Review of the evolution of insecticide resistance in main malaria vectors in Cameroon from 1990 to 2017

Antonio-Nkondjio, Christophe; Sonhafouo-Chiana, Nadège; Ngadjeu, Carmène Sandra; Doumbe-Belisse, Patricia; Talipouo, Abdou; Djamouko-Djonkam, Landre; Kopya, Edmond; Bamou, Roland; Awono-Ambene, Parfait; Wondji, Charles S.

doi:10.1186/s13071-017-2417-9

Cited by 100 publications

(129 citation statements)

References 58 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…This high resistance in An. gambiae is in line with the increased resistance reported in this species in several sites across Cameroon [14, 17–20]. The resistance in An.…”

Section: Discussionsupporting

confidence: 78%

“…has been associated with nearly fixed kdr allele in the population, as observed recently in DR Congo [38], or previously in Côte d’Ivoire [44]. However, this high level of kdr is in contrast to frequencies observed in other locations across Cameroon as highlighted by a recent review [17]. The very low frequency of the 1014S kdr allele in Mibellon is similar to previous reports across Cameroon showing that this marker, originally present in East Africa, has now migrated to Central and West Africa although still at very low frequencies [45].…”

Section: Discussionmentioning

confidence: 76%

See 1 more Smart Citation

Bionomics and insecticides resistance profiling of malaria vectors at a selected site for experimental hut trials in central Cameroon

Menze

Wondji

Tchapga

et al. 2018

Malar J

Self Cite

View full text Add to dashboard Cite

BackgroundMalaria vectors are increasingly developing resistance to insecticides across Africa. The impact of such resistance on the continued effectiveness of insecticide-based interventions remains unclear due to poor characterization of vector populations. This study reports the characterization of malaria vectors at Mibellon, a selected site in Cameroon for experimental hut study, including species composition, Plasmodium infection rate, resistance profiles and mechanisms.MethodsIndoor resting blood-fed Anopheles mosquitoes were collected from houses at Mibellon in 2017 and forced to lay eggs to generate F1 adult mosquitoes. Insecticides susceptibility bioassays were performed on the F1 adult mosquitoes following the WHO protocol to assess resistance profile to insecticides. The molecular basis of resistance and Plasmodium infection rate were investigated using TaqMan genotyping.ResultsAnopheles funestus sensu stricto (s.s.) was predominant in Mibellon (80%) followed by Anopheles gambiae s.s. (20%). High levels of resistance to pyrethroids and organochlorides were observed for both species. Moderate resistance was observed against bendiocarb (carbamate) in both species, but relatively higher in An. gambiae s.s. In contrast, full susceptibility was recorded for the organophosphate malathion. The PBO synergist assays with permethrin and deltamethrin revealed a significant recovery of the susceptibility in Anopheles funestus s.s. population (48.8 to 98.1% mortality and 38.3 to 96.5% mortality, respectively). The DDT/pyrethroid 119F-GSTe2 resistant allele (28.1%) and the dieldrin 296S-RDL resistant (9.7%) were detected in An. funestus s.s. The high pyrethroid/DDT resistance in An. gambiae correlated with the high frequency of 1014F knockdown resistance allele (63.9%). The 1014S-kdr allele was detected at low frequency (1.97%). The Plasmodium infection rate was 20% in An. gambiae, whereas An. funestus exhibited an oocyst rate of 15 and 5% for the sporozoite rate.ConclusionThese results highlight the increasing spread of insecticide resistance and the challenges that control programmes face to maintain the continued effectiveness of insecticide-based interventions.

show abstract

“…This high resistance in An. gambiae is in line with the increased resistance reported in this species in several sites across Cameroon [14, 17–20]. The resistance in An.…”

Section: Discussionsupporting

confidence: 78%

Section: Discussionmentioning

confidence: 76%

Bionomics and insecticides resistance profiling of malaria vectors at a selected site for experimental hut trials in central Cameroon

Menze

Wondji

Tchapga

et al. 2018

Malar J

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although no IRS campaign has been carried out in the country so far, the National Malaria Control Program and PMI have identified the North and Far North, as the promising targets for a future implementation of IRS [55]. Most anopheline populations across the country are already highly resistant to pyrethroids and sometimes to several other classes of insecticide including carbamates, organophosphates and organochlorines (reviewed in [56]). In such multi-resistant populations, cross-resistance to insecticides with similar modes of action may contribute to the build-up of tolerance to new insecticides [57].…”

Section: -Oxydases Play a Central Role In Clothianidin Resistance Inmentioning

confidence: 99%

Resistance to clothianidin reduces the efficacy of SumiShield® 50WG, a neonicotinoid formulation for indoor residual spraying, againstAnopheles gambiae

