Are insecticide-treated bednets more protective against Plasmodium falciparum than Plasmodium vivax-infected mosquitoes?
GROUND: The outcomes of insecticide-treated bednet (ITN) interventions for malaria control in Papua New Guinea tend to suggest a differential protective effect against Plasmodium falciparum and Plasmodium vivax. Little is known about the impact of ITNs on the relative abundance of mosquitoes infected with either P. falciparum or P. vivax. This paper describes the biting cycle of P. falciparum and P. vivax-infected mosquitoes and the impact of an ITN intervention on the proportion of mosquitoes infected with either parasite species. METHODS: Entomological investigations were performed in East Sepik (ESP) and New Ireland Provinces (NIP) of PNG. Mosquitoes were collected using the all-night (18:00-06:00) landing catch and CDC light-trap methods and species specific malaria sporozoite rates were determined by ELISA. RESULTS AND DISCUSSION: The distribution of sporozoite positive mosquitoes in three four-hour periods (18:00-22:00, 22:00-02:00 & 02:00-06:00) showed that a higher proportion o
