pre-exposure to PBO only exceeded 90% but not 98%. Conclusions In south-eastern Tanzania, where An. funestus dominates malaria transmission, the species also has much stronger resistance to pyrethroids than its counterpart, An. arabiensis, and can ... Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Malaria Journal 19 1 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
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English |
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Insecticide resistance Anopheles funestus PBO Ifakara health institute Tanzania Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
spellingShingle |
Insecticide resistance Anopheles funestus PBO Ifakara health institute Tanzania Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 Polius G. Pinda Claudia Eichenberger Halfan S. Ngowo Dickson S. Msaky Said Abbasi Japhet Kihonda Hamis Bwanaly Fredros O. Okumu Comparative assessment of insecticide resistance phenotypes in two major malaria vectors, Anopheles funestus and Anopheles arabiensis in south-eastern Tanzania |
topic_facet |
Insecticide resistance Anopheles funestus PBO Ifakara health institute Tanzania Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
description |
Abstract Background Long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) have greatly reduced malaria transmission in sub-Saharan Africa, but are threatened by insecticide resistance. In south-eastern Tanzania, pyrethroid-resistant Anopheles funestus are now implicated in > 80% of malaria infections, even in villages where the species occurs at lower densities than the other vector, Anopheles arabiensis. This study compared the insecticide resistance phenotypes between the two malaria vectors in an area where pyrethroid-LLINs are widely used. Methods The study used the World Health Organization (WHO) assays with 1×, 5× and 10× insecticide doses to assess levels of resistance, followed by synergist bioassays to understand possible mechanisms of the observed resistance phenotypes. The tests involved adult mosquitoes collected from three villages across two districts in south-eastern Tanzania and included four insecticide classes. Findings At baseline doses (1×), both species were resistant to the two candidate pyrethroids (permethrin and deltamethrin), but susceptible to the organophosphate (pirimiphos-methyl). Anopheles funestus, but not An. arabiensis was also resistant to the carbamate (bendiocarb). Both species were resistant to DDT in all villages except in one village where An. arabiensis was susceptible. Anopheles funestus showed strong resistance to pyrethroids, surviving the 5× and 10× doses, while An. arabiensis reverted to susceptibility at the 5× dose. Pre-exposure to the synergist, piperonyl butoxide (PBO), enhanced the potency of the pyrethroids against both species and resulted in full susceptibility of An. arabiensis (> 98% mortality). However, for An. funestus from two villages, permethrin-associated mortalities after pre-exposure to PBO only exceeded 90% but not 98%. Conclusions In south-eastern Tanzania, where An. funestus dominates malaria transmission, the species also has much stronger resistance to pyrethroids than its counterpart, An. arabiensis, and can ... |
format |
Article in Journal/Newspaper |
author |
Polius G. Pinda Claudia Eichenberger Halfan S. Ngowo Dickson S. Msaky Said Abbasi Japhet Kihonda Hamis Bwanaly Fredros O. Okumu |
author_facet |
Polius G. Pinda Claudia Eichenberger Halfan S. Ngowo Dickson S. Msaky Said Abbasi Japhet Kihonda Hamis Bwanaly Fredros O. Okumu |
author_sort |
Polius G. Pinda |
title |
Comparative assessment of insecticide resistance phenotypes in two major malaria vectors, Anopheles funestus and Anopheles arabiensis in south-eastern Tanzania |
title_short |
Comparative assessment of insecticide resistance phenotypes in two major malaria vectors, Anopheles funestus and Anopheles arabiensis in south-eastern Tanzania |
title_full |
Comparative assessment of insecticide resistance phenotypes in two major malaria vectors, Anopheles funestus and Anopheles arabiensis in south-eastern Tanzania |
title_fullStr |
Comparative assessment of insecticide resistance phenotypes in two major malaria vectors, Anopheles funestus and Anopheles arabiensis in south-eastern Tanzania |
title_full_unstemmed |
Comparative assessment of insecticide resistance phenotypes in two major malaria vectors, Anopheles funestus and Anopheles arabiensis in south-eastern Tanzania |
title_sort |
comparative assessment of insecticide resistance phenotypes in two major malaria vectors, anopheles funestus and anopheles arabiensis in south-eastern tanzania |
publisher |
BMC |
publishDate |
2020 |
url |
https://doi.org/10.1186/s12936-020-03483-3 https://doaj.org/article/788f6e5722044d968aee9cc9c348e317 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Malaria Journal, Vol 19, Iss 1, Pp 1-11 (2020) |
op_relation |
http://link.springer.com/article/10.1186/s12936-020-03483-3 https://doaj.org/toc/1475-2875 doi:10.1186/s12936-020-03483-3 1475-2875 https://doaj.org/article/788f6e5722044d968aee9cc9c348e317 |
op_doi |
https://doi.org/10.1186/s12936-020-03483-3 |
container_title |
Malaria Journal |
container_volume |
19 |
container_issue |
1 |
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1766346458062127104 |