6 results on '"Aïkpon, Rock"'
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2. Bio-efficacy of Olyset®Plus, PermaNet®3.0 and Interceptor®G2 on pyrethroid-resistant populations of Anopheles gambiaes.l. prior to the June 2023 net distribution campaign in Benin, West Africa
- Author
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Zoungbédji, David Mahouton, Padonou, Germain Gil, Sovi, Arthur, Konkon, Alphonse Keller, Salako, Albert Sourou, Azondékon, Roseric, Sidick, Aboubakar, Ahouandjinou, Juvénal Minassou, Towakinou, Linda, Ossè, Razaki, Aïkpon, Rock, Affoukou, Cyriaque, Baba-Moussa, Lamine, and Akogbéto, Martin
- Abstract
Background: This study investigates the effectiveness of new-generation mosquito nets, like Olyset
® Plus and PermaNet® 3.0, and dual-action nets such as Interceptor® G2, against pyrethroid-resistant Anopheles gambiaemosquitoes following the 2023 mass distribution of long-lasting insecticidal nets in Benin. Methods: We tested wild mosquito populations from six communes in Benin against various pyrethroid (permethrin 0.75%, alphacypermethrin 0.05%, and deltamethrin 0.05%) using WHO tube tests. Additionally, we exposed mosquitoes to chlorfenapyr 100 µg/ml using the CDC bottle bioassay method. A subset of mosquitoes underwent biochemical and PCR tests to check the overexpression of metabolic enzymes and the Kdr L1014F mutation. We evaluated the effectiveness of Olyset® Plus, PermaNet® 3.0, and Interceptor® G2 nets using cone and tunnel tests on both laboratory and field populations of An. gambiae. Results: Overall, the highest mortality rate was 60% with pyrethroid and 98 to100% with chlorfenapyr. In cone tests, all three types of nets induced mortality rates above 80% in the susceptible laboratory strain of An. gambiae. Notably, Olyset® Plus showed the highest mortality rates for pyrethroid-resistant mosquitoes in cone tests, ranging from 81.03% (95% CI: 68.59–90.13) in Djougou to 96.08% (95% CI: 86.54–99.52) in Akpro-Missérété. PermaNet® 3.0 had variable rates, from 42.5% (95% CI: 27.04–59.11) in Djougou to 58.54% (95% CI: 42.11–73.68) in Porto-Novo. However, revealed good results for Interceptor® G2, with 94% (95% CI: 87.40–97.77) mortality and 89.09% blood sampling inhibition in local populations of An. gambiae. In comparison, Interceptor® had lower rates of 17% (95% CI: 10.23–25.82) and 60%, respectively. Conclusion: These results suggest that tunnel tests are effective for evaluating dual-active ingredient nets. Additionally, Interceptor® G2 and PBO nets like Olyset® Plus could be considered as alternatives against pyrethroid-resistant mosquitoes.- Published
- 2024
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3. Insecticide resistance status of Aedes aegyptiand Aedes albopictusmosquitoes in southern Benin, West Africa
- Author
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Konkon, Alphonse Keller, Padonou, Germain Gil, Osse, Razaki, Salako, Albert Sourou, Zoungbédji, David Mahouton, Sina, Haziz, Sovi, Arthur, Tokponnon, Filemon, Aïkpon, Rock, Noukpo, Herbert, Baba-Moussa, Lamine, and Akogbéto, Martin Codjo
- Abstract
Background: The emergence of insecticide resistance in Aedesmosquitoes could undermine efforts to control arboviruses. The present study aims to assess in some communes of Southern Benin, the susceptibility level of Aedes aegypti(Linnaeus, 1762) and Aedes albopictus (Skuse, 1894) to insecticides commonly used in public health, as well as mechanisms involved. Methods: Females Ae. albopictusand Ae. aegypticollected in Ifangni, Porto-Novo, Avrankou, Adjarra and Kétou from June 2021 to October 2022, were exposed to: deltamethrin 0.05%, permethrin 0.75%, alpha-cypermethrin 0.05%, pirimiphos methyl 0.25% and bendiocarb 0.1%, following the standard