Zika virus 'spreading explosively,' World Health Organization chief warns

The Zika virus, blamed for a surge in birth defects, is "spreading explosively", World Health Organization chief Margaret Chan said Thursday, calling for an emergency meeting on the outbreak on February 1.

"The level of alarm is extremely high," Chan told a meeting of WHO member states in Geneva, calling for a February 1 meeting to determine if the outbreak qualifies as an international public health emergency.

The virus "is now spreading explosively," she added.

Chan said that during previous outbreaks the virus, which was first discovered in a monkey in Uganda in 1947, "occasionally caused a mild disease of low concern."

But "the situation today is dramatically different," she said, highlighting the growing concern that Zika has links to a birth defect known as microcephaly, or an abnormally small head.

"A causal relationship between Zika virus infection and birth malformations and neurological syndromes has not yet been established, but is strongly suspected," Chan said.

She explained that the February 1 Emergency Committee meeting will seek "advice on the appropriate level of international concern and for recommended measures that should be undertaken in affected countries and elsewhere."