Review and case report of a Bulgarian patient with Dobrava virus infection and associated haemorragic fever with renal syndrome

Hantaviruses are rodent-borne, negative-sense RNA viruses in the genus Hantavirus, family Bunyaviridae. The Balkan Peninsula is an endemic region for Haemorrhagic Fever with Renal Syndrome (HFRS), where Dobrava virus (DOBV) is established as one of the causes of the severe form of this disease. The first descriptions of HFRS in Bulgaria date back to 1955 and were followed by a series of studies in this area. The present study reviews the history of hantavirology in Bulgaria and describes a case of DOBV infection diagnosed by molecular methods that were recently introduced in the country. A sequence analysis of the PCR products was performed, a phylogenetic tree was constructed and the isolated strain from this patient was compared to DOBV strains originating from different regions. The partial nucleotide sequence from the S segment of the Bulgarian DOBV was found to be closely related to genetic variants of DOBV in the Balkan region, and especially to those in the Rhodopa Mountain region.