Why is resistance an important public health issue?

The development of pyrethroid resistance in Anopheles gambiae has been highlighted in recent years due to the increased reliance on pyrethroid treated nets for malaria prevention and control. To date, pyrethroids are the only class of chemical approved by the WHO for use on mosquito nets. In the last decade, kdr resistance has become widespread in West Africa and also been detected in East Africa. Previously, pyrethroid treated nets have remained effective even in areas with high levels of the kdr gene. However, in 2007 the first report¹ of the reduced efficacy of pyrethroid treated ITNs in an area of high kdr resistance was published and it is likely that if current trends continue, insecticide resistance may compromise control as it did in the last era of malaria eradication in the 1950’s and 60’s².

References

1. N'Guessan, R. et al. (2007) Reduced efficacy of insecticide-treated nets and indoor residual spraying for malaria control in pyrethroid resistance area, Benin. Emerg Infect Dis 13(2): 199-206.
2. Kelly-Hope, L., H. et al. (2008) Lessons from the past: managing insecticide resistance in malaria control and eradication programmes. Lancet Infect Dis 8(6): 387-9.