Daniele Santos, holds her son Juan Pedro who is 2-months-old and born with microcephaly, after taking...
Daniele Santos, 29, holds her son Juan Pedro who is 2-months-old and born with microcephaly, after bathing him at their house in Recife, Brazil, February 9, 2016. The Zika virus may be particularly adept at entrenching itself in parts of the body that are shielded from the immune system, making it harder to fight off and possibly lengthening the timeframe in which it can be transmitted, top U.S. experts said on Friday. Picture taken February 9, 2016. REUTERS/Nacho Doce