Comparative susceptibility to permethrin of two Anopheles gambiae s.l. populations from Southern Benin, regarding mosquito sex, physiological status, and mosquito age

The current study was aimed to investigate on dynamics of propoxur resistance in Anopheles gambiae s.l. populations from N’ dali district in northern Benin (West Africa) and also to investigate on dynamics of malathion resistance in Anopheles gambiae s. l. populations from Toffo district in southern Benin. Larvae and pupae of Anopheles gambiae s. l . mosquitoes were collected from the breeding sites in Borgou and Atlantic departments in 2015 and 2019. WHO susceptibility tests were conducted on unfed female mosquitoes aged 2-5 days old. WHO bioassays were performed with impregnated papers with propoxur 0.1% and with malathion 5%. PCR techniques were used to detect species and Ace-1 mutations in 2015. Anopheles gambiae s. l. populations from N’dali were resistant to propoxur in 2015 and were still remained resistant to this product in 2019. Regarding Anopheles gambiae s. l. populations from Toffo, they were susceptible to malathion in 2015 whereas the malathion resistance status of these mosquitoes requires further investigation in 2019. PCR revealed that all specimens tested were Anopheles gambiae s. s. The presence of Ace-1R at very low frequency (0.01) was observed in Anopheles gambiae s. l. populations from both districts. This study shows that propoxur resistance detected in An. gambiae s. l. populations from N’ dali needs to be monitored for insecticide resistance in this area.

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Human biting rhythm of Anopheles gambiae s.l. and sleeping behaviour of pregnant women in a lagoon area in Southern Benin

10.21203/rs.3.rs-396314/v1 ◽

2021 ◽

Author(s):

Armel DJENONTIN ◽

Aziz BOURAÏMA ◽

Christophe SOARES ◽

Seun EGBINOLA ◽

Gilles COTTRELL

Keyword(s):

Plasmodium Falciparum ◽

Pregnant Women ◽

Anopheles Gambiae ◽

Early Morning ◽

Allelic Frequency ◽

Malaria Vectors ◽

Mosquito Nets ◽

Anopheles Gambiae S.L ◽

Almost All ◽

Southern Benin

Abstract ObjectiveIn the framework of EVALMOUS study aiming to assess the use and effectiveness of mosquito nets by pregnant women and other members of their household in a lagoon area in southern Benin, the behaviour of pregnant women relative to the time they go to bed using the net were recorded. Malaria vectors biting rhythm, Plasmodium falciparum infection and insecticide resistance genes in malaria vectors were also determined.ResultsOverall, 3848 females of Anopheles gambiae s. l. were collected and 280 pregnant women responded to the survey. Almost all Anopheles gambiae s. l. tested were Anopheles coluzzi with the exception of two, which were Anopheles melas. The CSP index in malaria vector was 1.85% and the allelic frequency of kdr gene was 74.4%. Around 90% of bites and Plasmodium falciparum transmission occurred between 10 p.m. and 6 a.m., which coincides with the period when more than 80% of pregnant women were under bednet. Despite a slight early evening and early morning biting activity of malaria vectors in the study area, the good use of nets might remain a useful protection tool against mosquito biting and malaria transmission.

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Dynamics of organophosphate and carbamate resistance in Anopheles gambiae s. l. populations from south and north Benin, West Africa

World Journal of Biology Pharmacy and Health Sciences ◽

10.30574/wjbphs.2021.6.3.0042 ◽

2021 ◽

Vol 6 (3) ◽

pp. 020-026

Author(s):

Nazaire Aïzoun

Keyword(s):

West Africa ◽

Insecticide Resistance ◽

Anopheles Gambiae ◽

Low Frequency ◽

Breeding Sites ◽

Very Low Frequency ◽

Anopheles Gambiae S.L ◽

Susceptibility Tests ◽

Pcr Techniques ◽

Southern Benin

The current study was aimed to investigate on dynamics of propoxur resistance in Anopheles gambiae s.l. populations from N’ dali district in northern Benin (West Africa) and also to investigate on dynamics of malathion resistance in Anopheles gambiae s. l. populations from Toffo district in southern Benin. Larvae and pupae of Anopheles gambiae s. l . mosquitoes were collected from the breeding sites in Borgou and Atlantic departments in 2015 and 2019. WHO susceptibility tests were conducted on unfed female mosquitoes aged 2-5 days old. WHO bioassays were performed with impregnated papers with propoxur 0.1% and with malathion 5%. PCR techniques were used to detect species and Ace-1 mutations in 2015. Anopheles gambiae s. l. populations from N’dali were resistant to propoxur in 2015 and were still remained resistant to this product in 2019. Regarding Anopheles gambiae s. l. populations from Toffo, they were susceptible to malathion in 2015 whereas the malathion resistance status of these mosquitoes requires further investigation in 2019. PCR revealed that all specimens tested were Anopheles gambiae s. s. The presence of Ace-1R at very low frequency (0.01) was observed in Anopheles gambiae s. l. populations from both districts. This study shows that propoxur resistance detected in An. gambiae s. l. populations from N’ dali needs to be monitored for insecticide resistance in this area.

