Pregnant women in any trimester should consider postponing travel to 14 countries and territories in South and Central America and the Caribbean where mosquitos are spreading the Zika virus, the Centers for Disease Control and Prevention (CDC) announced tonight. Viral infection in pregnant women has been associated with microcephaly in infants.
In what it calls a level 2 travel alert, the CDC also advises women who are thinking about becoming pregnant to consult with their physician before traveling to these areas, and if they do, follow strict precautions to avoid mosquito bites. Safeguards include wearing long-sleeve shirts and long pants and using insect repellent.
The 14 countries and territories covered by the travel alert are Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela, and the Commonwealth of Puerto Rico.
Lyle Petersen, MD, director of the CDC's Division of Vector-Borne Diseases, told reporters at a 7 PM ET briefing that the travel alert couldn't wait until Monday.
"We believe this is a fairly serious problem," said Dr Petersen. "Because there's growing evidence of a link between Zika and microcephaly, we thought it was important to warn people as soon as possible."
Babies with microcephaly have a smaller-than-expected head. They often have smaller brains as well that may not have developed properly. Problems associated with microcephaly, which include seizures, developmental delays, intellectual and motor disabilities, and hearing loss can range from mild to life-threatening.
Microcephaly aside, the Zika virus normally does not cause illness that requires hospitalization or leads to fatalities. Roughly one in five people infected with the virus will develop symptoms such as fever, rash, joint pain, and conjunctivitis. The symptoms usually are mild and last a few days to a week. There is no vaccine to prevent Zika, or medicine to treat it.
Microcephaly Uncommon Here
Of the 14 countries and territories cited in the travel alert, Brazil troubles the CDC the most. The agency said Brazilian public health authorities have identified 3500 cases of microcephaly, some severe and fatal, between October 2015 and January 2016.
Cynthia Moore, MD, PhD, director of the agency’s Division of Birth Defects and Developmental Disabilities, told reporters tonight that this number represented a definite but unquantified increase over the normal incidence of microcephaly in Brazil. The baseline for the condition there, Dr Moore said, is hard to determine. However, even half of the reported cases "would be quite a large increase."
Brazilian health authorities provided the CDC with samples from two pregnancies that ended in miscarriages, and from two infants with microcephaly who died soon after birth. All four mothers said they had experienced Zika symptoms. CDC tests showed that the Zika virus was in the brain of the two full-term infants, and a genetic sequence analysis showed that the virus in all four cases matched that of the Zika virus circulating in Brazil.
Dr Petersen said his agency is working with Brazilian health authorities and other groups to better understand the link between the Zika virus and microcephaly.
Microcephaly is uncommon in the United States, affecting an estimated two to 12 babies per 10,000 live births, according to the CDC.
More information about the CDC travel alert is on the agency's website.