Fouet

Ashu

Ambadiang

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Background: New active ingredients, mostly repurposed from the agricultural sector, are gradually being introduced into malaria vector control programs. Prior to scaling up novel insecticides, it is vital to assess if their use in agriculture has already selected mosquito populations with reduced susceptibility in some areas. The aim of the present study was to determine if the use of neonicotinoids in agricultural pest management could drive resistance to clothianidin - a neonicotinoid recently prequalified by WHO for indoor residual spraying. Methods: We carried out intensive sampling of Anopheles gambiae, An. coluzzii and Culex sp. larvae from a large suburban farm and from 4 surrounding locations belonging to the rural and urban ecosystems of Yaounde, Cameroon. Using WHO tube tests and CDC bottle bioassays, we tested the recommended diagnostic doses of clothianidin against field-collected populations using two laboratory strains as susceptible controls. We exposed adult mosquitoes to the insecticide for 1 h and monitored mortality rates for seven consecutive days. Results: An. coluzzii and Culex sp. mosquitoes were fully susceptible to clothianidin reaching 100% mortality by day 3. By contrast, An. gambiae populations revealed heterogeneous profiles ranging from susceptibility to strong resistance. Populations from the suburban farm, where neonicotinoids are routinely used, displayed the lowest mortality rate (46.5 % ± 5.65) and were capable of surviving 5X and 10X the diagnostic dose of clothianidin. When clothianidin was tested in combination with the synergist piperonyl butoxide, mortality of resistant populations increased from 46.5 % to 92.7 % implying that Cytochrome P450 enzymes play an integral role in the genetic mechanism underlying clothianidin resistance in An. gambiae. Conclusions: These findings show that small clusters of resistance to clothianidin may exist around farmlands where agricultural neonicotinoids are being used. Patches of intensive agriculture should be particularly monitored in indoor residual spraying target areas.

show abstract

“…Moreover, to further strengthen the current vector control intervention, an indoor residual spray (IRS) campaign is to be launched in Cameroon for the first time by the United States President Malaria Initiative (PMI) project. Unfortunately, the wide spread nature of insecticide resistance in malaria vectors to common insecticides used to impregnate nets and spray walls in Cameroon [6][7][8][9][10] threatens the success of this strategy.…”

Section: Introductionmentioning

confidence: 99%

Elevated Plasmodium infection and multiple insecticide resistance in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the airport of Yaoundé, the Capital city of Cameroon

Nongley¹,

Mbugulize²,

Terence³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Background Reducing the burden of malaria requires better understanding of vector populations particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the international airport of Yaoundé, the capital city of Cameroon, including species composition, abundance, Plasmodium infection rate; insecticide resistance profiles and underlying resistance mechanisms. Methods Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a village located 2km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F 1 adult progeny. WHO bioassays were performed to assess resistance profile to insecticides. The threshold of insecticide susceptibility was fixed above 98% mortality rate and mortality rates below 90% were considered indicative of confirmed insecticide resistance according to the WHO test procedures for insecticide resistance monitoring. Furthermore, the molecular basis of resistance and Plasmodium infection rates were investigated.Results Anopheles funestus s.s. was most abundant species in Elende (85%) followed by Anopheles gambiae s.s. (15%) with both having a similar sporozoite infection rate. Both species exhibited high levels of resistance to pyrethroids (<40% mortality). An. gambiae s.s. was also resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate. An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The DDT/pyrethroid L119F-GSTe2 resistance allele (8%) and G119S ace -1 resistance allele (15%) were detected in An. funestus s.s. and An. gambiae s.s. respectively. Furthermore, the high pyrethroid/DDT resistances in An. gambiae s.s. corresponded with an increase frequency of 1014F kdr allele (95%). The CYP6P9a P450 resistance allele was absent in the An. funestus s.s. population meanwhile transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression of CYP6P5 , CYP6P9a and CYP6P9b. Conclusion The resistance to multiple insecticide classes observed in these vector populations alongside the high Plasmodium infection rate highlights the challenges that public health vector control programs encounter in sustaining the regular effectiveness of contemporary insecticide-based control interventions in forested areas. More particularly, the resistance observed against the carbamates and possible resistance against the organophosphates constitutes a major concern for IRS.

show abstract

Review of the evolution of insecticide resistance in main malaria vectors in Cameroon from 1990 to 2017

Cited by 100 publications

References 58 publications

Bionomics and insecticides resistance profiling of malaria vectors at a selected site for experimental hut trials in central Cameroon

Bionomics and insecticides resistance profiling of malaria vectors at a selected site for experimental hut trials in central Cameroon

Resistance to clothianidin reduces the efficacy of SumiShield® 50WG, a neonicotinoid formulation for indoor residual spraying, againstAnopheles gambiae

Elevated Plasmodium infection and multiple insecticide resistance in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the airport of Yaoundé, the Capital city of Cameroon

Contact Info

Product

Resources

About