Attachments
Main conclusions and options for response
The advancing epidemic of yellow fever in Angola in the past five months highlights the risk of infection for unvaccinated travellers, and the risk of further international spread through introduction of the virus into areas with a competent vector and susceptible populations. The identification of yellow fever among returning travellers to China, Kenya, Mauritania and the Democratic Republic of Congo represents a significant risk of further international spread, even in areas where it has not been transmitted in the past, such as China.
Outbreaks of yellow fever in urban settings have the potential for rapid spread and constitute a public health emergency, requiring mass immunisation campaigns for containment purposes. In the long term, introducing preventive immunisation through routine childhood vaccination in endemic countries can significantly reduce the burden of the disease.
Advice to travellers
Vaccination against yellow fever is recommended for all those ≥9 months old travelling to areas where there is evidence of persistent or periodic yellow fever virus transmission. WHO publishes a list of countries, territories and areas with yellow fever vaccination requirements and recommendations [1]. The yellow fever vaccine is recommended for travellers going to Angola. The country requirement specifies that a yellow fever vaccination certificate is required for travellers aged over 9 months. The certificate of yellow fever vaccination, which presently is valid for 10 years, will become valid for life in July 2016.
Prevention of importation
In the EU, the risk of yellow fever virus being introduced is limited to unvaccinated viraemic travellers coming from epidemic areas. Following the introduction of the virus, establishment of local transmission is possible in areas where Aedes aegypti mosquito is present and active. It is also possible in areas where Aedes albopictus is abundant, even though evidence supporting the Aedes albopictus mosquito’s competence to transmit yellow fever is weaker.
Countries with receptive areas for yellow fever transmission (presence of the relevant, active mosquitoes and naïve population for yellow fever) should consider stipulating the requirement of a yellow fever vaccination certificate for travellers coming from affected areas during the mosquito season.
Studies assessing the competence of the European Aedes albopictus mosquito populations and the capacity to transmit yellow fever need to be reviewed.
Advice to clinicians
Clinicians should consider yellow fever among travellers returning from affected areas. Suspected and confirmed patients should be prevented from being bitten by Aedes mosquito vectors in areas where they are present (for example through the use of a mosquito net).
Laboratory capacity in the EU
There is sufficient capacity in the EU for the detection of yellow fever through several reference laboratories