Seroprevalence of herpes simplex virus type 1 and type 2 - data from a hospital-based study in Varna, northeastern Bulgaria, 2019-2021.

The purpose of the current study was to describe the prevalence of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in northeastern Bulgaria. From January 2019 to December 2021, we tested 1493 samples for anti-HSV-1 IgG and 817 samples for anti-HSV-2 IgG antibodies in the Virology Laboratory, "St. Marina" University Hospital, Varna, Bulgaria. HSV-1 was considerably more widespread, with an overall seroprevalence of 73.3% (95% CI: 71.0-75.5%), than HSV-2 infection, which showed a seropositive rate of 10.0% (95% CI: 8.1-12.4%). Age was the most significant risk factor for both infections, while gender had no role in herpes simplex seropositivity.

Dealing with inconclusive SARS-CoV-2 PCR samples-Our experience.

PURPOSE: Early confirmation of SARS-CoV-2 is a key point in the timely management of infected patients and contact persons. Routine diagnostics of COVID-19 cases relies on RT-PCR detection of two or three unique sequences of the virus. A serious problem for the laboratories is how to interpret inconclusive samples which are positive for only one of the SARS-CoV-2 specific genes. MATERIALS AND METHODS: A total of 16364 naso-oropharyngeal swabs were collected and tested with SARS-CoV-2 Real-TM kit (Sacace Biotechnologies, Italy) between May and September 2020. We retrospectively analyzed their amplification plots to determine the number of inconclusive samples. We also reviewed the medical records to summarize the patient's COVID-19 testing history and basic demographic characteristics. RESULTS: We obtained 136 (0.8%) inconclusive samples with amplification signal only for the N-gene. Thirty-nine of the samples were excluded from further analysis as no additional data were available for them. Of the rest of the samples, the majority- 48% (95% CI 38-59%) had a previous history of SARS-CoV-2 positivity, 14% (95% CI 8-23%)-a subsequent history of positivity and 37% (95% CI 28-48%) were considered as false positive. CONCLUSION: A substantial proportion of the inconclusive results should be considered as positive samples at the beginning or the end of the infection. However, the number of false-positive results is also significant and each patient's result should be analyzed separately following the clinical symptoms and epidemiological data.

Detection of EBV DNA in Non-Hodgkin Lymphoma Patients in Bulgaria.

Epstein-Barr virus is the first human oncogenic virus associated with a broad range of different malignant diseases but its role in non-Hodgkin lymphomas (NHL) development still needs to be fully understood. High expression levels of EBV major genes are found in NHL tumor cells and free viral DNA circulates in the plasma of such individuals. In the current study we detected EBV DNA levels in plasma samples from NHL patients in order to validate its significance as a laboratory marker for disease monitoring. We investigated a cohort of 52 patients diagnosed with NHL in The University Hospital "St. Marina" Varna, Bulgaria. Viral DNA was extracted from single plasma samples using Kit Ribo Virus (Sacace Biotechnologies S.r.l., Como, Italy) and amplified with EBV Real-TM Quant (Sacace Biotechnologies S.r.l., Como, Italy). Plasma samples of the same patients were tested for presence of EBV VCA IgM/IgG antibodies with indirect ELISA tests (Euroimmun, Luebeck, Germany). We found 15.4% (95% CI 6.9-28.1%, n = 8) of the samples from NHL patients to be positive in quantitative PCR (range 674-221,333 copies/ml). The diffuse large B cell lymphomas and peripheral T cell lymphomas were most often associated (although not statistically significant, p = 0.167) with detectable plasma EBV DNA levels. To our knowledge, this is the first study about the role of EBV in NHL development in Bulgaria. The results we have obtained should stimulate new, larger investigations to apply the quantitative PCR technique in the routine laboratory EBV diagnosis.

Seroprevalence of hepatitis B among pregnant women in Varna Region, Bulgaria.

The aim of the present study was to assess the prevalence of hepatitis B surface antigen among pregnant women in Varna Region, Bulgaria. During the period 2009-2013, an average prevalence of 2.26% (95%CI 1.75, 2.91) was measured in a total number of 2,700 samples. Analysis demonstrated that rural residence and minority ethnic origin are important risk factors for hepatitis B infection among pregnant women with hazard ratios of 2.40 (95%CI 1.46, 3.94), and 2.43 (95%CI 1.46, 4.05) when compared with urban residence and ethnic majority origin, respectively. J. Med. Virol. 88:2012-2015, 2016. © 2016 Wiley Periodicals, Inc.

Seroprevalence of Syphilis among Pregnant Women in the Varna Region (Bulgaria).

Syphilis is a sexually transmitted disease with continuously rising rates among European countries. The vertical (mother to child) transmission is an important way of dissemination, often leading to stillbirth and permanent impairment of the newborn. We present a retrospective cross-sectional analysis of 2702 pregnant women tested for syphilis seropositivity. During the study period (2009-2013) non-specific and specific treponemal antibodies were detected in 15 pregnant women (0.56% of sample size with 95% confidence interval (CI) 0.28-0.84). Our results showed a lack of correlation between syphilis seropositivity and age, ethnic origin, or pregnancy trimester of the mother. The only factor found to influence syphilis seropositivity was the mother's place of residence - rural inhabitants had significantly higher risk for syphilis infection when compared to urban inhabitants, with a seropositive proportion of 1.08% versus 0.36%, respectively.