Hayriye Kirkoyun Uysal

Background/Objectives: Hepatitis B (HBV) and hepatitis C (HCV) coinfection leads to the progression of liver disease and results in clinically serious outcomes. Continuous monitoring of epidemiological data is crucial for managing the regional disease burden. This study investigates the current seroprevalence of HBV and HCV, the prevalence of coinfection, and the rates of active replication in Istanbul. Methods: This retrospective analysis included 7131 patients evaluated at the Infectious Diseases and Gastroenterohepatology clinics between 2021 and 2025. Initial serological screening for viral markers was performed using routine chemiluminescent immunoassays. Active viral replication was subsequently confirmed and quantified via real-time polymerase chain reaction (PCR). Results: Active HBV replication was significantly more frequent among patients in the Gastroenterohepatology clinic (20.47%) compared to those in Infectious Diseases (5.36%). Active HCV infections were rare in both departments (0.25% and 0.04%, respectively). Simultaneous HBV and HCV coinfection was detected in only 17 patients (0.24%). Demographic evaluation demonstrated that HBV marker positivity was more prevalent in male patients and individuals over 40 years of age. Conclusions: HBV seroprevalence remains substantially higher than HCV in this cohort. The high rate of active HBV replication in gastroenterohepatology settings indicates a concentrated burden of active disease in these specialized clinics. These distribution patterns emphasize the necessity of routine, targeted HBV screening for older male demographics to facilitate early clinical intervention.

This study aimed to assess the humoral immune response following administration of a BNT162b2 mRNA COVID‐19 booster dose and to evaluate its association with the development of SARS‐CoV‐2 infection after vaccination. Between July 2021 and February 2022, serum samples were collected from 313 individuals 28 days after receiving a COVID‐19 booster dose. Quantitative SARS‐CoV‐2 IgG antibodies directed against the receptor‐binding domain (RBD) of the spike protein were measured using a chemiluminescent microparticle immunoassay. Neutralizing antibody activity, defined as inhibition of the RBD–ACE2 interaction, was evaluated semi‐quantitatively by a competitive ELISA. Participants were followed for 6 months after the final dose to identify confirmed SARS‐CoV‐2 infections. The cohort included 97 males (31%) and 216 females (69%), with a mean age of 39.43 years. The median SARS‐CoV‐2 IgG antibody level at day 28 was 7713.3 AU/mL, and the median neutralizing antibody inhibition rate was 99.2%. Antibody levels were not significantly associated with age or comorbidities. Booster vaccination induced a strong humoral immune response in all participants. However, the occurrence of post‐vaccination infections despite high antibody levels suggests immune escape by emerging variants. While vaccines may not fully prevent infection, they provide substantial protection against severe disease and mortality.

The human gut microbiome is essential for immune regulation and mucosal homeostasis, functions that are profoundly disrupted during HIV infection. Early viral replication in the gut-associated lymphoid tissue (GALT) triggers a self-reinforcing cycle of CD4⁺ T-cell depletion, epithelial barrier breakdown, and increased microbial translocation. This persistent immune activation continues even under effective antiretroviral therapy (ART). A growing body of evidence indicates that HIV infection is consistently associated with alterations in gut microbial communities. This dysbiosis is typically characterized by fewer beneficial butyrate-producing commensal bacteria and an enrichment of pro-inflammatory microbial taxa. It also involves disturbances in key microbial metabolites, including short-chain fatty acids (SCFAs) and tryptophan catabolites. Such changes not only exacerbate systemic inflammation but may also contribute to incomplete immune reconstitution and the persistence of latent viral reservoirs despite long-term ART. In this review, we summarize current knowledge of microbiome–HIV interactions, with particular emphasis on the mechanisms through which gut dysbiosis contributes to immune dysfunction and viral persistence. We discuss recent advances in multi-omics technologies, as well as experimental systems such as gnotobiotic and humanized mouse models and intestinal organoid platforms that are helping to elucidate these complex interactions. Furthermore, we evaluate emerging microbiome-targeted interventions—including probiotics, prebiotics, fecal microbiota transplantation, and engineered bacterial therapeutics—and consider their potential role as adjunctive strategies in HIV treatment and cure research. By integrating microbiological, immunological, and clinical perspectives, this review highlights key knowledge gaps and outlines future research directions aimed at harnessing the gut microbiome as a novel therapeutic avenue in HIV management and eradication.

