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Objectives: Flavi- and Phleboviruses associated with central nervous system (CNS) infections including West Nile Virus (WNV), Tick-borne Encephalitis Virus (TBEV) and Toscana Virus (TOSV) cause significant morbidity and mortality in humans. In this study, the impact of these agents have been investigated in CNS infections at referral hospitals in two provinces in Turkey, where circulation of these viruses have previously been recognized., Methods: In the study, 258 samples from 126 individuals from Ankara and 113 samples from 108 individuals from Izmir provinces collected in 2010 were included. Viral RNAs were investigated by multiple genus and strain specific primers. Commercial serological assays were employed in screening and reactive results were evaluated with additional assays and by plaque reduction neutralization assay., Results: Two cases of WNV CNS infections, 14 cases of TOSV infections and one TBEV-exposed individual were identified via serological testing. WNV infections in 61 and 56-year old individuals from Ankara presented with fever and encephalitis without skin rash and residual neurologic damage. TOSV-associated cases from both provinces mainly displayed signs of meningitis. TOSV exposure was documented for the first time from Izmir., Conclusions: WNV, TBEV and TOSV infections must be considered in cases of meningoencephalitis of unknown etiology in Turkey., (Copyright © 2012 The British Infection Association. Published by Elsevier Ltd. All rights reserved.)

Tick-borne encephalitis virus (TBEV) is the aetiological agent of tick-borne encephalitis (TBE), a potentially fatal central nervous system infection of humans. TBE is endemic in many areas of Europe and Asia; however, very scarce data on TBEV activity are available from Turkey. We aimed to identify TBEV exposure in healthy blood donors and the impact of TBEV in central nervous system infections in Central/Northern Anatolia. Two-thousand four hundred and fifty four sera, collected from blood donors at Ankara, Konya, Eskişehir and Zonguldak branches of the Turkish Red Crescent Middle Anatolia Regional Blood Center, were analysed for TBEV serosurveillance. Paired serum and cerebrospinal fluid samples from 108 patients with the diagnosis of aseptic meningitis/encephalitis of unknown aetiology were also evaluated to identify TBE and neuroborreliosis cases. Commercial enzyme-linked immunosorbent assays and indirect immunofluorescence tests were employed for antibody detection. Forty-seven donor samples (1.9%) were reactive for TBEV IgG. In 25 persons with IgG reactivity (53.1%), risk factors for tick-borne infections were revealed. One sample from Zonguldak province (1/198; 0.5%) in the Black Sea region of Turkey was confirmed to possess neutralizing antibodies via plaque reduction neutralization test. TBEV IgM was detected in 9.2% (8/108) of the patients. IgM was accompanied by IgG reactivity in two persons where, in one, recent history of a tick bite was also identified. Intrathecal antibody production for TBEV could not be demonstrated. No evidence for Borrelia infections could be found. Confirmed exposure to TBEV and/or an antigenically similar tick-borne flavivirus is documented for the first time in blood donors in Zonguldak in Northern Anatolia. Probable cases of TBE have also been identified from Central Anatolia. The epidemiology of TBEV activity in Turkey needs to be assessed and benefits of vaccination for general population, risk groups or travellers must be considered., (© 2010 Blackwell Verlag GmbH.)

Arthropod-borne viral infections have recently gained considerable attention and importance as re-emerging infections in a global scale. West Nile Virus (WNV), a member of Flaviviridae, is an enveloped positive strand RNA virus that is usually transmitted to humans by the bite of Culicine mosquitoes. Although the majority of the human infections are asymptomatic, WNV may also cause febrile and neuro-invasive diseases. Seroprevalence data from Turkey indicate that WNV activity is present in Central Anatolia. In this study performed at Hacettepe University Hospital, paired serum and cerebrospinal fluid (CSF) samples from 87 adult patients with the preliminary diagnosis of aseptic meningitis/encephalitis of unknown etiology were evaluated retrospectively to identify WNV-related syndromes. Bacterial, fungal and mycobacterial cultures yielded negative results and Mycobacterium tuberculosis and Herpes simplex virus nucleic acid tests were also negative for the selected patients. Commercial enzyme-linked immunosorbent assay (ELISA)s and indirect immunofluorescence test (IIFT)s were employed for WNV IgM and IgG antibody detection (Anti-WNV Virus IgG/IgM ELISA, Anti-WNV Virus IgG/IgM IIFT; Euroimmun, Germany). Additional ELISA/IIFT assays were further performed for WNV antibody reactive samples to identify cross-reactions and/or infections with other flaviviruses and phleboviruses. All WNV antibody positive samples were also evaluated by a WNV real-time reverse-transcription polymerase chain reaction (RT-PCR) assay. WNV IgM and IgG antibodies were detected in %9.2 (8/87) and 3.4% (3/87) of the serum samples, respectively. All IgG reactive samples were negative for IgM. All sera with WNV antibody reactivity (n = 11) and the corresponding CSF samples were negative for viral RNA via RT-PCR. In 5 of the 8 WNV IgM positive subjects, sandfly fever virus IgM antibodies were detected, which was also accompanied by Dengue virus IgM positivity in one sample. In another case, intrathecal antibody synthesis against measles virus was demonstrated. Two cases (2/87; 2.3%) with WNV IgM positivity as the only serologic marker were identified as probable WNV infections and clinical features were discussed. In conclusion, in order to fully understand the impact of WNV and/or other flavivirus infections in Turkey, epidemiology and ecological features of these agents need to established.