Assessment of risk of introduction of yellow fever in Cape Verde


In 2009, Cape Verde experienced a major outbreak of dengue serotype 3, with nearly 21,000 reported cases including 4 deaths in a hemorrhagic context. This epidemic has revealed the risk of introduction and efficient transmission of arbovirus within the archipelago. Yellow fever virus could be an emerging disease as a result of frequent exchanges between populations from islands of Cape Verde and some endemic areas such as West Africa and Brazil. But also because of the presence of the mosquito Aedes aegypti, a well-known vector of dengue virus and Chikungunya virus.

A multidisciplinary mission of 15 days was organized by WHO in response to a request by the Minister of Health of Cape Verde to assess the risk of introduction and endemic of yellow fever in Cape Verde and propose appropriate prevention measures.

The expert group brought together an epidemiologist at the Institut de Veille Sanitaire, a Nigerian epidemiologist from the African Network of WHO, a medical entomologist from the Institute Oswaldo Cruz (Brazil) and a virologist from the National Reference Centre for Arbovirus of the Pasteur Institut. A review of risk factors associated with yellow fever virus (source of introduction, type of rings available ...), capabilities for infectious disease surveillance and diagnostic capacity has been presented to the Minister of Health after the mission.

The main conclusions indicate a low potential risk for the introduction of yellow fever. Therefore there is no need for a massive vaccination campaign or immediate action by the population. A progressive immunization program associated with a strengthened border control were recommended. The continued efforts of vector control in the long term will limit the risk of yellow fever and especially the emergence of other arboviral much more probable as the other dengue serotypes, or that of the Chikungunya virus.