More birth defects seen in parts of U.S. with local Zika spread
This is according to a report in CDC's Morbidity and Mortality Weekly Report (MMWR).
Areas with local transmission of Zika – southern Florida, a portion of south Texas, and Puerto Rico – saw a 21 percent increase in births with outcomes most strongly linked to Zika virus in the last half of 2016 compared with births in the first half of that year.
It is not known if this increase is due to local transmission of Zika virus alone, or if there are other contributing factors.
Most of the mothers who had babies with the Zika virus-linked birth defects did not have laboratory evidence of Zika virus infection—either because they were not tested, were not tested at the right time, or were not exposed to Zika virus.
All cases with birth defects potentially related to Zika virus infection are monitored by birth defects surveillance systems.
CDC looked at nearly 1 million births in 2016 in 15 U.S. states and territories, including Florida (select southern counties), Georgia (select metro-Atlanta counties), Hawaii, Iowa, Illinois, Massachusetts, New Jersey, New York (excluding New York City), North Carolina (select regions), Puerto Rico, Rhode Island, South Carolina, Texas (select regions), Utah, and Vermont.
About three out of every 1,000 babies born in 15 states and territories in 2016 had a birth defect possibly associated with Zika virus infection in the mother.
About half (49 percent) were born with brain abnormalities and/or microcephaly (small head size).
2 in 10 (20 percent) had neural tube defects and other early brain abnormalities.
1 in 10 (9 percent) had eye abnormalities without brain abnormalities.
More than 2 in 10 (22 percent) had nervous system damage, including joint problems and deafness, without brain or eye abnormalities.
Because many pregnant women exposed to Zika virus in late 2016 gave birth in 2017, CDC researchers anticipate that there could be another increase in possible Zika-related birth defects when 2017 data are analyzed. ■