[Prevalence of anti-HCV antibodies among adults in Poland--results of cross-sectional study in general population]

According to WHO data, there are 130-170 million hepatitis C virus (HCV) infected persons world-wide. Data on the prevalence of HCV infection in Poland is still insufficient.

OBJECTIVE

The aim of study was to determine the prevalence of HCV infection in the general population in Poland and to characterize the positive predictive value of the ELISA screening test.

MATERIAL AND METHODS

A total of 4822 persons aged 18+ and hospitalized on surgical, trauma-orthopedic and laryngological wards in Lubelskie, Mazowieckie, Swietokrzyskie, Warminsko-Mazurskie and Wielkopolskie voivodeships were enrolled into the study. The scheme of cluster sampling was applied. Hospitals wards were selected randomly from Health Care Units Registers. Detection of anti-HCV antibodies was performed using the 4th generation qualitative ELISA test (Dia Sorin, Murex). All positives samples were subject to further testing by Western Blot and retested by ELISA. According to ELISA test producers instructions, samples that were repeatedly reactive were considered as positive (reactive). Using the confirmation test (Western Blot), antibodies directed against specific antigens of HCV (C1, C2, E2, NS3, NS4, NS5) were determined. To determine the prevalence of HCV infections, repeatedly reactive ELISA samples, confirmed by Western Blot (WB) were used. In order to estimate the prevalence of anti-HCV antibodies in general population, indirect standardization according to age groups (<30, 30-49, 50-69, >or =70), gender and place of residence (urban/rural) was employed.

RESULTS

Initially positive ELISA test results were obtained in 92/4822 patients (1.91%) and repeatedly positive results--in 46/4822 patients (0.95%). The presence of anti-HCV was confirmed by WB in 54/4822 (1.12%), which constituted 58.7% (54/92) of single-reactive samples and 95.7% (44/46) of double-reactive samples. The positive results of Western Blot were obtained for 10 samples, which were not repeatedly reactive in ELISA test. The standardized prevalence of anti-HCV antibodies amounted to 0.86% (95% CI: 0.59-1.14%). Positive predictive value for a single reactive ELISA test accounted for 47.8% (95% CI: 37.4-58.2%).

CONCLUSIONS

Given the low predictive value of the single-positive ELISA, performance of repeated ELISA tests, even for epidemiological purpose, would be recommended.

Seroprevalence of Lyme disease and genospecies of Borrelia burgdorferi sensu lato in patients diagnosed with borreliosis in the Province of Warmia-Masuria in north-eastern Poland

Between 2009-2010, a group of 259 patients suspected of contracting Lyme disease were examined in the Provincial Sanitary-Epidemiological Station in Olsztyn for the presence of IgM and IgG against specific Borrelia burgdorferi sensu lato (s.l.) genospecies antigens by immunoblot. A total of 27.4% and 29.0% of the blood serum samples showed positive and uncertain results for IgM and IgG antibodies. The majority of positive and uncertain results were found in patients aged 30-40 years (30%) for IgM, and people aged 50 and over (35.8%) for IgG. Significantly more positive results for IgG were found in males (40.2%) then females (19.7%). In both groups, similar proportions of positive results for IgM anti-Borrelia were recorded (26.1% of females and 29% of males. In 71.5% of patients, IgM against flagellin protein (p41) of B. burgdorferi sensu stricto (s.s.) was found. For IgG, the most frequently detected antibodies were found against the p41 protein of B. burgdorferi s.s. (64.8%) and the recombinant variable surface antigens (VlsE) (49%). Among all the analysed antigens those of B. burgdorferi s.s. were the most frequent cause of immunological reaction, followed by antigens of B. afzelii and B. garinii. Reaction to antigens of B. spielmanii was rarely detected.

[Serological confirmation of the prevalence of tick-borne encephalitis virus among patients with neurological infections in the Warmia-Masuria province in 2006-2010]

The aim of the study was to analyze of tick-borne encephalitis (TBE) in the Warmia-Masuria province on the basis of serological testing of 878 patients with symptoms of neurological infections, diagnosed in 2006-2010 in the Voivodeship Sanitary-Epidemiological Station in Olsztyn. Specific IgM and IgG antibodies against the TBE virus were detected in serum and cerebrospinal fluid samples by ELISA method. Percentage of persons with serologically confirmed TBE was 15.5%. This confirms contact with TBE virus and its role as the suspected cause of neurological infections in patients in the Warmia-Masuria province. Men and people over 46 years of age were more commonly seropositive. Among examined patients the percentage of seropositive men was 18.1% and the proportion of seropositive women was - 12.9%. Most positive results were found in patients between 46 and 50 years of age (20.7%) and in those aged 56-60 years (19.5%). Seasonal patterns were detected, with highest proportion of seropositive results in July, August and October.