IT's OFFICIAL : Zika Virus Causes Microcephaly And Other Birth Defects Even though confirmation is a huge step in Zika research, so many questions remain.

 04/13/2016 06:03 pm ET

Zika virus is the cause of microcephaly and other fetal brain defects, the U.S. Centers for Disease Control and Prevention confirmed Wednesday.

Zika Baby

While there isn’t yet “conclusive proof” that the mosquito-borne virus causes severe birth defects, health officials asserted that the totality of the research thus far clearly shows that there is a causal connection, and that there is good reason for pregnant women and their partners to protect themselves against mosquitoes in regions where Zika virus is spreading locally.

“We’ve now confirmed what mounting evidence has suggested, affirming our early guidance to pregnant women and their partners to take steps to avoid Zika infection and to health care professionals who are talking to patients every day,” said CDC director Dr. Tom Frieden in a statement. “We are working to do everything possible to protect the American public.”  

The CDC joins scientists from around the world who are also convinced the virus is a cause of microcephaly, as well as the rare neurological disorder Guillain-Barré syndrome. The World Health Organization released a statement about this global scientific consensus back in March, and CDC published their review of the scientific evidence linking Zika virus and microcephaly on Wednesday in the New England Journal of Medicine.

This causal relationship means that women who contract Zika virus while pregnant have an increased risk of giving birth to a baby with microcephaly and other brain defects. But it doesn’t mean that it will happen to all women who get Zika virus while pregnant.

More research is needed to establish the relative and absolute risk of having a baby with a birth defect, the CDC’s researchers write in their study review. Scientists also need to know the range of defects caused by a prenatal Zika virus infection, as well as explore any other factors that could influence birth defect risk. more