The number of confirmed yellow fever cases in the Brazil outbreak, which began in December 2016, has grown to 149, including 52 confirmed fatalities, according to the Brazilian Health Ministry today (computer translated).

Aedes aegypti/CDC
Aedes aegypti/CDC

Five states report suspected/confirmed yellow fever cases–Minas Gerais, Espírito Santo, Bahia, São Paulo and Tocantins. Minas Gerais accounts for nine out every 10 confirmed yellow fever cases in the country.

There is some apparent good news as one infectious disease specialist believes the outbreak may have peaked. Dirceu Bartolomeu Greco, an infection specialist and professor at the School of Medicine of the Federal University of Minas Gerais in Belo Horizonte said, “I think we may have reached the peak of the current outbreak. This serves as a very important reminder that the preventive part of this is perhaps the most important. I think this outbreak will be controlled.”

The outbreak, the largest in Brazil since 2000, has prompted the US Centers for Disease Control and Prevention (CDC) to issue a travel notice for travelers to the South American country.

The Brazilian Ministry of Health maintains a list of all other municipalities in Brazil for which yellow fever vaccination continues to be recommended (not including recently added municipalities).

Anyone 9 months or older who travels to these areas should be vaccinated against yellow fever. People who have never been vaccinated against yellow fever should not travel to areas with ongoing outbreaks. CDC no longer recommends booster doses of yellow fever vaccine for most travelers. However, a booster dose may be given to travelers who received their last dose of yellow fever vaccine at least 10 years ago and who will be in a higher-risk setting, including areas with ongoing outbreaks.

Because of the ongoing outbreak, travelers to the Brazilian states of Minas Gerais, Espirito Santo, and parts of Bahia, Sao Paulo, and Rio de Janeiro states may consider getting a booster if their last yellow fever vaccination was more than 10 years ago. Travelers should consult with a yellow fever vaccine provider to determine if they should be vaccinated.

Yellow fever is a disease caused by a virus spread by mosquito bites. Symptoms take 3–6 days to develop and include fever, chills, headache, backache, and muscle aches. About 15% of people who get yellow fever develop serious illness that can lead to bleeding, shock, organ failure, and sometimes death.