Identification of a point mutation associated with pyrethroid resistance in the para-type sodium channel of Triatoma infestans, a vector of Chagas' disease.

The voltage-gated sodium channel is the target site of pyrethroid insecticides. Point mutations in the domain II region of the channel have been implicated in pyrethroid resistance of several insect species. We identified the sequence of domain II from the para sodium channel in Rhodnius prolixus, a vector of Chagas' disease. With this information, we cloned and sequenced the domain II of the sodium channel from the other main Chagas' disease vector: Triatoma infestans. We also identified the presence of a resistance-conferring mutation (L1014F) in a pyrethroid-resistant population of T. infestans from Argentina, and present a PCR-based method to detect this mutation in individuals from field populations. These findings have important implications for the implementation of strategies for resistance management, and for the rational design of campaigns for the control of Chagas' disease transmission.