Yellow Fever Alert in Brazil

The Centers for Disease and Control (CDC) has issued a level 2 travel warning for Brazil, urging anyone 9 months or older traveling to affected areas of Brazil to get vaccinated against yellow fever.

Those who were vaccinated against yellow fever more than 10 years ago should get a booster shot, the CDC said.

Brazil has seen 712 suspected cases of sylvatic yellow fever.

The rural state of Minas Gerais, has reported 40 deaths and 109 yellow fever cases from the mosquito-borne disease.

In addition to Minas Gerias, three other rural states, Espirito Santo, Bahia, and Sao Paulo, have reported cases.

"This is a fivefold increase in less than 1 month," said Duane Gubler, ScD, MS, former director of the CDC's Division of Vector-Borne Infectious Diseases. "That's an unusual number for sylvatic yellow fever."

Yellow fever is not a new threat to Brazil. In 2000, Brazil had an outbreak with 85 confirmed cases and 40 deaths.

"We have a tendency to assume everything is okay until it erupts into a real crisis," said Gubler. "If anyone could contain a yellow fever outbreak, Brazil could, but I'm still concerned with the large increase in cases."

The cases of sylvatic yellow fever are being spread by Haemagogus mosquitoes, which live in the country's jungles. During sylvatic outbreaks, mosquitos spread the flaviviridae virus among non-human primates, then humans.

Most sylvatic outbreaks are considered "spill-over outbreaks" and contained to the areas immediately surrounding the jungle.

But as seen in Angola, humans can carry the disease from rural to urban centers and spark a larger outbreak.

"Travelers can move yellow fever very quickly," said Gubler. "And as we saw with Zika this year, Brazil has a huge Aedes population in its cities."

Brazil is one of only a handful of countries in the world to manufacture its own yellow fever vaccine.

“When traveling into at-risk areas, getting the Yellow Fever vaccine is a safe bet,’ said Rannon Ching, Pharm.D, a travel vaccine specialist at Tarrytown Pharmacy in Austin, TX. “Access to the vaccination is one of the biggest barriers to becoming immunized.”

“Only CDC and state authorized yellow fever vaccination centers can administer the Yellow Fever vaccine. Some community pharmacies have certified staff available and offer online scheduling services to streamline the patient experience, Ching.”

According to the Brazilian government, 3.33 million doses of the vaccine have been distributed throughout Minas Gerais, and 1.55 million people have been vaccinated.

The price of the 17D yellow fever vaccine, ranges from $150 to $350.