Findings show need for strong birth-defect surveillance networks Birth defects most strongly linked to Zika virus infection during pregnancy have increased in parts of the United States that have had local Zika virus transmission, according to a report in CDC's Morbidity and Mortality Weekly Report (MMWR). Areas with local transmission of Zika – southern Florida, a portion of … [Read more...] about More birth defects seen in parts of U.S. with local Zika spread