West Nile virus seroprevalence in blood donors from Central Anatolia, Turkey.
ABSTRACT West Nile virus (WNV) is a reemerging flavivirus that has displayed a drastic change in epidemiology in the last decade. Data on WNV activity in Turkey are currently limited. This study investigated WNV exposure in blood donors from Central Anatolia, Turkey.
A total of 2516 sera, collected from blood donors at four major branches of the Turkish Red Crescent Middle Anatolia Regional Blood Center, were evaluated by a commercial WNV immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA). Positive and borderline samples were investigated further by a WNV IgG indirect immunofluorescence test (IIFT), IgG ELISAs for tick-borne encephalitis virus and dengue virus, an IgG IIFT for yellow fever virus, and a multi-Flavivirus biochip IgG IIFT. WNV antibody specificity and titer values were determined by plaque reduction neutralization assay. IgG avidity and IgM were determined for confirmed samples. IgM-positive samples were also evaluated by a real-time reverse transcription polymerase chain reaction assay.
Twenty-five samples (25/2516; 0.99%) were found reactive in the WNV ELISA/IIFT assays, and 14 could be confirmed by the plaque reduction neutralization assay (14/2516; 0.56%). All IgGs were of high avidity, and four samples (4/14; 28.6%), which were negative for viral RNA, were IgM positive. Although samples with neutralizing WNV IgGs had strong fluorescence intensity in IIFTs, no correlation between antibody titer values and IIFT intensity or quantitative ELISA results could be found. Three WNV nonreactive samples were positive in the dengue IgG ELISA test; one of these also displayed positive results for dengue virus in the mosaic biochip IIFT and reactivity in yellow fever virus IIFT.
WNV exposure is confirmed in 0.56% of the tested healthy blood donors in Central Anatolia, with evidence for dengue/yellow fever and/or other flaviviral infections. This study is the first to document WNV exposure in individuals from Konya, Yozgat, and Sivas provinces in Central Anatolia, and it also establishes viral activity in Ankara, the capital of Turkey.
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ABSTRACT: In 2010, 47 human cases of West Nile virus (WNV)infection, including 12 laboratory-confirmed and 35 probable cases, were identified in Turkey. These were the first cases detected during routine surveillance.The patients were from 15 provinces, mainly located in the western part of the country. Incidence was 0.19/100,000 with a maximum of 1.39 in Sakarya province.Forty of the total 47 cases showed neuroinvasive manifestation. Median age was 58 years with a range of four to 86. Ten of the patients died. Enhanced surveillance in humans and animals and mosquito control measures were implemented. The WNV infections were included in the national notifiable diseases list as of April 2011. In 2011, three probable and two confirmed cases of WNV infection were diagnosed in provinces where infections had been detected in the previous year, supporting a lower activity than 2010. However,detection of WNV infections in humans in 2010 and 2011 consecutively, may indicate that WNV has become endemic in the western part of Turkey. Field epidemiological studies were undertaken to understand more about the nature of infection in Turkey.Euro surveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 01/2012; 17(21). · 6.15 Impact Factor
Article: Concurrent occurrence of human and equine West Nile virus infections in Central Anatolia, Turkey: the first evidence for circulation of lineage 1 viruses.[show abstract] [hide abstract]
ABSTRACT: BACKGROUND: West Nile fever is an important zoonotic infection caused by West Nile virus (WNV), a member of the Flaviviridae. Previous serological data from Turkey suggest widespread WNV circulation. This report includes cases of human and equine WNV infections occurring concurrently, and manifesting as central nervous system infections, in two neighboring provinces of Central Anatolia, Turkey. A partial phylogenetic analysis of the causative virus is given for the first time. METHODS: The cases were reported in February (horses) and March (human). Symptoms of the disease were similar in the two species, characterized by neurological manifestations suggesting meningoencephalitis. Real-time/nested PCRs and commercial immunoassays and a plaque reduction neutralization assay were employed for the detection of viral RNA and specific antibodies, respectively. RESULTS: WNV RNAs were detected in buffy coat (horses) and cerebrospinal fluid (human) samples. Partial nucleotide sequences of the E-gene coding region revealed that the strains are closely related to viruses of lineage 1, clade 1a. Accompanying equine serosurveillance demonstrated WNV-specific antibodies in 31.6% of the samples. CONCLUSIONS: This is the first report of acute WNV infections caused by lineage 1 strains from Turkey, in concordance with previous reports from some European and North African countries.International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 03/2013; · 2.17 Impact Factor
Article: Multicentre evaluation of central nervous system infections due to Flavi and Phleboviruses in Turkey.[show abstract] [hide abstract]
ABSTRACT: 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. 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. 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. WNV, TBEV and TOSV infections must be considered in cases of meningoencephalitis of unknown etiology in Turkey.The Journal of infection 06/2012; 65(4):343-9. · 4.13 Impact Factor