A graduate student works on analyzing samples to identify the Zika virus in a laboratory at the Fiocruz institute in Rio de Janeiro, Brazil, Friday, Jan. 22, 2016. Health officials say they’re trying to determine if an unusual jump in cases of a rare nerve condition sometimes severe enough to cause paralysis is related to the spread of the mosquito-borne Zika virus in at least two Latin American countries. (AP Photo/Leo Correa)