Why The U.S. Government Is Advising Pregnant Women Not To Travel To Latin America

CREDIT: AP Photo/Felipe Dana

In this Dec. 23, 2015 photo, 10-year-old Elison, left, watches as his mother Solange Ferreira bathes Jose Wesley in a bucket at their house in Poco Fundo, Pernambuco state, Brazil. Ferreira says Jose Wesley enjoys being in the water, she places him in the bucket several times a day to calm him.

Pregnant women should postpone travel to over a dozen Latin American and Caribbean countries — and Puerto Rico — according to federal health officials fearing elevated risk of serious birth defects.

The Centers for Disease Control (CDC) has issued a “Level-2” travel alert in 14 countries and territories in the Western Hemisphere due to the startling spread of the Zika virus. Pregnant women, or women considering becoming pregnant, should exercise “enhanced precautions” when traveling to places where virus transmission is ongoing: Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela, and the Commonwealth of Puerto Rico.

“We believe this is a fairly serious problem,” Dr. Lyle R. Petersen, the CDC’s chief of vector-borne diseases said in a Friday evening teleconference. “This virus is spreading throughout the Americas. We didn’t feel we could wait.”

The Zika virus causes a painful fever in about 20 percent of those infected, which lasts up to a week. Fatalities are rare, but the real danger could lie in the shocking spike in birth defects in areas facing outbreaks. Brazilian health authorities have reported over 3,500 cases of microcephaly — infants born with abnormally small heads which can signal a seriously underdeveloped brain — in the last four months alone. Normally the country sees 150 cases annually. A direct causal link has not been proven yet, but scientists have found evidence of the virus in the wombs of women who gave birth to babies with microcephaly.

Issuing the alert before a definitive causal link between the virus and birth defects seems to indicate how worried health agencies are of Zika’s spread through the Americas. It appears to be the first time the CDC has recommended pregnant women avoid a particular region of the world.

“In parallel to the recent experience with chikungunya, Zika virus has the potential to rapidly spread across Latin America and the Caribbean,” stated a recent article in the Lancet. The study found that the United States was the top destination for travelers from Brazilian airports in affected areas, with 2.7 million in the prior year.

Zika is transmitted through bites from infected Aedes aegypti and Aedes albopictus mosquitoes, which thrive in warmer temperatures. These mosquitoes also transmit dengue fever and chikungunya. Recent research, including a 2014 NIH study, suggests that in a warming world the range of the Aedes mosquito will shift into new areas, specifically North America. Epidemiologists pointed to warmer winters and wetter springs as some of the reasons behind recent outbreaks of West Nile virus and dengue fever in the United States.

Preliminary data indicates that 2015 is likely to surpass 2014 for the hottest year on record.

This mosquito-borne virus was present in other parts of the world, but Brazil reported a case for the first time in May of last year. From there, the outbreak spread quickly, with estimates of between 500,000 and 1.5 million people infected in Brazil, and more in other Latin American countries. There is no vaccine to prevent Zika, nor medicine to treat the infected; the only advice health officials have for travelers to the region is to prevent mosquito bites.

Countries that have past or current evidence of Zika virus transmission (as of January 2016)

Countries that have past or current evidence of Zika virus transmission (as of January 2016)


Over a dozen cases of Zika have been reported in the mainland United States — including a recent case in Texas — but so far only in people who have recently traveled to infected areas. In December, Puerto Rico reported its first confirmed case in someone who had not recently traveled, meaning they caught it from a mosquito on the island.

The CDC’s Peterson said that the outbreak was a regional problem, with the risk for a pregnant woman traveling to Brazil not necessarily greater than traveling to another country on the list. However, with Brazil’s large outbreak and high tourism numbers, the

Brazil has recently fought outbreaks of dengue fever (also known as “breakbone” fever due to how painful an infection can be), with 1.6 million people infected in the past year. Concerns about global transmission spiked in 2014 when the country hosted the World Cup, and Brazilian authorities mounted a last-minute eradication effort that appears to have limited infections to very low levels for foreign tourists. Authorities have begun to launch a similar effort for the Zika virus, declaring a national emergency, deploying troops to search for pools of water which could serve as disease vectors, and pushing prevention and eradication.

UPDATE JAN 16, 2016 11:27 AM

Hours after the travel alert was announce last night, the Hawaii State Department of Health released CDC lab results of a prior Zika infection in a baby recently born on Oahu with microcephaly. The baby's mother was in Brazil last year when the baby acquired the infection in the womb. No cases of Zika have been reported acquired in Hawaii, though six people in the state got infected in another country. The New York Times confirmed the case Saturday.

“We are saddened by the events that have affected this mother and her newborn,” said DOH State Epidemiologist Dr. Sarah Park. “This case further emphasizes the importance of the CDC travel recommendations released today."

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