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Using pastoralist community knowledge to locate and treat dry-season mosquito breeding habitats with pyriproxyfen to control Anopheles gambiae s.l. and Anopheles funestus s.l. in rural Tanzania

Parasitology Research ◽

10.1007/s00436-020-07040-4 ◽

2021 ◽

Author(s):

Eliza T. Lupenza ◽

Japhet Kihonda ◽

Alex J. Limwagu ◽

Halfan S. Ngowo ◽

Robert D. Sumaye ◽

...

Keyword(s):

Anopheles Gambiae ◽

Anopheles Funestus ◽

Dry Season ◽

Community Knowledge ◽

Pastoralist Community ◽

Rural Tanzania ◽

Breeding Habitats ◽

Anopheles Gambiae S.L ◽

Mosquito Breeding

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Human biting rhythm of Anopheles gambiae Giles, 1902 (Diptera: Culicidae) and sleeping behaviour of pregnant women in a lagoon area in Southern Benin

BMC Research Notes ◽

10.1186/s13104-021-05615-7 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Armel Djènontin ◽

Aziz Bouraima ◽

Christophe Soares ◽

Seun Egbinola ◽

Gilles Cottrell

Keyword(s):

Plasmodium Falciparum ◽

Pregnant Women ◽

Anopheles Gambiae ◽

Early Morning ◽

Allelic Frequency ◽

Malaria Vectors ◽

Mosquito Nets ◽

Anopheles Gambiae Giles ◽

Almost All ◽

Southern Benin

Abstract Objective In the framework of EVALMOUS study aiming to assess the use and effectiveness of mosquito nets by pregnant women and other members of their household in a lagoon area in southern Benin, the behaviour of pregnant women relative to the time they go to bed using the net were recorded. Malaria vectors biting rhythm, Plasmodium falciparum infection and insecticide resistance genes in malaria vectors were also determined. Results Overall, 3848 females of Anopheles gambiae s. l were collected and 280 pregnant women responded to the survey. Almost all Anopheles gambiae s. l. tested were Anopheles coluzzi Coetzee and Wilkerson 2013 (Diptera: Culicidae). The CSP index in malaria vector was 1.85% and the allelic frequency of kdr gene was 74.4%. Around 90% of bites and Plasmodium falciparum Welch, 1897 (Haemosporida: Plasmodiidae) transmission occurred between 10 p.m. and 6 a.m., which coincides with the period when more than 80% of pregnant women were under bednet. Despite a slight early evening and early morning biting activity of malaria vectors in the study area, the good use of nets might remain a useful protection tool against mosquito biting and malaria transmission.

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Effect of naturally occurring Wolbachia in Anopheles gambiae s.l. mosquitoes from Mali on Plasmodium falciparum malaria transmission

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1716181114 ◽

2017 ◽

Vol 114 (47) ◽

pp. 12566-12571 ◽

Cited By ~ 44

Author(s):

Fabio M. Gomes ◽

Bretta L. Hixson ◽

Miles D. W. Tyner ◽

Jose Luis Ramirez ◽

Gaspar E. Canepa ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Anopheles Gambiae ◽

Malaria Transmission ◽

Deleterious Effect ◽

Plasmodium Falciparum Malaria ◽

Anopheles Coluzzii ◽

Naturally Occurring ◽

Anopheles Gambiae S.L ◽

Cat Fleas ◽

Sporozoite Infection

A naturally occurring Wolbachia strain (wAnga-Mali) was identified in mosquitoes of the Anopheles gambiae complex collected in the Malian villages of Dangassa and Kenieroba. Phylogenetic analysis of the nucleotide sequence of two 16S rRNA regions showed that wAnga-Mali clusters with Wolbachia strains from supergroup A and has the highest homology to a Wolbachia strain isolated from cat fleas (Ctenocephalides). wAnga-Mali is different from two Wolbachia strains previously reported in A. gambiae from Burkina Faso (wAnga_VK5_STP and wAnga_VK5_3.1a). Quantitative analysis of Wolbachia and Plasmodium sporozoite infection in field-collected mosquitoes indicates that the prevalence and intensity of Plasmodium falciparum sporozoite infection is significantly lower in Wolbachia-infected females. The presence of Wolbachia in females from a laboratory Anopheles coluzzii (A. gambiae, M form) colony experimentally infected with P. falciparum (NF54 strain) gametocyte cultures slightly enhanced oocyst infection. However, Wolbachia infection significantly reduced the prevalence and intensity of sporozoite infection, as observed in the field. This indicates that wAnga-Mali infection does not limit early stages of Plasmodium infection in the mosquito, but it has a strong deleterious effect on sporozoites and reduces malaria transmission.

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