Biosecurity

Zika: Two billion at risk in Africa and Asia, study says

More than two billion people could be at risk from Zika virus outbreaks in parts of Africa and Asia, according to scientists writing in The Lancet Infectious Diseases.

Populations in India, Indonesia and Nigeria are some of the most vulnerable to transmission, the researchers said.

They used data on air traveller numbers to help model their predictions.

However, they acknowledge that immunity to the virus could already exist in some areas and could reduce the risk.

The research team, from the London School of Hygiene and Tropical Medicine, Oxford University and the University of Toronto, Canada, said "vast numbers" of people were living in environments where it would be hard to prevent, detect and respond to the virus.