Indoor use of plastic sheeting impregnated with carbamate combined with long-lasting insecticidal mosquito nets for the control of pyrethroid-resistant malaria vectors.

The combined efficacy of a long-lasting insecticidal net (LLIN) and a carbamate-treated plastic sheeting (CTPS) or indoor residual spraying (IRS) for control of insecticide-resistant mosquitoes was evaluated in experimental huts in Burkina Faso. Anopheles gambiae from the area is resistant to pyrethroids and to a lesser extent, carbamates. Relatively low mortality rates were observed with the LLIN (44%), IRS (42%), and CTPS (52%), whereas both combinations killed significantly more mosquitoes (~70% for LLIN + CTPS and LLIN + IRS). Blood feeding by An. gambiae was uninhibited by IRS and CTPS compared with LLIN (43%), LLIN + CTPS (58%), and LLIN + IRS (56%). No evidence for selection of the kdr and ace-1(R) alleles was observed with the combinations, whereas a survival advantage of mosquitoes bearing the ace-1(R) mutation was observed with IRS and CTPS. The results suggest that the combination of the two interventions constitutes a potential tool for vector-resistance management.