A report released Thursday shows Zika had about the same impact on birth defects in Puerto Rico and other U.S. territories as it did in other places hit by the epidemic.
About 1 in 20 women infected with Zika had babies with birth defects in U.S. territories, according to the report. That's similar to what was seen in the rest of the United States and in Latin America and the Caribbean in the last two years.
The island territories — particularly Puerto Rico — are the U.S. locations hardest hit by the Zika epidemic. The tropical mosquitoes that spread Zika are more widespread there.
Most people infected with Zika don't get sick. It can cause a mild illness, with fever, rash and joint pain. But infection during pregnancy can lead to severe brain-related birth defects.
Thursday's report from the Centers for Disease Control and Prevention covered Puerto Rico, American Samoa, the Marshall Islands, the U.S. Virgin Islands, and the Federated States of Micronesia. It focused on women infected with Zika whose pregnancies had ended — through birth, miscarriage or abortion — from the beginning of last year through April.
There were 122 birth defects out of more than 2,500 pregnancies. The 5 percent rate is in line with other estimates about the risk of birth defects in Zika-infected pregnancies, including in the 50 states and the District of Columbia. The CDC didn't provide a breakdown, saying it was up to each territory to release the figure. It doesn't provide a state breakdown, either.
Last fall, the agency stopped reporting Zika numbers for U.S. territories because of a disagreement with health officials in Puerto Rico over how cases were being counted. Puerto Rico health officials cooperated with the new report, which uses the CDC method. The health department's website still lists only 38 cases of Zika-related birth defects, and health officials Thursday would not give the revised figure.. Other Zika data suggests the count would be closer to 100.
This week, Puerto Rico declared that its Zika epidemic is over. CDC officials on Thursday said they believe mosquitoes there are still carrying the virus and the CDC continues to advise pregnant women not to travel to the island.