Invasive mosquito species spreading disease threat across African cities

An invasive mosquito species, Anopheles stephensi, is spreading across African cities and threatening to undo decades of progress against malaria, according to researchers tracking its expansion across the continent. Unlike Anopheles gambiae, the mosquito traditionally responsible for malaria transmission in sub-Saharan Africa, which breeds mainly in rural pools and prefers open countryside, Anopheles stephensi thrives in urban environments, laying eggs in water storage containers, discarded tires, construction sites and other artificial containers common in fast-growing cities. The species is native to South Asia and the Arabian Peninsula, where it has long been a major urban malaria vector in countries such as India and Pakistan. It was first detected in Africa in Djibouti in 2012, where it was linked to a sharp resurgence in malaria cases after years of decline. Since then it has been confirmed in Ethiopia, Sudan, Somalia, Nigeria, Kenya and several other countries, raising alarm among public health officials because it puts large, previously low-risk urban populations at risk of a disease historically concentrated in rural areas. The World Health Organization launched an initiative in 2022 to contain the mosquito's spread, urging affected countries to strengthen surveillance and adapt vector-control strategies designed for rural transmission patterns to dense city environments. Health experts warn that Africa's rapid urbanization, combined with inconsistent water storage practices and limited mosquito surveillance in cities, has created ideal conditions for the species to establish itself. Malaria remains one of the leading causes of death on the continent, and public health specialists say containing this urban vector is now a priority for regional and international health authorities working to sustain gains made against the disease over the past two decades.