Nedeni Bilinmeyen Ateş ve Merkezi Sinir Sistemi Enfeksiyonu Olgularında Flavi ve Flebovirusların Araştırılması

Abstract

West Nile virus (WNV), tick-borne encephalitis virus (TBEV) and Toscana virus (TOSV) are among frequently-observed vector-borne viruses causing febrile disease and/or meningitis/encephalitis. The impact of these viruses were investigated at a referral center in Ankara province, Central Anatolia in 2012, where previous reports suggested virus circulation. Serum and/or cerebrospinal fluid samples from 94 individuals were evaluated. Viral nucleic acids in clinical samples were sought via specific and generic PCRs and antibody responses in clinical samples were investigated via commercial indirect immunofluorescence tests (IIFTs). In 8 (8.5%) patients, infections of WNV or TOSV were identified, where previous exposure to these viruses have been revealed in 7 (%7.4) individuals. In 2 patients, neuroinvasive WNV infections were dignosed via viral nucleic acid detection, where the virus strains were characterized as lineage 1 clade 1a via sequencing of the amplicons. TBEV IgG and/or IgM antibodies were detected in 12 cases (12.7%) but antibody specificity could not be confirmed via plaque reduction neutralization test (PRNT). Confirmed and probable TOSV infections were identified in 2 and 4 cases (6.4%), respectively. In one case with detectable TOSV RNA, the infecting isolate was characterized as TOSV genotype A via sequencing of amplicons. A transient pancytopenia was noted in this patient, which is reported for the first time in TOSV infections. In conclusion, circulation of BNV and TOSV was confirmed in our region, with further data indicating virus activity in other regions as well. These viruses must be considered in cases of fever, meningitis and encephalitis of unknown etiology.