With an ongoing outbreak of potentially deadly yellow fever in Brazil, the Centers for Disease Control and Prevention (CDC) is recommending that all travelers to affected areas of the country get vaccinated before they go. But following the recommendation is made somewhat difficult by the fact that the vaccine only has limited availability in the U.S. right now.
"In the last two years or so, Brazil's yellow fever outbreak has expanded significantly, moving closer to popular tourist destinations on the coast and near the coast and in major urban areas like Rio de Janiero and Sao Paulo," Dr. Marty Cetron of the CDC's Division of Global Migration and Quarantine said on a call with media Friday. "We have also had recent reports of yellow fever cases and deaths in travelers."
The CDC has updated its guidance for travelers, recommending vaccinations for anyone traveling to Espirito Santo state; Sao Paulo state, including the city of Sao Paolo and all coastal islands; Rio de Janiero state, including the city of Rio de Janeiro and all coastal islands; and some cities in Bahia state. A map of affected areas is available on the CDC's website.
Cetron said more than 2 million U.S. Americans visit Brazil annually.
At the same time, the only yellow fever vaccine licensed in the U.S., YF-Vax, is unavailable and expected to remain as such until the end of the year.
Another vaccine, Stamaril, has been made available in its place, but is only available at around 250 clinics around the United States, meaning some travelers will have to travel far to take the recommended precautions before visiting Brazil. In contrast, about 4,500 clinics had YF-Vax. A map of clinics that have Stamaril is available online.
"We know this has been, and will continue to be, inconvenient and frustrating for some travelers," Cetron said.
However, "it may be hard to get, but it's worth the extra effort," he said.
According to the CDC, yellow fever is spread through mosquitoes. Symptoms, which take around three to six days to develop, include fever, chills, headache, backache and muscle aches. Among those who contract the virus, about 15% develop serious conditions, including bleeding, shock and organ failure. It also sometimes leads to death.
According to the CDC, the outbreak in Brazil began in December 2016. There have been 10 travel-related cases of the virus, including four deaths. None of those cases were reported in U.S. travelers.
In eight of those travel-related cases, the virus was acquired on Ilha Grande, a forested island off the coast of Rio de Janeiro. Those cases include the four deaths.
Cetron said the travelers who contracted yellow fever were all unvaccinated. The CDC recommends travelers to Brazil get vaccinated at least 10 days before their trips.
Dr. Lyle Peterson, director of the CDC's Division of Vector-Borne Diseases, said two genus of mosquito transmit yellow fever: the forest-dwelling Haemagogus and the urban Aedes. Aedes mosquitoes are the same kind that spread diseases like the Zika virus and chikungunya.
The Aedes mosquito can be found in southern areas of the United States. While Peterson said it is possible to see some transmission of the disease in areas of the U.S. where the mosquito is found, at this point, the CDC does not believe it is likely.
For more information on yellow fever and the CDC's recommendations, visit https://www.cdc.gov/yellowfever/.