Human Metapneumovirus (HMPV) is a leading viral cause of respiratory infections worldwide, particularly affecting children, elderly adults, and immunocompromised individuals. Since its discovery in 2001, HMPV has been recognized as a significant pathogen responsible for both upper and lower respiratory tract infections, often manifesting as bronchiolitis, pneumonia, and wheezing in infants, as well as acute respiratory distress syndrome (ARDS) in older adults and immunocompromised patients. Although it shares clinical features with Respiratory Syncytial Virus (RSV), HMPV is genetically distinct, posing unique challenges for diagnosis, treatment, and prevention. This review provides a comprehensive analysis of HMPV, focusing on its virus structure, genetic makeup, taxonomy, clinical features, and epidemiology. It also explores advances in diagnosis, prevention, and therapeutic strategies, highlighting the urgent need for continued research to address the global burden of HMPV.

Cytomegalovirus (CMV) remains a major opportunistic pathogen in individuals with HIV. The aim of this study was to investigate the seroprevalence and reactivation rates of CMV among HIV-positive individuals. A total of 300 people with HIV presenting to the Istanbul Faculty of Medicine were enrolled. Serological assessments were performed using enzyme-linked immunosorbent assay (ELISA), while molecular analyses were conducted through PCR-based methods. Sociodemographic and clinical characteristics of the patients were also evaluated. Of the participants, 90% were male, with an age range of 18–76 years. Serological testing demonstrated CMV IgG positivity in 292 patients (97.3%) and CMV IgM positivity in 11 patients (4.07%). CMV DNA was detected in 91 patients (30.3%) by molecular assays, with viral loads ranging from p < 0.05) and was associated with lower CD4+ T lymphocyte counts. CMV disease was identified in 50 patients (16.7%), with organ involvement (64%) representing the most common clinical manifestation. CMV seropositivity is remarkably high in HIV-positive individuals, and reactivation rates are increased, particularly in older patients and those with advanced immunosuppression. These findings underscore the clinical relevance of routine CMV surveillance in the management of HIV infection.

Aims: Congenital cytomegalovirus (cCMV) infection is a major cause of prenatal morbidity, frequently associated with central nervous system (CNS) involvement. This study aimed to determine the frequency of CMV DNA in amniotic fluid (AF) samples obtained from pregnancies with high-risk ultrasound findings suggestive of prenatal CMV infection during the second trimester and to evaluate the associated prenatal findings.Methods: This retrospective study included 238 pregnant women who underwent amniocentesis between January 2023 and November 2025 due to high-risk ultrasound findings identified by experienced perinatologists. CMV DNA in AF samples was detected using Real-Time PCR (RT-PCR). Maternal CMV IgG and IgM serological results were obtained from patient records. Prenatal ultrasound findings, serological data, and molecular test results were analyzed statistically. Results: CMV DNA was detected in 10 of 238 AF samples (4.20%; 95% confidence interval: 1.7-6.8%). In cases with CMV DNA positivity, prenatal ultrasound findings predominantly involved CNS anomalies (80%). CMV IgG positivity was observed in all CMV DNA-positive cases, while CMV IgM positivity was not detected in any patient. Conclusion: The strong association between CNS-predominant ultrasound anomalies and CMV DNA positivity underscores the diagnostic value of CMV DNA PCR testing in AF samples for prenatal CMV infection. These findings support the use of molecular diagnostic methods alongside ultrasonographic evaluation, as maternal serological screening alone may be insufficient for accurate prenatal CMV diagnosis.

(1) Background: This study investigated the presence of human papillomavirus (HPV), HPV genotypes, Epstein–Barr virus (EBV), cytomegalovirus (CMV) and herpes simplex virus (HSV) in patients with Head and Neck Cancer (HNC) at both molecular and serological levels. (2) Methods Fifty patients with histopathologically confirmed HNC who were admitted to the Department of Otorhinolaryngology, Istanbul Faculty of Medicine. Viral DNA was detected using quantitative real-time PCR, and serological IgM and IgG antibodies were analyzed using the CMIA method; (3) Results: In blood samples, CMV and HSV DNA were not detected, whereas EBV DNA was identified in 2% and HPV DNA in 4% of patients. In tumor tissues, CMV DNA was detected in 8%, EBV DNA in 10%, and HPV DNA in 6%; HSV DNA is 6%. HPV genotypes 18, 45, and 69 were found in tissue samples. Serologically, IgG positivity for CMV, EBV, and HSV-1 exceeded 90%, whereas IgM positivity was low and not statistically significant; (4) Conclusions: HPV, EBV, and CMV DNA were detected at low frequencies in patients with HNC, while HSV DNA was absent. These findings underline the need for larger multi-center studies and support the consideration of routine viral screening, particularly for HPV, in specific tumor subtypes.

