As passenger screening begins at three United States airports, confusion is growing over the exact numbers of people infected by a mystery virus emerging in China.
Airports in Los Angeles, San Franciso and New York have begun screening passengers for symptoms of the virus which first appeared in the city of Wuhan in December.
There have been 49 laboratory-confirmed cases, but researchers at the Imperial College in London estimate the figure in China could be closer to 1700.
Two people are known to have died from the virus, which causes severe lung disease.
Professor of Public Health at the University of Otago, Michael Baker, speaks to Philippa Tolley.
