24 April 2009

Update: Yellow fever in Brazil – expansion of risk areas

In 2009, yellow fever cases in monkeys and humans have been reported from areas of Brazil not previously considered risk areas for yellow fever. This illustrates that the situation for yellow fever in Brazil is dynamic. Health professionals and travellers should check the NaTHNaC website regularly for the latest information on risk areas.

Rio Grande do Sul

Between November 2008 and 23 April 2009, 18 confirmed human cases of yellow fever have been reported in eight municipalities of Rio Grande do Sul [1]. As of 9 April 2009, a further nine cases are under investigation. Monkey deaths due to yellow fever have been confirmed in 70 municipalities [2].

São Paulo

As of 8 March 2009, 22 confirmed human cases of yellow fever have been reported from the state of São Paulo. A further six cases are under investigation [3]. These cases were reported in the municipalities of Buri, Sarutaiá, Itatinga and Pirajú in areas outside the previously reported risk area. These areas are not within the boundaries of the city of São Paulo.

Expansion of risk areas

Since the NaTHNaC Clinical Update of 3 April 2009 [6], yellow fever activity in Rio Grande do Sul and São Paulo states has resulted in an expansion of areas in these states designated as having a risk for yellow fever transmission. (See map) [1-5].

Map of recent yellow fever activity in Brazil and expansion of risk areas

Advice for travellers

NaTHNaC now recommends vaccination for travellers over nine months of age visiting the newly expanded risk areas of Rio Grande do Sul and São Paulo states.  This is consistent with the advice issued by the Secretariats of Health of the states of Rio Grande do Sul and São Paulo.

Full vaccination recommendations for travellers to Brazil can be found on the NaTHNaC Country Information Pages.

Yellow fever is transmitted via the bite of an infected mosquito. In South America, the virus is transmitted via the bite of Aedes spp. mosquitoes (urban transmission from human to mosquito to human) or Haemogogus spp. (jungle transmission from monkey to mosquito to human) and Aedes spp. mosquitoes in Africa. These mosquitoes feed predominantly during daylight hours. Yellow fever can be prevented by taking mosquito bite avoidance measures and by vaccination.

Details of yellow fever vaccination recommendations because of risk, and requirements under International Health Regulations (2005) can be found on the NaTHNaC Country Information Pages.

References

1. Secretaria da Saude, Rio Grande do Sul. Novos números da febre amarela no Rio Grande do Sul, 23 April 2009. [Accessed 24 April 2009]. Available at: http://www.saude.rs.gov.br/wsa/portal/index.jsp?menu=noticias

&cod=41048

2. Secretaria da Saude, Rio Grande do Sul. Febre Amarela Silvestre, Rio Grande do Sul, 2008 e 2009. BOLETIM SEMANAL DO DIA 09/04/2009, 9 April 2009. [Accessed 22 April 2009]. Available at: http://www.saude.rs.gov.br/dados/1239294368033Boletim_FA-RS_09_04_09.pdf

3. Secretaria da Saude, Rio Grande do Sul. Febre Amarela Silvestre, Estado de São Paulo, 2009. BOLETIM DE ATUALIZAÇÃO – ENCERRADO ÀS 12h DO DIA 08/04/2009, 8 April 2009. [Accessed 22 April 2009]. Available at:  http://portal.saude.gov.br/portal/arquivos/pdf/Boletim_FA_SP_08

_2009CVE.pdf

4. Centro de Vigilância Epidemiológica, Rio Grande do Sul. Febre Amarela, Munícipios onde a vacinação é necessária, 9 April 2009. [Accessed 22 April 2009]. Available at: http://www.saude.rs.gov.br/dados/1239294642943VACINACAO

_09Abr.pdf

5. Centro de Vigilância Epidemiológica, São Paulo. Novas recomendações para vacinação contra febre amarela, 8 April 2009. [Accessed 22 April 2009.] Available at:  http://www.cve.saude.sp.gov.br/htm/zoo/fa09_novas_areaviaja.

htm

6. NaTHNaC. Update: Yellow fever in Brazil and Colombia and expansion of risk areas in Brazil, 3 April 2009. [Accessed 22 April 2009]. Available at:   http://www.nathnac.org/pro/clinical_updates/yf_030409.htm