The relative impact of lambda-cyhalothrin and malathion was examined by conducting parasite prevalence surveys in 14 refugee villages in Pakistan before and after spray campaigns in 1993. The mosquito fauna usually comprised Anopheles stephensi, A. culicifacies, A. subpictus, A. superpictus, A. annularis and A. fluviatilis, among others. All villages had a history of malaria caused by Plasmodium vivax and P. falciparum. The spray campaign began in mid-July and lasted 6 weeks. The deposition rate of insecticides was calculated as 2.04 g of malathion 50% wettable powder (WP) per msuperscript 2 and 26 mg Icon 10% WP (lambda-cyhalothrin) per msuperscript 2 of room surface. Malaria parasite prevalence surveys were conducted on refugee school children (5-15 years) in June, before the insecticide intervention, and in November at the peak of the P. falciparum transmission season. Malathion-sprayed villages showed an increase in the prevalence of P. falciparum after intervention, and lambda-cyhalothrin-sprayed villages showed either a reduction or no change. Although lambda-cyhalothrin appeared to be more efficacious than malathion in reducing P. falciparum, its effect on the prevalence of P. vivax was not significantly different from that of malathion.
Rowland, M., Hewitt, S., & Durrani, N. (1994). Prevalence of malaria in afghan refugee villages in pakistan sprayed with lambdacyhalothrin or malathion. Transactions of the Royal Society of Tropical Medicine and Hygiene, 88(4), 378–379. https://doi.org/10.1016/0035-9203(94)90388-3