While cases of the birth defect-causing virus have dropped sharply from last year's peak in parts of Latin America and the Caribbean, Zika hasn't disappeared from the region and remains a potential threat. For now, pregnant women still are being urged not to travel to a country or area with even a few reported cases of Zika, because the consequences can be disastrous for a fetus' brain. The challenge is getting those messages to the people who most need it when Zika is fast receding from the public's radar — even as money may be drying up to track the virus and the babies it injures. The U.S.