Yellow fever in Angola
Since December 2015, an outbreak of yellow fever (YF) has been ongoing in Angola. As of 10 April 2016, 1,751 suspected cases including 242 deaths (case fatality: 13.8%) have been reported in 17 of 18 provinces; 582 cases have been confirmed. Luanda, the capital of Angola, is the most affected province where 406 confirmed cases and 165 deaths have been reported. While cases are increasing in other affected provinces, including Huambo (85 confirmed cases) and Benguela (22 confirmed cases), there are some early indications that overall incidence is decreasing. Angola is a YF-endemic country but this is the worst outbreak to occur there in 30 years.
Cases have been reported in both Angolan nationals and expatriates resident in Angola, including nationals of Cape Verde, Democratic Republic of the Congo (DRC), Eritrea, India and Lebanon. At least six Chinese citizens have also died from YF while in Angola. In addition imported cases – in travellers who had recently returned from Angola – have been reported in China (nine cases), DRC (three cases), Kenya (two cases) and Mauritania (one case). In DRC, locally-acquired cases of YF are regularly reported; between early January and 22 March 2016, 151 suspected cases including 21 deaths had been reported, mostly in the northern part of the country not bordering Angola. Only four of these cases have been confirmed in DRC so far, of which three were acquired in Angola.
A vaccination campaign began in Luanda in early February to control the outbreak and, as of 10 April 2016, 90% of the target population had been vaccinated and case numbers in Luanda have decreased. Huambo province launched their vaccination campaign on 12 April and a campaign in Benguela is in preparation. Support for the response activities is being provided by the World Health Organization (WHO) and other international partners.
The yellow fever virus (YFV) can cause an illness that results in jaundice (yellowing of the skin and eyes) and bleeding with severe damage to the major organs (e.g. liver, kidneys and heart). The mortality rate is high in those who develop severe disease. YFV circulates between infected monkeys or humans and mosquitoes, and is a risk in tropical parts of Africa, South America, eastern Panama in Central America and Trinidad in the Caribbean. Areas with a “risk of YF transmission” (also known as endemic) are countries (or areas within countries) where mosquito species known to transmit the disease are present and where the infection is reported in monkeys and/or humans. Around 90% of reported YF cases occur in sub-Saharan Africa.
YF is a vaccine-preventable disease. In order to prevent the international spread of YF, under the International Health Regulations 2005) (IHR) , countries may require proof of vaccination, recorded in an International Certificate of Vaccination or Prophylaxis (ICVP). A Medical Letter of Exemption from vaccination may be taken into account by a receiving country, and can be considered in some circumstances if the vaccine is contraindicated.
Advice for travellers
Yellow fever is a rare cause of illness in travellers. Between 1970 and 2013, only 10 cases have been documented in unvaccinated travellers from the United States and Europe who travelled to risk areas in Africa or South America. The imported cases recently reported in China highlights the need to reinforce YF vaccine recommendations and certificate requirements for all travellers who visit countries with risk of yellow fever.
YF is transmitted by mosquitoes. All travellers visiting countries with a risk of any disease transmitted by mosquitoes should take insect bite avoidance measures, day and night.
As well as mosquito bite avoidance, vaccination is recommended for personal protection for anyone travelling to or through areas of Angola or any other countries with risk of yellow fever. Under the IHR, a yellow fever vaccination certificate is required from all travellers over 1 year of age travelling to Angola.Leave a reply →