دورية أكاديمية
Determination of the discriminating concentration of chlorfenapyr (pyrrole) and Anopheles gambiae sensu lato susceptibility testing in preparation for distribution of Interceptor® G2 insecticide-treated nets
العنوان: | Determination of the discriminating concentration of chlorfenapyr (pyrrole) and Anopheles gambiae sensu lato susceptibility testing in preparation for distribution of Interceptor® G2 insecticide-treated nets |
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المؤلفون: | Richard M. Oxborough, Aklilu Seyoum, Yemane Yihdego, Joseph Chabi, Francis Wat’senga, Fiacre R. Agossa, Sylvester Coleman, Samdi Lazarus Musa, Ousmane Faye, Michael Okia, Mohamed Bayoh, Evelyne Alyko, Jean-Desire Rakotoson, Hieronymo Masendu, Arthur Sovi, Libasse Gadiaga, Bernard Abong’o, Kevin Opondo, Ibrahima Baber, Roch Dabire, Virgile Gnanguenon, Gedeon Yohannes, Kenyssony Varela, Etienne Fondjo, Jenny Carlson, Jennifer S. Armistead, Dereje Dengela |
المصدر: | Malaria Journal, Vol 20, Iss 1, Pp 1-10 (2021) |
بيانات النشر: | BMC, 2021. |
سنة النشر: | 2021 |
المجموعة: | LCC:Arctic medicine. Tropical medicine LCC:Infectious and parasitic diseases |
مصطلحات موضوعية: | Chlorfenapyr, Pyrrole, Anopheles gambiae, Interceptor G2, CDC bottle bioassay, Discriminating concentration, Arctic medicine. Tropical medicine, RC955-962, Infectious and parasitic diseases, RC109-216 |
الوصف: | Abstract Background Following agricultural use and large-scale distribution of insecticide-treated nets (ITNs), malaria vector resistance to pyrethroids is widespread in sub-Saharan Africa. Interceptor® G2 is a new dual active ingredient (AI) ITN treated with alpha-cypermethrin and chlorfenapyr for the control of pyrethroid-resistant malaria vectors. In anticipation of these new nets being more widely distributed, testing was conducted to develop a chlorfenapyr susceptibility bioassay protocol and gather susceptibility information. Methods Bottle bioassay tests were conducted using five concentrations of chlorfenapyr at 12.5, 25, 50, 100, and 200 µg AI/bottle in 10 countries in sub-Saharan Africa using 13,639 wild-collected Anopheles gambiae sensu lato (s.l.) (56 vector populations per dose) and 4,494 pyrethroid-susceptible insectary mosquitoes from 8 colonized strains. In parallel, susceptibility tests were conducted using a provisional discriminating concentration of 100 µg AI/bottle in 16 countries using 23,422 wild-collected, pyrethroid-resistant An. gambiae s.l. (259 vector populations). Exposure time was 60 min, with mortality recorded at 24, 48 and 72 h after exposure. Results Median mortality rates (up to 72 h after exposure) of insectary colony mosquitoes was 100% at all five concentrations tested, but the lowest dose to kill all mosquitoes tested was 50 µg AI/bottle. The median 72-h mortality of wild An. gambiae s.l. in 10 countries was 71.5, 90.5, 96.5, 100, and 100% at concentrations of 12.5, 25, 50, 100, and 200 µg AI/bottle, respectively. Log-probit analysis of the five concentrations tested determined that the LC95 of wild An. gambiae s.l. was 67.9 µg AI/bottle (95% CI: 48.8–119.5). The discriminating concentration of 203.8 µg AI/bottle (95% CI: 146–359) was calculated by multiplying the LC95 by three. However, the difference in mortality between 100 and 200 µg AI/bottle was minimal and large-scale testing using 100 µg AI/bottle with wild An. gambiae s.l. in 16 countries showed that this concentration was generally suitable, with a median mortality rate of 100% at 72 h. Conclusions This study determined that 100 or 200 µg AI/bottle chlorfenapyr in bottle bioassays are suitable discriminating concentrations for monitoring susceptibility of wild An. gambiae s.l., using mortality recorded up to 72 h. Testing in 16 countries in sub-Saharan Africa demonstrated vector susceptibility to chlorfenapyr, including mosquitoes with multiple resistance mechanisms to pyrethroids. |
نوع الوثيقة: | article |
وصف الملف: | electronic resource |
اللغة: | English |
تدمد: | 1475-2875 |
Relation: | https://doaj.org/toc/1475-2875 |
DOI: | 10.1186/s12936-021-03847-3 |
URL الوصول: | https://doaj.org/article/178891234e0b44b0a55d29c0a9e364d6 |
رقم الأكسشن: | edsdoj.178891234e0b44b0a55d29c0a9e364d6 |
قاعدة البيانات: | Directory of Open Access Journals |
تدمد: | 14752875 |
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DOI: | 10.1186/s12936-021-03847-3 |