In this Thursday, Feb. 25, 2016 photo, Caio Julio Vasconcelos who was born with microcephaly, undergoes physical therapy at the Institute for the Blind in Joao Pessoa, Brazil. 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)
In this Thursday, Feb. 25, 2016 photo, Caio Julio Vasconcelos who was born with microcephaly, undergoes physical therapy at the Institute for the Blind in Joao Pessoa, Brazil. 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) Andre Penner AP
In this Thursday, Feb. 25, 2016 photo, Caio Julio Vasconcelos who was born with microcephaly, undergoes physical therapy at the Institute for the Blind in Joao Pessoa, Brazil. 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) Andre Penner AP

Zika virus exposes weaknesses in public health

February 28, 2016 10:46 PM