WHO susceptibility tube test protocol. In some sites, pre-exposure to the synergist PBO was used to verify if pyrethroid resistance of populations of Aedeswas mediated by oxidases. Results: Full susceptibility to deltamethrin and permethrin was observed in all tested populations of Ae. albopictus. However, with alphacypermethrin, a suspected resistance was observed in Adjarra (94.67%), Ifangni (93%) and Porto-Novo (94%), and a resistance in Avrankou (83%). The PBO-alphacypermethrin tests performed, led to a full susceptibility (100%) in all four sites, which confirms the full involvement of oxidases in resistance of all tested populations of Ae. albopictusto alphacypermethrin. At the opposite, Aedes aegyptiwas either resistant or suspected of being resistant to all tested pyrethroids in all four sites, except in Ifangni where a full susceptibility to alphacypermethrin was observed. The full susceptibility of Ae. aegyptito bendiocarb and pirimiphos-methyl in all communes suggests that these two insecticides can be good candidates for an effective control of pyrethroid-resistant Aedesvector populations. Use of permethrin and deltamethrin could also be considered for controlling populations of Ae. albopictus. Conclusion: Results of the present study will help guide strategy to implement for an effective control of Aedesvector populations in Benin.
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- 2023
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4. Study of the efficacy of a Wheaton coated bottle with permethrin and deltamethrin in laboratory conditions and a WHO impregnated paper with bendiocarb in field conditions.
- Author
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Aïzoun, Nazaire, Azondekon, Roseric, Aïkpon, Rock, Gnanguenon, Virgile, Osse, Razaki, Asidi, Alex, and Akogbéto, Martin
- Subjects
PERMETHRIN ,DELTAMETHRIN ,LABORATORIES ,INSECTICIDES ,MICROBIAL sensitivity tests - Abstract
Objective To determine the efficacy of WHO impregnated paper and CDC coated bottle based on number of storage days and number of times of consecutive use, in the assessment of insecticide vector susceptibility tests in laboratory and field conditions. Methods Larvae and pupae of Anopheles gambiae s.l. mosquitoes were collected from the breeding sites in Seme-Kpodji and Cotonou districts in Southern Benin in April 2013 during the first rainy season. Anopheles gambiae s.l. mosquitoes were also collected from the breeding sites in Parakou district in Northern Benin in May 2013 at the beginning of the rainy season. Susceptibility tests were done using impregnated paper with bendiocarb (0.1%) following WHO protocol and stock solutions of permethrin (21.5 μg per bottle) and deltamethrin (12.5 μg per bottle) following CDC protocol on unfed female mosquitoes aged 2-5 days old. These bioassays were repeated a certain number of times. The temperature and relative humidity were monitored and recorded during the susceptibility tests. Results This study showed that a WHO impregnated paper with bendiocarb could be used four times during four consecutive days in field conditions. Regarding a Wheaton coated bottle with permethrin or deltamethrin, they could be used at least three times during four consecutive days in laboratory conditions. Conclusions The day storage and the number of times that a WHO impregnated paper and a CDC coated bottle maintained their efficacy are useful in the assessment of insecticide vectors susceptibility tests. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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5. Comparative susceptibility to permethrin of two Anopheles gambiae s.l. populations from Southern Benin, regarding mosquito sex, physiological status, and mosquito age.
