BACKGROUND: The causative agent of yellow fever is an arbovirus of the 
Flaviviridae family transmitted by infected Aedes mosquitoes, particularly in 
Africa. In the Central African Republic since 2006, cases have been notified in 
the provinces of Ombella-Mpoko, Ouham-Pende, Basse-Kotto, Haute-Kotto and in 
Bangui the capital. As the presence of a vector of yellow fever virus (YFV) 
represents a risk for spread of the disease, we undertook entomological 
investigations at these sites to identify potential vectors of YFV and their 
abundance.
FINDINGS: Between 2006 and 2010, 5066 mosquitoes belonging to six genera and 43 
species were identified. The 20 species of the Aedes genus identified included 
Ae. aegypti, the main vector of YFV in urban settings, and species found in 
tropical forests, such as Ae. africanus, Ae. simpsoni, Ae. luteocephalus, Ae. 
vittatus and Ae. opok. These species were not distributed uniformly in the 
various sites studied. Thus, the predominant Aedes species was Ae. aegypti in 
Bangui (90.7 %) and Basse-Kotto (42.2 %), Ae. africanus in Ombella-Mpoko 
(67.4 %) and Haute-Kotto (77.8 %) and Ae. vittatus in Ouham-Pende (62.2 %). Ae. 
albopictus was also found in Bangui. The distribution of these dominant species 
differed significantly according to study site (P < 0.0001). None of the pooled 
homogenates of Aedes mosquitoes analysed by polymerase chain reaction contained 
the YFV genome.
CONCLUSION: The results indicate a wide diversity of vector species for YFV in 
the Central African Republic. The establishment of surveillance and vector 
control programs should take into account the ecological specificity of each 
species.