In 2012, an unusual outbreak of urban malaria was reported from
Djibouti City in the Horn of Africa and increasingly severe out-
breaks have been reported annually ever since. Subsequent inves-
tigations discovered the presence of an Asian mosquito species;
Anopheles stephensi, a species known to thrive in urban environ-
ments. Since that first report, An. stephensi has been identified in
Ethiopia and Sudan, and this worrying development has prompted
the World Health Organization (WHO) to publish a vector alert
calling for active mosquito surveillance in the region. Using an
up-to-date database of published locational records for An. ste-
phensi across its full range (Asia, Arabian Peninsula, Horn of Africa)
and a set of spatial models that identify the environmental condi-
tions that characterize a species’ preferred habitat, we provide
evidence-based maps predicting the possible locations across Africa
where An. stephensi could establish if allowed to spread unchecked.
Unsurprisingly, due to this species’ close association with man-made
habitats, our maps predict a high probability of presence within
many urban cities across Africa where our estimates suggest that
over 126 million people reside. Our results strongly support the
WHO’s call for surveillance and targeted vector control and provide
a basis for the prioritization of surveillance.