For a little over two months we've been watching the steady spread of Yellow Fever in Brazil - starting in the interior state of Minas Gerais - and moving towards the coastal (and for years Yellow-Fever free) states of Espírito Santo and São Paulo.
In early February we saw the CDC issue a Level II Travel Notice: Yellow Fever in Brazil, while two weeks ago the WHO issue updated Yellow Fever Vaccination Recommendations For Brazil.
Last week the ECDC published Rapid Risk Assessment On Introduction Of Yellow Fever To Europe, while public health agencies in the United States ponder the risks of seeing imported cases showing up here.
Just as with Dengue, Chikungunya, Malaria, and most recently Zika, the potential for limited re-introduction of Yellow Fever to the United States and Europe - while low - is not zero (see Could Yellow Fever Return to the United States? by Peter Hotez and Kristy Murray).
Today the WHO has published a new update, where they now include the `State of Rio de Janeiro, with the exception of the urban areas of Rio de Janeiro City and Niterói, and the State of São Paulo, with the exception of the urban areas of São Paulo City and Campinas'
at risk for Yellow Fever transmission.
Disease outbreak news
20 March 2017
Updates on yellow fever vaccination recommendations for international travellers related to the current situation in Brazil As of 16 March 2017, yellow fever virus transmission continues to expand towards the Atlantic coast of Brazil in areas not deemed to be at risk for yellow fever transmission prior to the revised risk assessment, supported by the scientific and technical advisory group on geographical yellow fever risk mapping (GRYF), and published by WHO in the Disease Outbreak News of 27 January 2017 and 6 March 2017; as well as on the WHO International Travel and Health website on 31 January 2017,14 February 2017, and 6 March 2017.
As of 16 March 2017, confirmed cases of yellow fever virus infection in humans were reported in Rio de Janeiro State, and epizootics and human cases are under investigation for yellow fever virus infection in São Paulo State. These reports are consistent with the increased yellow fever activity observed in other States (Espírito Santo and Minas Gerais) that share the same ecosystem — tropical and sub-tropical broad leaved forests. As of 16 March 2017, there is no evidence of human cases of yellow fever virus infection transmitted by Aedes aegypti, the vector that could sustain urban transmission of yellow fever. Therefore, the WHO Secretariat has determined that the State of Rio de Janeiro, with the exception of the urban areas of Rio de Janeiro City and Niterói, and the State of São Paulo, with the exception of the urban areas of São Paulo City and Campinas, should also be considered at risk for yellow fever transmission.
Consequently, vaccination against yellow fever is recommended for international travellers visiting those areas in the States of Rio de Janeiro and São Paulo. The typology of activities that international travellers anticipate to undertake while visiting areas determined to be at risk for yellow fever transmission should be weighted in the risk-benefit analysis informing the individual decision to be immunized against yellow fever.
There are no other additional changes with respect to other areas of Brazil determined to be at risk for yellow fever transmission in 2013, as published by WHO in the Disease Outbreak News on 31 January 2017 and 6 March 2017.
The determination of new areas considered to be at risk for yellow fever transmission is an ongoing process and updates will be provided regularly. The current advice by the WHO Secretariat for international travellers going to areas of Brazil deemed to be at risk is the following:
Vaccination against yellow fever at least 10 days prior to the travel. Note that, as per Annex 7 of the International Health Regulations (2005), a single dose of a yellow fever vaccine approved by WHO is sufficient to confer sustained immunity and life-long protection against yellow fever disease. Travellers with contraindications for yellow fever vaccine (children below nine months, pregnant or breastfeeding women, people with severe hypersensitivity to egg antigens, and severe immunodeficiency) or over 60 years of age should consult their health professional for advice;
- Adoption of measures to avoid mosquito bites;
- Awareness of symptoms and signs of yellow fever;
- Seeking care in case of symptoms and signs of yellow fever, while travelling and upon return from areas at risk for yellow fever transmission.
For 2017, updates on requirements for the International Certificate of Vaccination or Prophylaxis, with proof of vaccination against yellow fever, and WHO vaccination recommendations for international travellers, are available on the WHO International Travel and Health website: Annex 1 and country list. More specific information about requirements for the International Certificate of Vaccination or Prophylaxis, with proof of vaccination against yellow fever, implemented by Member States in the Region of the Americas is available on the PAHO yellow fever website.