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.

Congenital Cytomegalovirus Infection - Lessons from a Clinical Case.

BACKGROUND: Cytomegalovirus (CMV) is a worldwide spread herpes virus that establishes a latent infection after the primary infection. It becomes a major problem in immunocompromised patients and in cases of primary or reactivated infection during pregnancy. CMV is the most common congenital infection and is the leading infectious cause of sensoneural deafness and cerebral mental retardation. AIM: Тo raise the attention to the discordance in our knowledge of cCMV infection and the implementation of the knowledge in prac-tice. MATERIALS AND METHODS: CMV-DNA was extracted from saliva and plasma samples according to the protocol of DNA-Sorb-A, Sacace, Biotechnologies, Italy. Polymerase chain reaction (PCR) was performed using a commercial kit based on the Taq-man principle: Quantitative RT-PCR for CMV-DNA detection (Sacace, Biotechnologies, Italy). The linear range of the CMV Real-TM Quant PCR test is 500-10000000 copies/ml, and the reported sensitivity is 400 copies/ml. RESULTS: The infant was born with clinical manifestations involving development of hepatosplenomegaly, chorioretinitis, anemia, mi-crocephaly and simultaneous dilatation of the brain ventricles. CMV infection was confirmed using modern PCR studies. CONCLUSIONS: This case highlights the need for specific virological/PCR tests to be performed for all children with the least suspected congenital infection, especially when there is an option of a specific treatment.

Hepatitis C virus genotype analysis in patients with chronic hepatitis in North Eastern Bulgaria.

Background: The main objective of this study was to analyse the spread of hepatitis C virus (HCV) genotype in patients with chronic liver disease; commenting on the molecular characterization of HCV and gender and age in Varna, Bulgaria. Across Europe and the world, HCV is a significant economic concern and public health crisis. Defined by genotype variations, HCV is the leading cause of chronic liver disease, liver related morbidity, and mortality worldwide. Active examination for asymptomatic patients is essential, initiating early treatment aimed at the specific HCV genotype, effective outcomes, and reducing transmission and mortality in Bulgaria. Methods and materials: Nucleic acid extraction and amplification were performed with commercially available test kits on 115 patients blood samples collected from March 2018 to October 2018. Male (n = 58) (50.43%, 95% CI = 41.29%-59.57%) and female (n = 57) (49.57%, 95% CI = 41.29%-59.57%) samples were equally distributed (mean age = 51.4 years; SD = ±16.5 years; range = 17-87 years old). Results: Genotype 1b predominated (73%, 95% CI = 64.89%-81.11%), followed by high prevalence of 1a (13.9%, 95% CI = 7.58%-20.22%) and 3 genotypes (11.3%, 95% CI = 5.51%-17.09%). Genotypes 2 and 4 were equally the least prevalent (0.9%, 95% CI = -0.83%-2.63%). In genotype 1b, 60.7% were women and 39.3% were men; in genotype 1a, 25% were women and 75% were men; and in genotype 3, only 7.7% were women and 92.3% were men. Males were most prevalent in genotypes 1a (75%) and 3 (92.3%), while women were most prevalent in genotype 1b (60.7%). Conclusions: HCV genotype lb is the predominant variant within the epidemiological pattern of HCV genotypes in patients with chronic liver diseases in North Eastern Bulgaria.

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.

The Role of Cytomegalovirus in Congenital and Early Postnatal Infections in Northeastern Bulgaria.

BACKGROUND: Human cytomegalovirus is a ubiquitous, large enveloped DNA ß-herpesvirus that, like other herpesviruses, establishes lifelong latency following primary infection. It is the most frequent cause of congenital, neonatal and early postnatal infections with long lasting sequelae. AIM: The aim of the present study was to assess the prevalence of cytomegalovirus among a cohort of newborns and 1-3-month-old children with neurological symptoms, physical retardation, prolonged jaundice, thrombocytopenic purpura and other disabilities. MATERIALS AND METHODS: The study was a retrospective cross-sectional analysis of serological screening data for detection of specific anti-cytomegalovirus IgM and IgG in children from Northeastern Bulgaria. RESULTS: Between 2003 and 2015, average prevalences of 18.8% (95% CI: 15.4 to 22.2) for anti-CMV IgM antibodies (suggesting acute infection) and 84.7% (95% CI: 81.6 to 87.8) for anti-CMV IgG antibodies were measured in a total number of 517 samples. The prevalence rate of anti-CMV IgM in 1-3-month-old children was 4-fold higher than that in newborns [25.8% (95% CI: 21.1 to 30.5) and 6.4% (95% CI: 2.9 to 9.9, respectively]. In contrast, no significant difference was found for anti- CMV IgG positivity between newborns and 1-3-month-old infants (84% and 85%, respectively). CONCLUSIONS: The data obtained strongly encourage screening of pregnant women for anti-CMV IgG and IgM to avoid transmission of the infection and severe complications of congenital infection.