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Aïzoun, Nazaire, Aïkpon, Rock, Azondekon, Roseric, Asidi, Alex, and Akogbéto, Martin
- Subjects
ANOPHELES gambiae ,PERMETHRIN ,MALARIOTHERAPY ,PLASMODIUM - Abstract
Objective To investigate what kind of mosquito sample is necessary for the determination of insecticide susceptibility in malaria vectors. Methods Larvae and pupae of Anopheles gambiae s.l. (An. gambiae) mosquitoes were collected from the breeding sites in Littoral and Oueme departments. The Centers for Disease Control and Prevention (CDC) susceptibility tests were conducted on unfed male and female mosquitoes aged 2-5 days old. CDC susceptibility tests were also conducted on unfed, blood fed and gravid female mosquitoes aged 2-5 days old. These susceptibility tests were also conducted on unfed and blood fed female mosquitoes aged 2-5 days old and 20 days old. CDC biochemical assay using synergist was also carried out to detect any increase in the activity of enzyme typically involved in insecticide metabolism. Results Female An. gambiae Ladji and Sekandji populations were more susceptible than the males when they were unfed and aged 2-5 days old. The mortality rates of blood fed female An. gambiae Ladji and Sekandji populations aged 2-5 days old were lower than those obtained when females were unfed. In addition, the mortality rates of gravid female An. gambiae Ladji and Sekandji populations aged 2-5 days old were lower than those obtained when they were unfed. The mortality rate obtained when female An. gambiae Sekandji populations were unfed and aged 20 days old was higher than the one obtained when these populations were unfed and aged 2-5 days old. The results obtained after effects of synergist penicillin in beeswax on F1 progeny of An. gambiae Ladji populations resistant to permethrin showed that mono-oxygenases were involved in permethrin resistant F1 progeny from Ladji. Conclusions The resistance is a hereditary and dynamic phenomenon which can be due to metabolic mechanisms like overproduction of detoxifying enzymes activity. Many factors influence vector susceptibility to insecticide. Among these factors, there are mosquito sex, mosquito age, its physiological status. Therefore, it is useful to respect the World Health Organization criteria in the assessment of insecticide susceptibility tests in malaria vectors. Otherwise, susceptibility testing is conducted using unfed female mosquitoes aged 3-5 days old. Tests should also be carried out at (25±2) °C and (80±10)% relative humidity. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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6. Evidence of increasing L1014F kdr mutation frequency in Anopheles gambiae s.l. pyrethroid resistant following a nationwide distribution of LLINs by the Beninese National Malaria Control Programme.
- Author
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Aïzoun, Nazaire, Aïkpon, Rock, and Akogbéto, Martin
- Subjects
GENETIC mutation ,ANOPHELES gambiae ,PYRETHROIDS ,MALARIA prevention ,DISEASE susceptibility ,COMPARATIVE studies ,INSECTICIDE analysis - Abstract
Objective To determine the susceptibility status to pyrethroid in Anopheles gambiae s.l. ( An. gambiae ), the distribution of kdr “Leu-Phe” mutation in malaria vectors in Benin and to compare the current frequency of kdr “Leu-Phe” mutation to the previous frequency after long-lasting insecticide treated nets implementation. Methods Larvae and pupae of An. gambiae s.l. mosquitoes were collected from the breeding sites in Littoral, Zou, Borgou and Alibori provinces. CDC susceptibility tests were conducted on unfed females mosquitoes aged 2-5 d old. An. gambiae mosquitoes were identified to species using PCR techniques. Molecular assays were also carried out to identify kdr mutations in individual mosquitoes. Results The results showed that An. gambiae Malanville and Suru-lere populations were resistant to deltamethrin. Regarding An. gambiae Parakou and Bohicon populations, they were resistant to permethrin. PCR revealed 100% of mosquitoes tested were An. gambiae s.s. The L1014F kdr mutation was found in An. gambiae s.s. Malanville and Parakou at various allelic frequencies. The increase of kdr allelic frequency was positively correlated with CDC bioassays data. Conclusions Pyrethroid resistance is widespread in malaria vector in Benin and kdr mutation is the main resistance mechanism involved. More attention may be paid for the future success of malaria control programmes based on LLINs with pyrethroids in the country. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
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