By Sereineat Nath

Several news outlets  have reported yellow fever outbreaks last week in Brazil. Brazil has had a disheartening start to 2017, with 555 suspected cases of yellow fever and 107 deaths reported. So far, 87 of the suspected cases have been confirmed, 26 have been discarded, and the remaining 442 remain under investigation. Among the deaths, 42 of the 107 are confirmed to have been a direct result of yellow fever infection. The suspected cases have been reported in the following Brazilian states: Minas Gerais, Espírito Santo, Bahia, São Paulo, Mato Grosso do Sul, Goiás, and the Federal District. The Brazilian Ministry of Health reported that, to date, there have only been records of wild yellow fever. Despite the fears of many that it will spread to urban areas, the last cases of urban yellow fever were recorded in 1942.


Yellow fever is typically found in tropical and subtropical areas across Africa and South America. For the outbreak in Brazil, the yellow fever virus was transmitted by semi-domestic (those that breed both in the wild and around households) mosquitoes (Aedes aegypti). Most of those infected only have mild symptoms for a short period of time, which may include fever, chills, vomiting, fatigue, and general body aches. However, approximately 15% of cases will develop into more serious symptoms, which can result in severe fever, jaundice, and/or hemorrhage. Approximately 20-50% of severe yellow fever cases result in death.

Treatments: CDC Recommendations

  • No specific treatments have been found to benefit patients with yellow fever. Whenever possible, yellow fever patients should be hospitalized for supportive care and close observation.
  • Treatment is symptomatic. Rest, fluids, and use of pain relievers and medication to reduce fever may relieve symptoms of aching and fever.
  • Care should be taken to avoid certain medications, such as aspirin or other nonsteroidal anti-inflammatory drugs (e.g. ibuprofen, naproxen), which may increase the risk of bleeding.
  • Yellow fever patients should be protected from further mosquito exposure (staying indoors and/or under a mosquito net) for up to 5 days after the onset of fever. This way, yellow fever virus in their bloodstream will be unavailable to uninfected mosquitoes, thus breaking the transmission cycle and reducing risk to the persons around them.

Yellow fever is prevented by an extremely effective vaccine, which is safe and affordable. A single dose of yellow fever vaccine is sufficient to confer sustained immunity and life-long protection against yellow fever disease and a booster dose of the vaccine is not needed. The vaccine provides effective immunity within 30 days for 99% of persons vaccinated.

In response to the outbreak, the governor of Minas Gerais has declared a 180-day state of emergency. In January, the Brazilian Ministry of Health distributed 650,000 doses of the yellow fever vaccine as standard monthly routine, and has since distributed an extra 5.4 million doses to the affected states. The Ministry of Health has created designated Yellow Fever Vaccine Recommendation Areas, and is encouraging everyone residing in, as well as anyone traveling to rural or forested regions within those areas, to get vaccinated.