Risk of International Spread of Yellow Fever Re-assessed in Light of Ongoing Outbreaks

Suspected and confirmed cases of yellow fever by province of reporting, Angola, Dec. 5, 2015 through May 22, 2016. Courtesy of ECDC
 
The European Centre for Disease Prevention and Control (ECDC) has updated its rapid risk assessment on the outbreak of yellow fever with the latest developments, more comprehensive information on the current situation in Angola, Democratic Republic of Congo (DRC) and Uganda and an extended threat assessment for the EU. Some of the data used in the assessment were collected during a mission to Angola in May 2016.

From Jan. 21, 2016 to May 22, 2016, the Angolan Ministry of Health notified health authorities of 2,536 yellow fever cases, of which 747 were confirmed and 301 fatal. The number of new suspected and confirmed cases in Angola has been decreasing and a mass vaccination campaign has already reached about half of the targeted population. However, the outbreak in Angola is not yet under control and is currently expanding to additional provinces, further challenging the ongoing mass vaccination campaign. Currently, all regions in Angola should be considered as areas at high risk of transmission of yellow fever.

The yellow fever outbreak in Uganda is unrelated to the outbreak in Angola. Between March 26, 2016 and May 19, 2016, health authorities reported 60 yellow fever cases, including seven deaths in six different districts. As of May 23, DRC has reported 590 cases of yellow fever, 41 of these had a recent travel history to Angola.

Viraemic patients traveling to areas where suitable vectors and susceptible human populations are present pose a risk for local transmission. Such areas exist in most of the inter-tropical zones of Africa, and the Americas and Asia. Therefore, the risk of international spread within Africa and beyond is currently high.
 
In the EU/EEA, the risk of yellow fever virus being introduced is limited to unvaccinated viraemic travelers coming from areas with active local transmission. Given that outbreaks of yellow fever in urban settings have the potential for rapid spread and that significant yellow fever epidemics are ongoing in Angola, DRC and Uganda, a range of options for response by EU/EEA Member States are presented in the updated rapid risk assessment. These options emphasize the importance of vaccination of travelers and those leaving Angola, preventive measures against mosquito bites in affected areas, as well as awareness raising among clinicians to consider this diagnosis in returning travelers.

Source: European Centre for Disease Prevention and Control (ECDC)