Caio Julio Vasconcelos who was born with microcephaly undergoes physical therapy at the Institute for the Blind in Joao Pessoa, Brazil, Thursday, Feb. 25, 2016. Researchers from the Centers of Disease Control and Prevention continue to fan out across one of Brazil's poorest states in search of mothers and infants for a study aimed at determining whether the Zika virus is causing babies to be born with unusually small heads. (AP Photo/Andre Penner), APTOPIX