Mosquitoes fauna diversity, Plasmodium falciparum infection and insecticide resistance status in malaria vectors in a lagoon area in Southern Benin, West Africa

Lagoon areas maintain ideal water conditions for mosquito breeding habitats and are thus environments with high risk of malaria transmission. In Benin, several administrative units, among which the Sô-Ava District, are located in lagoon areas. We conducted entomological surveys in this lagoon district from July 2014 to June 2015, in order to update existing information on biodiversity of mosquitoes, Plasmodium falciparum infection, and insecticide resistance status in malaria vectors. Our survey found that Culex quinquefasciatus and Mansonia africana were the most abundant species, and that Anopheles coluzzii represented the main malaria vector in this area, followed by Anopheles melas. Only Anopheles coluzzii was positive to Plasmudium falcimarum circum sporozoitic protein (4.2 %). An. gambiae s.l. were susceptible to chlorpyrifos-methyl and bendiocarb but resistant to all pyrethroids tested and to pyrimiphos-methyl. The average of kdr allelic frequency from July 2014 to June 2015 was 77.4% and that of ace1 gene was less than 1%. We conclude that Anopheles coluzzii is the main malaria vector in the lagoon area we studied, somewhat contrary to our expectations. However, this malaria vector was resistant to insecticides used for bed net impregnation, even if the resistance level was lower than observed in other parts of Benin.

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Studying fitness cost of Plasmodium falciparum infection in malaria vectors: validation of an appropriate negative control

Malaria Journal ◽

10.1186/1475-2875-12-2 ◽

2013 ◽

Vol 12 (1) ◽

pp. 2 ◽

Cited By ~ 23

Author(s):

Ibrahim Sangare ◽

Yannis Michalakis ◽

Bienvenue Yameogo ◽

Roch Dabire ◽

Isabelle Morlais ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Negative Control ◽

Falciparum Infection ◽

Fitness Cost ◽

Malaria Vectors ◽

Plasmodium Falciparum Infection

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Social Acceptability and Durability of Two Different House Screening Interventions against Exposure to Malaria Vectors, Plasmodium falciparum Infection, and Anemia in Children in The Gambia, West Africa

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.2010.10-0311 ◽

2010 ◽

Vol 83 (5) ◽

pp. 965-972 ◽

Cited By ~ 17

Author(s):

Matthew J. Kirby ◽

Ann H. Kelly ◽

Momodou Jasseh ◽

Steve W. Lindsay ◽

Caroline O. H. Jones ◽

...

Keyword(s):

Plasmodium Falciparum ◽

West Africa ◽

Falciparum Infection ◽

The Gambia ◽

Malaria Vectors ◽

Social Acceptability ◽

Plasmodium Falciparum Infection

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Inhibition of JNK signaling in the Asian malaria vector Anopheles stephensi extends mosquito longevity and improves resistance to Plasmodium falciparum infection

PLoS Pathogens ◽

10.1371/journal.ppat.1007418 ◽

2018 ◽

Vol 14 (11) ◽

pp. e1007418 ◽

Cited By ~ 9

Author(s):

Lattha Souvannaseng ◽

Lewis Vibul Hun ◽

Heather Baker ◽

John M. Klyver ◽

Bo Wang ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Malaria Vector ◽

Anopheles Stephensi ◽

Falciparum Infection ◽

Jnk Signaling ◽

Plasmodium Falciparum Infection

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Risk factors associated with house entry of malaria vectors in an area of Burkina Faso with high, persistent malaria transmission and high insecticide resistance

Malaria Journal ◽

10.1186/s12936-021-03926-5 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Jean Baptiste Yaro ◽

Alfred B. Tiono ◽

Antoine Sanou ◽

Hyacinthe K. Toe ◽

John Bradley ◽

...

Keyword(s):

Risk Factors ◽

Insecticide Resistance ◽

Burkina Faso ◽

Malaria Transmission ◽

Malaria Vector ◽

Malaria Vectors ◽

Anopheles Coluzzii ◽

Mixed Effect ◽

Factors Associated ◽

House Construction

Abstract Background In rural Burkina Faso, the primary malaria vector Anopheles gambiae sensu lato (s.l.) primarily feeds indoors at night. Identification of factors which influence mosquito house entry could lead to development of novel malaria vector control interventions. A study was therefore carried out to identify risk factors associated with house entry of An. gambiae s.l. in south-west Burkina Faso, an area of high insecticide resistance. Methods Mosquitoes were sampled monthly during the malaria transmission season using CDC light traps in 252 houses from 10 villages, each house sleeping at least one child aged five to 15 years old. Potential risk factors for house entry of An. gambiae s.l. were measured, including socio-economic status, caregiver’s education and occupation, number of people sleeping in the same part of the house as the child, use of anti-mosquito measures, house construction and fittings, proximity of anopheline aquatic habitats and presence of animals near the house. Mosquito counts were compared using a generalized linear mixed-effect model with negative binomial and log link function, adjusting for repeated collections. Results 20,929 mosquitoes were caught, of which 16,270 (77.7%) were An. gambiae s.l. Of the 6691 An. gambiae s.l. identified to species, 4101 (61.3%) were An. gambiae sensu stricto and 2590 (38.7%) Anopheles coluzzii. Having a metal-roof on the child’s sleeping space (IRR = 0.55, 95% CI 0.32–0.95, p = 0.03) was associated with fewer malaria vectors inside the home. Conclusion This study demonstrated that the rate of An. gambiae s.l. was 45% lower in sleeping spaces with a metal roof, compared to those with thatch roofs. Improvements in house construction, including installation of metal roofs, should be considered in endemic areas of Africa to reduce the burden of malaria.

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A mating-induced reproductive gene promotes Anopheles tolerance to Plasmodium falciparum infection

PLoS Pathogens ◽

10.1371/journal.ppat.1008908 ◽

2020 ◽

Vol 16 (12) ◽

pp. e1008908

Author(s):

Perrine Marcenac ◽

W. Robert Shaw ◽

Evdoxia G. Kakani ◽

Sara N. Mitchell ◽

Adam South ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Anopheles Stephensi ◽

Steroid Hormone ◽

Field Studies ◽

Falciparum Infection ◽

Malaria Vectors ◽

Parasite Development ◽

Anopheles Coluzzii ◽

Fitness Costs ◽

Mating Status

Anopheles mosquitoes have transmitted Plasmodium parasites for millions of years, yet it remains unclear whether they suffer fitness costs to infection. Here we report that the fecundity of virgin and mated females of two important vectors—Anopheles gambiae and Anopheles stephensi—is not affected by infection with Plasmodium falciparum, demonstrating that these human malaria parasites do not inflict this reproductive cost on their natural mosquito hosts. Additionally, parasite development is not impacted by mating status. However, in field studies using different P. falciparum isolates in Anopheles coluzzii, we find that Mating-Induced Stimulator of Oogenesis (MISO), a female reproductive gene strongly induced after mating by the sexual transfer of the steroid hormone 20-hydroxyecdysone (20E), protects females from incurring fecundity costs to infection. MISO-silenced females produce fewer eggs as they become increasingly infected with P. falciparum, while parasite development is not impacted by this gene silencing. Interestingly, previous work had shown that sexual transfer of 20E has specifically evolved in Cellia species of the Anopheles genus, driving the co-adaptation of MISO. Our data therefore suggest that evolution of male-female sexual interactions may have promoted Anopheles tolerance to P. falciparum infection in the Cellia subgenus, which comprises the most important malaria vectors.

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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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