Vector alert: Anopheles stephensi invasion and spread in Africa and Sri Lanka

Vector alert: Anopheles stephensi invasion and spread in Africa and Sri Lanka

Anopheles stephensi, a highly competent vector of Plasmodium falciparum and P. vivax, is considered an efficient vector of urban malaria. Until 2011, the reported distribution of An. stephensi was confined to certain countries of South Asia and parts of the Arabian Peninsula. Since then, the vector has been collected in Djibouti (2012), Ethiopia (2016), Sudan (2016), Sri Lanka (2017), Somalia (2019), and most recently Nigeria (2020) and Yemen (2021). WHO considers the spread of An. stephensi to be a major potential threat to malaria control and elimination in Africa and southern Asia and has recently launched an initiative against the spread of this vector in Africa.

This vector alert supersedes a prior version released in 2019. It includes new data on the presence of the vector and lessons learned in recent years, particularly regarding surveillance. It also provides additional guidance to national malaria control programmes on specific responses to the spread of An. stephensi in Africa, as well as technical details on surveillance, analysis, and reporting.