Molecular epidemiology of rabies virus in Romania provides evidence for a high degree of heterogeneity and virus diversity

Rabies has been present in Romania since antiquity and remains a continual threat to veterinary and public health. The current epizootic of rabies in Romania is fox mediated. However, little is known about the genetic diversity among rabies virus isolates from this part of the Balkan region. In this study, we analyzed a cohort of 64 rabies viruses isolated from infected animals in Romania collected between 2005 and 2008. Partial nucleoprotein sequence data (322 bp) were obtained and compared to a panel of available sequence data of Eurasian classical rabies virus (genotype 1) isolates. The Romanian sequences were identified as belonging to the cosmopolitan lineage of rabies viruses that have been reported throughout the world. The sequences showed a high degree of heterogeneity and six different lineages were identified. Single isolates clustered with the formerly established Eastern European group, the North-Eastern European group or with isolates from the Southwest of Russia. However two lineages were unique to Romania. This sequence diversity is unprecedented in European countries and could be a result of trans-border movement or remnants of previous epidemic waves.