Brazilian and U.S. health workers from the United States' Centers for Disease Control and Prevention talk with a resident Wednesday, Feb. 24, 2016, as they search for mothers and infants to recruit for a study aimed at determining whether the Zika virus is causing babies to be born with a birth defect affecting the brain in Joao Pessoa, Brazil. Their goal is to persuade about 100 mothers of infants recently born with the defect as well to enroll in the study.