Eight more destinations have been added to the list of areas that federal health officials are urging pregnant women to avoid over concerns about transmission of the Zika virus and the risk of birth defects associated with the disease.
The Centers for Disease Control and Prevention on Friday warned pregnant women and women trying to get pregnant to forgo nonessential travel to Barbados, Bolivia, Ecuador, Guadeloupe, St. Martin, Guyana Cape Verde and Samoa.
Last week, the CDC issued a travel alert for Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela and Puerto Rico days after health officials in Texas confirmed the first U.S. case of Zika virus in a woman who had recently traveled to Latin America.
The virus has been spreading throughout Central and South America for the past year, with health officials in Brazil estimating more than 1 million cases since the start of the outbreak. It has been linked to 3,500 infants being born with microcephaly, a condition where the size of the baby's head is significantly smaller than normal.
Infected cases related to travel have recently been found in Florida, Hawaii, Illinois and Texas, which health officials say have all been related to travel to Central and South American locations.
There have been no known cases thus far of local transmission of the disease, but many infectious disease experts say that it is only a matter of time before it spreads throughout the southern parts of the U.S. as warmer temperatures bring an increase in mosquitoes, which carry the virus.
“I'm guessing there are probably dozens of cases that are not being diagnosed,” said Dr. Peter Hotez, founding dean of the National School of Tropical Medicine at Baylor University's College of Medicine. “The big issue is going to be, 'Could transmission start happening here on the Gulf Coast?' ”
Hotez said a number of factors, in addition to the tropical climate, make the region particularly susceptible for a potential outbreak. One has to do with the fact that the two types of mosquitoes that are known for carrying the disease, the Aedes aegypti and Aedes albopictus, both thrive in the southern U.S.
Another factor that could put the area at higher risk is the large scale of human travel that goes on within the area, which Hotez said would make it easier for the virus to take root since it can be days before a traveler experiences symptoms.
A fourth concern regarding Zika is related to the extreme poverty found within the Gulf Coast, which Hotez said makes the region vulnerable because of poor housing quality that fails to effectively keep mosquitoes out. Hotez said that for those reasons, he believed cases of local transmission in the U.S. could begin occurring as soon as the spring or summer.
“If that were the case, then you would have to worry about congenital infections nine months from then,” Hotez said. “So we have a window period right now to figure out what we're going to do in terms of accurate surveillance for the disease and public health control.”