Today, the Centers for Disease Control and Prevention (CDC) published an article in the Morbidity and Mortality Weekly Report (MMWR) and held a telebriefing on the topic of Zika virus infection among U.S. pregnant travelers.

Aedes aegypti/CDC
Aedes aegypti/CDC

As of February 17, CDC had received reports of nine pregnant travelers with laboratory-confirmed Zika virus disease; 10 additional reports of Zika virus disease among pregnant women are currently under investigation. No Zika virus–related hospitalizations or deaths among pregnant women were reported. Pregnancy outcomes among the nine confirmed cases included two early pregnancy losses, two elective terminations, and three live births (two apparently healthy infants and one infant with severe microcephaly); two pregnancies (approximately 18 weeks’ and 34 weeks’ gestation) are continuing without known complications. Confirmed cases of Zika virus infection were reported among women who had traveled to one or more of the following nine areas with ongoing local transmission of Zika virus: American Samoa, Brazil, El Salvador, Guatemala, Haiti, Honduras, Mexico, Puerto Rico, and Samoa.

CDC Director, Dr. Tom Frieden said, “The bottom line hasn’t changed from the time of our initial announcement.  If you’re pregnant, avoid travel to a place where Zika is spreading.  If you’re in a place such as Puerto Rico where Zika is spreading, do everything you can to avoid mosquito bites.  The most severe risk is to pregnant women.

“As of today, 147 cases have been reported to CDC. Of these, 107 are travel related cases in 24 states and the District of Columbia.  The other 40 are mostly locally acquired infections in U.S.  Territories.  Puerto Rico is by far the most affected area.  It makes the numbers a little confusing but I would like to indicate that today after closure of the CDC number that I just mentioned for the whole country including Puerto Rico from this past week, Puerto Rico posted their latest information which indicates that they have so far 117 known diagnosed cases.”

Approximately half a million pregnant women are estimated to travel to the United States annually from the 32 (as of February 18, 2016) Zika-affected countries and U.S. territories with active transmission of Zika virus. These numbers might decrease if pregnant women follow CDC recommendations and postpone travel to areas with ongoing local Zika virus transmission. Pregnant women and their partners should also be aware of the risk for Zika virus infection through unprotected sex with an infected male partner, and carefully follow CDC interim guidelines for preventing sexual transmission of Zika virus infection.