The Centers for Disease Control and Prevention recommends that travelers who haven’t been vaccinated against yellow fever should avoid travel to Brazil, according to a media teleconference by CDC officials.

“The most important new recommendation … is that travelers should not go to these yellow fever hot spots in Brazil, unless they are vaccinated,” stated Martin Cetron, MD , director of the Division of Global Migration and Quarantine at the CDC. “Health officials in Brazil recently confirmed more than 920 cases of yellow fever, including more than 300 deaths, during this outbreak” he added.

Yellow fever is a fairly common infection in locations such as South America, and is spread by the bite of an infected mosquito, according to Dr. Cetron. He pointed out that Brazil’s yellow fever outbreak has been spreading into areas popular with tourists, including urban centers such as Rio De Janeiro.

Since the beginning of 2018, 10 travel-related cases of yellow fever have been reported among international travelers returning from Brazil. Four of these travelers died. All 10 travelers had not received the yellow fever vaccine. Of these 10 travelers, 8 acquired the disease on Ilha Grande, an island off the coast of Rio De Janeiro that is popular among tourists.

The CDC is urging travelers to get vaccinated because of the potentially fatal effects of yellow fever. Vaccinations are recommended for any eligible person 9 months of age or older traveling to Brazil, specifically Espírito Santo, São Paulo, and Rio de Janeiro states, and certain cities in Bahia state, as well as Ilha Grande in particular.

Individuals heading to Brazil should receive the vaccination at least 10 days before travel. If a traveler is unvaccinated and cannot get the vaccination in the appropriate amount of time, areas where vaccination is recommended should be avoided.

The Food and Drug Administration–approved yellow fever vaccine, YF-VAX, is not currently available because of manufacturing issues. Stamaril, another yellow fever vaccine, is available at a limited number of yellow fever vaccination clinics in the United States.

In light of these supply issues, the CDC has provided resources to locate yellow fever vaccination clinics .

Dr. Cetron reemphasized that unvaccinated individuals planning to vacation in Brazil may want to reconsider their travel plans.

“People who have never been vaccinated against yellow fever should not travel to the areas in Brazil affected by the outbreak. Particularly the hot spot of Ilha Grande.”

Information for clinicians and travelers is available on the travel notice portion of the CDC site. The travel notice for Brazil includes a map of the yellow fever–affected areas in Brazil, as well as other informational resources.

The related CDC Morbidity and Mortality Weekly Report is available online.