eLife assessment
Connelly and colleagues provide convincing genetic evidence that importation from mainland Tanzania is a major source of Plasmodium falciparum lineages currently circulating in Zanzibar. This study also reveals ongoing local malaria transmission and occasional near-clonal outbreaks in Zanzibar. Overall, the manuscript effectively highlights the role of human movements in maintaining residual malaria transmission in an area targeted for intensive control interventions over the past decades and provides clear and valuable information for epidemiologists and public health professionals.