By Julie Steenhuysen
CHICAGO (Reuters) - U.S. health officials are stepping up efforts to study the link between Zika virus infections and birth defects in infants amid predictions for widespread circulation of the mosquito-borne virus within the United States during warmer months.
The U.S. Director of the National Institutes of Health on Tuesday called for intensified efforts to study the impact of Zika infections, citing a recent study estimating the virus could reach regions where 60 percent of the U.S. population lives.
The mosquito-borne virus has been linked to brain damage in thousands of babies in Brazil. There is no vaccine or treatment for Zika, a close cousin of dengue and chikungunya, which causes mild fever and rash. An estimated 80 percent of people infected have no symptoms, making it difficult for pregnant women to know whether they have been infected. READ MORE