4 Pregnant Michigan Women Show Zika Symptoms: CDC

Four pregnant women in Michigan may have an infection from the Zika virus, the U.S. Centers for Disease Control and Prevention said in a new report Friday .

Overall, the CDC said, 157 pregnant women in the continental United States and 122 in its territories have tested positive for the virus that spreads through mosquito bites and sexual contact and can cause birth defects in babies of infected women.

The CDC said that in all of the cases in the continental U.S., the women got the Zika virus while traveling, and not in their local communities.

– Image credit: U.S. Centers for Disease Control and Prevention

Scientists are still learning about Zika, , but research has shown pregnant women may be infected without showing any symptoms, according to the CDC.

So the CDC is changing the way it tallies Zika cases for pregnant women.

Previously, the center was counting only the number of women who had both laboratory and symptomatic evidence.

Now, the CDC will report, “pregnant women who have any laboratory evidence of possible Zika virus infection.”

» Read more on about this developing story.