JOAO PESSOA, Brazil—Teams of U.S. and Brazilian health workers ventured into dicey slums, fought through snarled traffic and braved torrential downpours on the first day of their effort to determine if the Zika virus is causing babies to be born with a birth defect affecting the brain.
The eight teams, each made up of one “disease detective” from the U.S. Centers for Disease Control and Prevention and three Brazilian health workers, went to work Tuesday in Paraiba, the impoverished state in northeastern Brazil that is one of the epicenters of the country’s tandem outbreaks of Zika and microcephaly.
Their goal is to persuade about 100 mothers of infants recently born with the defect as well to enroll in the study. They also need participation as controls of two to three times as many mothers from the same areas who delivered babies without microcephaly at about the same time.
