Iva Christova
National Center of Infectious and Parasitic Diseases, Bulgaria
Title: Vector borne infections in Bulgaria
Biography
Biography: Iva Christova
Abstract
Located in Southeastern Europe, Bulgaria is an endemic country for Lyme borreliosis and Crimean-Congo haemorrhagic fever (CCHF) and is affected by West Nile virus (WNV). In addition, sporadic cases of Tick-borne encephalitis (TBE) have been also reported. About 500 cases of Lyme borreliosis are detected annually in Bulgaria. Two peaks in the seasonal distribution of cases and more frequent presentation of neuroborreliosis than of Lyme arthritis appear to be characteristics of Lyme borreliosis in the country. With sporadic cases or small outbreaks, CCHF appeared every year. More than 1600 CCHF cases were officially recorded since 1952. Genetic investigations showed that CCHF virus strains causing disease in the country belong to lineage Europe 1. However, two CCHF virus lineages, Europe 1 and Europe 2, are present in ticks in Bulgaria. CCHF seroprevalence among healthy population is 3.7%. In 2018, number of detected WNV human cases in Bulgaria exceeded the total number in the previous seven years, following the same trend in the other affected EU countries. WNV lineage 2 was confirmed as a cause of the human cases. Overall WNV seroprevalence in human population in the country is 1.5%. Tick-borne encephalitis is very unusual. Only a few cases of TBE have been detected. Overall seroprevalence of 0.6% for TBE virus was found in humans.