Disease severity, previous medications, immunosuppresive agents could affect the antibody response against SARS-CoV-2. We aimed to analyze variables affecting the humoral response to SARS-CoV-2. In this prospective cohort study, we included adult patients who recovered from COVID-19 and were admitted to COVID-19 follow-up unit. We defined 8 patient groups in accordance with the results of thorax CT, SARS-CoV-2 PCR test, and tocilizumab or anakinra use during active disease. Anti-S IgG antibodies were determined by ELISA in serum samples. Anti-S positive and negative cases were compared. A total of 518 patients were included in the study. SARS-CoV-2 IgG antibodies were positive in 82.8% of patients. SARS-CoV-2 PCR positivity, extent of lung involvement on CT, and time to antibody testing were independently associated with antibody positivity. Tocilizumab, anakinra or prednisolone use was not a factor affecting the antibody response. The rate of antibody response and sample/CO values among antibody positive patients showed a linear relationship with the extent of lung involvement on CT. The use of tocilizumab, anakinra, and prednisolone for COVID-19 did not affect the antibody response against SARS-CoV-2. The main driver of antibody response among patients with COVID-19 was the extent of pulmonary involvement on CT.

Infections with influenza A virus cannot be clinically differentiated from infections caused by influenza B virus or other respiratory viruses. Additionally, although antiviral treatment is available for influenza A virus, it is not effective for the other viruses and must be initiated early in the course of disease for it to be effective. For these reasons, there is a need for a rapid, accurate diagnostic test for use in physicians’ offices at the time patients are seen. We report the first field performance of BD Veritor™ System for Rapid Detection of Flu A + B test compared to real time PCR. The performance of this test was compared to real time PCR performed in the Istanbul University Influenza Reference Laboratory. A single-blinded cross sectional study was conducted in nine different family medicine centers in Istanbul, Turkey between 01 November 2014 and 01 May 2015. For every patient, two specimens were collected, one for real time PCR and one for the Veritor test. Specimens for the Veritor test were immediately tested at the participating clinic according to the manufacturer’s instructions. The specimens for real time PCR were transferred to the reference laboratory. A total of 238 persons were included in the study: 72 (30 %) of the patients included in the study were below 19 years old and accepted as childhood group. Mean age of adults was 42.4 and children 10.2 years. A total of 122 patients out of 238 were positive for influenza. The clinical sensitivity and specificity of the Veritor test in all age groups was determined to be 80 and 94 %, respectively. Positive predictive value was 93 % and the negative one was 81 %. Field performance of the rapid influenza test was high and found to be useful with respect to rational antiviral use, avoiding unnecessary antibiotic usage and the management of cases by the family physicians.

Human pegivirus (HPgV) is transmitted through sexual or parenteral exposure and is common among patients receiving blood products. HPgV is associated with lower levels of human immunodeficiency virus (HIV) RNA and better survival among HIV-infected patients. This study aimed to investigate the prevalence of HPgV and determine its subtypes in HIV-infected individuals living in Istanbul, which has the highest rate of HIV infection in Türkiye. Total RNA extraction from plasma, cDNA synthesis, and nested PCR were performed for HPgV on plasma samples taken from 351 HIV-1-infected patients. The HPgV viral load was quantified on HPgV-positive samples. HPgV genotyping was performed by sequencing the corresponding amplicons. In the present study, the overall prevalence of HPgV RNA in HIV-infected patients was 27.3%. HPgV subtypes 1, 2a, and 2b were found, with subtype 2a being the most frequent (91.6%). Statistical analysis of HIV-1 viral load on HPgV viral load showed an opposing correlation between HIV-1 and HPgV loads. In conclusion, these data show that HPgV infection is common among HIV-positive individuals in Istanbul, Türkiye. Further comprehensive studies are needed to clarify both the cellular and molecular pathways of these two infections and to provide more information on the effect of HPgV on the course of the disease in HIV-infected individuals.