Aims: This study retrospectively evaluates the serological (CMV IgM and IgG) and molecular (CMV DNA PCR) test results of patients admitted to İstanbul Faculty of Medicine Hospital between 2021 and 2023 due to suspected cytomegalovirus (CMV) infection. The aim is to assess the diagnostic value of combining serological and molecular methods and to analyze CMV positivity across age and gender groups. Methods: This cross-sectional observational study included 1.649 patients who underwent CMV testing (CMV IgM, CMV IgG, and/or CMV DNA PCR) at the Medical Microbiology Laboratory of İstanbul Faculty of Medicine between January 1, 2021, and December 31, 2023. Serological tests were performed using ELISA (Vircell, Spain), and CMV DNA was quantified using real time PCR (QIAsymphony/Artus CMV QS-RGQ and cobas® 6800). Data were anonymized and analyzed statistically using SPSS v26.0. Mann-Whitney U, Chi-square, McNemar, and ROC tests were applied; p0.05), CMV DNA positivity varied significantly across age groups (p

Background/aim: This study investigates the relationship between fear of COVID-19, measured using the Fear of COVID-19 Scale (FCV-19S), and the hygiene behaviors of secondary school students, assessed with the Hygiene Behavior Scale (HBS). Materials and methods: Included in this cross-sectional study were 206 secondary school students. The study data were analyzed using multivariate linear regression. Results: No relationship was found between the fear of COVID-19 scale (FCV-19S) score of the student sample and the mean total HBS and subdimension values (p > 0.05). It was noted that positive hygiene behaviors decreased as the scale score increased. Students with retired mothers scored 4.463 units higher in the personal hygiene subdimension than those whose mothers were housewives, while the students whose mothers were in blue-collar roles scored 4.868 units higher on the personal hygiene subdimension than those whose mothers were housewives (p < 0.05). The students whose mothers were retired scored 3.845 units higher on the hand-washing subdimension than those whose mothers were housewives (p < 0.05), while those with retired mothers scored 4.052 units higher on the food hygiene subdimension than those whose mothers were housewives (p < 0.05). Students whose mothers were retired scored 12.361 units higher on the HBS than those whose mothers were housewives, while those whose mothers were blue-collar workers scored 7.884 units higher on the HBS than those whose mothers were housewives (p < 0.05). The total mean HBS score of the sample was 48.25 ± 14.41, while the total mean FCV-19S score was 15.18 ± 7.69. Conclusion: No significant relationship was noted between the Fear of COVID-19 Scale (FCV-19S) scores and hygiene behaviors of secondary school students. Significantly higher total and subdimension HBS scores were noted in students whose mothers were retired or employed than in those whose mothers were housewives. These findings suggest that maternal employment status may play an influential role in the hygiene behaviors of students.

This study aimed to investigate prolonged severe acute respiratory syndrome coronavirus-2 polymerase chain reaction (PCR) positivity in hospitalized COVID-19 patients and evaluate the diagnostic performance of rapid antigen tests (RAgT) compared to real-time reverse transcription-PCR (RT-PCR). A prospective single-center study included 82 patients with prolonged PCR positivity (≥28 days). Serial RT-PCR and RAgT were performed at days 7 to 10, 14 to 20, and 28 to 30 post-diagnosis. Clinical data, comorbidities, and laboratory parameters (inflammatory markers, hematological, and biochemical profiles) were analyzed. Statistical analyses included sensitivity, specificity, Cohen Kappa, and receiver operating characteristic curve assessment. RAgT demonstrated 100% sensitivity and 74% specificity relative to RT-PCR, with strong agreement (Cohen κ = 0.803, P* < .001). Inflammatory markers were elevated: C-reactive protein (median 3.55 mg/L), ferritin (510 µg/L), and D-dimer (1400 ng/mL). Comorbidities were present in 62% of patients, primarily hypertension (17%) and diabetes mellitus (15%). Female patients exhibited higher inflammatory markers (C-reactive protein, fibrinogen, and lactate dehydrogenase) and anemia prevalence. Receiver operating characteristic analysis revealed excellent discriminative performance (area under the curve = 0.99). RAgT showed high sensitivity in detecting severe acute respiratory syndrome coronavirus-2 among patients with prolonged PCR positivity, suggesting potential utility in differentiating active infection from residual viral RNA. Persistent PCR positivity may correlate with noninfectious viral shedding, and RAgT could complement RT-PCR in clinical decision-making, particularly in resource-limited settings. Further multicenter studies are needed to validate these findings and assess the impact of viral variants.