The Centers for Disease Control (CDC) reports that more than 3,500 pregnant women in the United States and U.S. territories showed laboratory evidence of possible Zika virus infection in 2016. Aggregated data reported to the U.S. Zika Pregnancy Registry as of Nov. 10, 2016, records 1,087 possible infections in the United States and the District of Columbia. An additional 2,451 possible cases in territories includes aggregated data from the U.S. territories reported to the U.S. Zika Pregnancy Registry and data from Puerto Rico reported to the Zika Active Pregnancy Surveillance System as of Nov. 10, 2016.

CDC did not provide a breakdown of where the cases are located in the U.S. and U.S. territories, although the agency has said Puerto Rico is in the midst of a Zika epidemic, noting that the situation in Puerto Rico warrants urgent, comprehensive action to protect pregnant women. The U.S. currently has 16 territories, with Puerto Rico, Guam, the Northern Mariana Islands, the U.S. Virgin Islands and American Samoa permanently inhabited. Eleven territories are small islands, atolls and reefs, spread across the Caribbean and Pacific, with no native or permanent populations.

The Zika virus can be passed from mother to baby during pregnancy and has been associated with microcephaly. Zika is primarily spread by infected mosquitos but can also be transmitted during sex. There is no vaccine or medicine to treat Zika, and CDC cautions pregnant women to avoid travel in affected regions.

Most of the pregnancies monitored by these systems are ongoing. CDC will not report outcomes until pregnancies are complete. These data reflect pregnant women in the U.S. Zika Pregnancy Registry and the Zika Active Pregnancy Surveillance System in Puerto Rico. CDC, in collaboration with state, local, tribal and territorial health departments, established these registries for comprehensive monitoring of pregnancy and infant outcomes following Zika virus infection. The agency cautions that these new numbers are not comparable to previous reports because the updated numbers reflect a different, broader population of pregnant women. READ MORE