Entomological evaluation of the risk of urban outbreak of yellow fever in 2008 in Abidjan, Côte d’Ivoire

Abstract

In April 2008, seven years after the outbreak of 2001, Abidjan faced another epidemic of yellow fever. Three weeks after the case detected in the commune of Treichville at 28(th) of April 2008, two other cases were notified, the first one in Port-Bouet and the second one in Cocody located respectively in the south and north of the city of Abidjan. In order to determine a large-scale risk of urban yellow fever epidemic, epidemiological and entomological investigations were conducted by the Ministry of Health and Public Hygiene of Cote d'Ivoire with the support of the Global Outbreak Alert and Response Network. Entomological investigations revealed the predominance of Aedes ægypti, urban vector of yellow fever in neighborhood visited with larval density indices between 2 and 5, indicating the existence of a sufficient density of the vector for cause an explosion of the epidemic. In fact, the massive influx of people from inside cities towards Abidjan caused by the socio-political crisis occurred in the country in 2002, the deterioration of environment with the creation of more breeding sites of Ae.ægypti as corollary and the circulation of the virus at mosquito level were many factors favorable to the yellow fever outbreak in Abidjan city.