Epidemiological update: Yellow fever outbreak in Brazil, 16 February 2017

Epidemiological update

As of 2 February 2017, 826 cases (including 155 confirmed) have been reported in Brazil. This represents an increase of 315 cases (including 67 confirmed) since the last CDTR. The most-affected state remains Minas Gerais, with 740 cases (including 138 confirmed) reported.

Yellow fever is a viral infection that is present in some tropical areas of Africa and South America. The virus is transmitted by mosquitoes, which also act as an important reservoir. Since 6 January 2017, Brazil has been experiencing an outbreak of yellow fever.

Weekly summary

On 9 February 2017, the state of Rio Grande do Norte reported its first suspected case of locally acquired yellow fever. Since the beginning of the outbreak in December 2016, six states have reported autochthonous transmission of yellow fever: Minas Gerais, Espírito Santo and São Paulo have reported confirmed cases, while Bahia, Tocantins and Rio Grande do Norte have reported suspected cases.
As of 9 February 2017, 1 038 cases (including 220 confirmed) have been reported in Brazil. This represents an increase of 212 cases (including 65 confirmed) since the last CDTR. The most-affected state remains Minas Gerais, with 900 cases (including 195 confirmed) reported.
Epizootics in non-human primates

Between 1 December 2016 and 9 February 2017, 623 epizootics in non-human primates were reported in Brazil, involving the death of 1 513 animals, 341 of which were confirmed for yellow fever.

Epidemiological summary

On 6 January 2017, Brazil reported an outbreak of yellow fever. The index case had onset of symptoms on 18 December 2016. The first laboratory confirmation was notified on 19 January 2017.
As of 9 February 2017, Brazil has reported 1 038 cases (818 suspected and 220 confirmed), including 180 deaths (103 suspected and 77 confirmed), in six states. The case fatality rate is 17.3% among all cases and 35.0% among confirmed cases.States reporting suspected and confirmed cases:

  • Minas Gerais has reported 900 cases (705 suspected and 195 confirmed), including 161 deaths (93 suspected and 68confirmed).
  • Espírito Santo has reported 113 cases (92 suspected and 21 confirmed), including 14 deaths (eight suspected and sixconfirmed).
  • São Paulo has reported nine cases (five suspected and four confirmed), including three confirmed deaths.
  • States reporting suspected cases:
  • Bahia has reported nine suspected cases, including one fatal case.- Tocantins has reported one suspected case, which was fatal.
  • Rio Grande do Norte has reported one suspected case, which was not fatal.

Investigations are ongoing to determine the probable infection site of five further suspected cases.
The Ministry of Health of Brazil has launched mass vaccination campaigns. As of 9 February 2017, 9.9 million extra doses of yellow fever vaccine have been sent to five states: Minas Gerais (4.5 million), Espírito Santo (2.5 million), São Paulo (1.2 million),Bahia (900 000) and Rio de Janeiro (850 000).
The 2017 Rio Carnival will take place from 24 to 28 February, with around one million tourists expected. According to the International Air Transport Association, 45 317 people (mainly from France, the United Kingdom and Portugal) travelled by airfrom the EU/EEA to the state of Rio de Janeiro during February 2015, when the 2015 Rio Carnival took place. As of 9 February 2017, no locally-acquired confirmed or suspected cases of yellow fever have been reported in this state since the beginning of the outbreak.

ECDC Assessment

The risk of yellow fever transmission in the EU/EEA is currently very low as it depends on the virus being introduced by viraemic travellers to an area with an established, competent and active mosquito vector population.In Brazil, authorities have reported only sylvatic cases in 2016 and 2017. However, this outbreak should be carefully monitored as the establishment of an urban yellow fever cycle would have the potential to quickly affect a large number of people. Therefore, EU/EEA Member States should consider a range of options for response.EU/EEA citizens who travel to, or live in, areas where there is evidence of yellow fever virus transmission, particularly in the states of Brazil reporting confirmed local transmission, should consider the risk of yellow fever, check their vaccination status and get medical advice about getting vaccinated against yellow fever.

ECDC monitors closely this event in collaboration with WHO. ECDC has published a rapid risk assessment on 26 January 2017. ECDC has also published an epidemiological update and a map for travel advice.

For detailed information on the distribution of yellow fever in Brazil see the regularly updated map and list of states with confirmed cases