Behavioral responses of pyrethroid resistant and susceptible Anopheles gambiae mosquitoes to insecticide treated bed net

• Published in: PloS one 2022-04, Vol.17 (4), p.e0266420-e0266420
• Main Authors: Machani, Maxwell G, Ochomo, Eric, Amimo, Fred, Mukabana, Wolfgang R, Githeko, Andrew K, Yan, Guiyun, Afrane, Yaw A
• Format: Article
• Language: English
• Subjects: Animals; Anopheles; Anopheles - physiology; Anopheles gambiae; Baiting; Barriers; Behavior; Biology and Life Sciences; Culicidae; Deltamethrin; Disease transmission; Entomology; Experiments; Female; Females; Fluorescence; Health sciences; Host searching behavior; Humans; Huts; Insecticide Resistance; Insecticide-Treated Bednets; Insecticides; Insecticides - pharmacology; Malaria; Malaria - prevention & control; Medical research; Medicine and Health Sciences; Methods; Mortality; Mosquito Control - methods; Mosquito Vectors - physiology; Mosquitoes; Mutation; Netting (materials/structures); Pesticide resistance; Physiology; Population; Prevention; Progeny; Public health; Pyrethrins - pharmacology; Pyrethroids; Social Sciences; Vector-borne diseases; Vectors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0266420

Long-lasting insecticidal nets are an effective tool in reducing malaria transmission. However, with increasing insecticide resistance little is known about how physiologically resistant malaria vectors behave around a human-occupied bed net, despite their importance in malaria transmission. We used the Mbita bednet trap to assess the host-seeking behavior of insecticide-resistant Anopheles gambiae mosquitoes under semi-field conditions. The trap incorporates a mosquito netting panel which acts as a mechanical barrier that prevents host-seeking mosquitoes from reaching the human host baiting the trap. Susceptible and pyrethroid-resistant colonies of female Anopheles gambiae mosquitoes aged 3-5 days old were used in this study. The laboratory-bred mosquitoes were color-marked with fluorescent powders and released inside a semi-field environment where a human subject slept inside a bednet trap erected in a traditional African hut. The netting panel inside the trap was either untreated (control) or deltamethrin-impregnated. The mosquitoes were released outside the hut. Only female mosquitoes were used. A window exit trap was installed on the hut to catch mosquitoes exiting the hut. A prokopack aspirator was used to collect indoor and outdoor resting mosquitoes. In addition, clay pots were placed outside the hut to collect outdoor resting mosquitoes. The F1 progeny of wild-caught mosquitoes were also used in these experiments. The mean number of resistant mosquitoes trapped in the deltamethrin-impregnated bed net trap was higher (mean = 50.21± 3.7) compared to susceptible counterparts (mean + 22.4 ± 1.31) (OR = 1.445; P