The World Health Organisation warned Thursday that efforts to halt the spread of measles were "backsliding", with case numbers worldwide surging around 50 per cent last year.
The UN health agency pointed to preliminary data showing that the disturbing trend of resurgent measles cases was happening at a global level, including in wealthy nations where vaccination coverage has historically been high.
"Our data are showing that there is a substantial increase in measles cases. We're seeing this in all regions," Katherine O'Brien, WHO's director of immunisation, vaccines and biologicals, told reporters in Geneva.
"We're having outbreaks that are protracted, that are sizable and that are growing," she said. "This is not an isolated problem."
O'Brien pointed out that less than 10 per cent of actual measles cases are reported.