Rosana Vieira Alves uses a broken piece of mirror as she applies lipstick before taking her 4-month-old daughter Luana Vieira, who was born with microcephaly, to a doctor's appointment, at their house in Olinda, Brazil, February 4, 2016. The suspected link between the Zika virus and a birth defect known as microcephaly appears "stronger and stronger" as researchers study whether there is a causal connection, the head of the U.S. Centers for Disease Control and Prevention said on Friday. Picture taken February 4, 2016. REUTERS/Ueslei Marcelino