WHO: Zika virus link to babies' small heads circumstantial
Brazil is hit by a large Zika outbreak and approcimately 4,000 cases of microcephaly.
"Although a causal link between Zika infection in pregnancy and microcephaly has not been established, the circumstantial evidence is suggestive and extremely worrisome," Director-general Dr. Margaret Chan said in a statement.
"An increased occurrence of neurological syndromes, noted in some countries coincident with arrival of the virus, adds to the concern."
The U.N. health agency announced plans to hold a special session in Geneva on Thursday to brief member states about Zika.
WHO spokesman Christian Lindmeier said the "big task" of health officials is to try to establish a link between the virus and microcephaly, which involves abnormally small heads in newborns and can affect brain development.
The virus, which has been around for decades, has no known link to cases of microcephaly, Lindmeier said, adding that a 1997 outbreak of Zika in Africa was not associated with any cases of microcephaly.
"That's why it's so important to look now into this connection and see what is going on there." ■