Epidemiology and molecular diversity of rabies viruses in Bulgaria.

A health emergency situation occurred in Bulgaria in 2007 when positive rabies cases were notified in Sofia district in the central-western part of the country, suggesting a southward spread of the disease for the first time in the last 10 years. Phylogenetic analysis on 49 isolates sampled between 2009 and 2011 showed, for the first time, evidence of the existence of NEE and D clustered lineages in Bulgaria. Their geographical distribution clearly reveals the permeability of natural barriers, as already suggested by the disease spread that occurred across the Balkan mountain range in 2007. The monitoring and passive surveillance programmes conducted since the first 2009 oral vaccination campaign, the spatio-temporal evolution of the disease in the country since 2007, and the need for further investigation of the role of jackals in virus dispersion are discussed.