Outdoor biting and pyrethroid resistance as potential drivers of persistent malaria transmission in Zanzibar.

Background: Low-level of malaria transmission persist in Zanzibar despite high coverage of core vector control interventions. This study was carried out in hot-spot sites to better understand entomological factors that may contribute to residual malaria transmission in Zanzibar.

Methods: A total of 135 households were randomly selected from six sites and consented to participate with 20-25 households per site.