The frequency of bacterial factors causing central nervous system infections has decreased as a result of the development of our national immunization program. In this study, it is aimed to obtain the data of our local surveillance by defining the viral etiology in cases diagnosed with meningoencephalitis for 1 year. Previously healhty 186 children, who applied with findings suggesting viral meningoencephalitis to 8 different tertiary health centers between August 2018 and August 2019, in Istanbul, were included. The cerebrospinal fluid (CSF) sample was evaluated by polymerase chain reaction. The M:F ratio was 1.24 in the patient group, whose age ranged from 1 to 216 months (mean 40.2 ± 48.7). Viral factor was detected in 26.8%. Enterovirus was the most common agent (24%) and followed by Adenovirus (22%) and HHV type 6 (22%). In the rest of the samples revealed HHV type 7 (10%), EBV (6%), CMV (6%), HSV type 1 (6%), Parvovirus (4%) and VZV (2%). The most common symptoms were fever (79%) and convulsions (45.7%). Antibiotherapy and antiviral therapy was started 48.6% and 4% respectively. Mortality and sequela rate resulted 0.53% and 3.7%, respectively. This highlights the importance of monitoring trends in encephalitis in Turkey with aview to improving pathogen diagnosis for encephalitis and rapidly identifying novel emerging encephalitis-causing pathogens that demand public health action especially in national immunisation programme.

Among sexually transmitted diseases, HIV causes very serious clinical manifestations that can lead to death. As a result, millions of people have to live with this problem that threatens their health. The virus attacks the immune system of the host, especially CD4+ T lymphocytes, causing the suppression of the immune system. CD4, CD8 counts, and HIV RNA viral loads are monitored in HIV-infected patients with antiretroviral treatment, and CD4 counts play an important role in determining the effectiveness of the treatment. Despite the advances in treatment in the present day, opportunistic infections are the main cause of morbidity and mortality in these patients, and the evaluation of immunological parameters is valuable for the prognosis of the disease in this process. In the present study, the purpose was to investigate the opportunistic infections faced by naive HIV-positive patients who applied to our laboratory and were diagnosed between 2019 and 2022 during their one-year treatment period, and the correlation of the immunological parameters was also evaluated retrospectively using the hospital automation system and laboratory data. A total of 107 opportunistic causative microorganisms were identified in 87 of the 230 HIV-positive patients over one year. T. pallidum was detected in 43 (18.6%) of these patients, Cytomegalovirus (CMV) in 32 (13.9%), Epstein–Barr virus (EBV) in 9 (3.9%), Hepatitis B virus (HBV) in 10 (4.3%), C. albicans in 7 (3%), M. tuberculosis in 3 (1.3%), Hepatitis C virus (HCV) in 2 (0.8%), and C. glabrata in 1 (0.4%) patient. Although mono-agent co-infections were determined in 69 of 87 people living with HIV, two-agent co-infections were detected in 16 HIV patients, and three-agent co-infections were identified in two HIV patients. Considering the correlation between the CD4/CD8 ratio and infection positivity, a moderate negative correlation was determined with HIV RNA viral load and CMV infection. The CD4/CD8 ratio had a low negative correlation with EBV and C. albicans infections. It was also found that the follow-up of HIV RNA load in the diagnosis of T. pallidum, CMV, EBV, and C. albicans may be meaningful. Opportunistic infections mainly affect immunosuppressed patients and can be prevented with effective treatment. Although it is already known that HIV patients may face different infections during their treatment, it was concluded that more attention should be paid to T. pallidum, CMV, EBV, and C. albicans agents. These infections should be routinely monitored with HIV viral load and the CD4/CD8 ratio.

For COVID-19 (Coronavirus Disease-2019) cases, detecting host-based factors that predispose to infection is a very important research area. In this study, the aim is to investigate the MBL2 and NOS3 gene polymorphisms in COVID-19 patients with lung involvement, whose first nasopharyngeal PCR results were negative. Seventy-nine patients diagnosed with COVID-19 between April-June 2020 who were admitted to a university hospital, and 100 healthy controls were included. In the first statistical analysis performed between PCR-positive, CT-negative and PCR-negative, CT-positive patients; the AB of MBL2 genotype was significantly higher in the first group (p = 0.049). The B allele was also significantly higher in the same subgroup (p = 0.001). The absence of the AB genotype was found to increase the risk of CT positivity by 6.9 times. The AB genotype of MBL2 was higher in healthy controls (p = 0.006). The absence of the AB genotype was found to increase the risk of CT positivity; also, it can be used for early detection and isolation of patients with typical lung involvement who had enough viral loads, but whose initial PCR results were negative.