Akdemir, İrem; Selçuk Özger, Hasan; Hocagil, Tuğba Akkaya; Kayaaslan, Bircan; Alay, Handan; Top, Özge Özgen; Kazak, Esra; Kalın Ünüvar, Gamze; Erbay, Ayşe; Çınar, Güle

Objectives Respiratory syncytial virus (RSV) is an increasingly recognized cause of serious respiratory illness in adults, yet data from middle-income countries remain scarce. This study aimed to compare clinical outcomes of RSV and influenza virus infections in hospitalized and outpatient adults in Türkiye. Methods This retrospective multicenter study included 3299 adult patients (≥18 years) with polymerase chain reaction-confirmed RSV (n = 628) or influenza (n = 2671) from 21 centers across Türkiye between January 2022 and March 2024. The primary outcome was viral infection–related hospitalization. The secondary composite outcome was intensive care unit (ICU) admission and/or 30-day mortality among hospitalized patients. Propensity score–based overlap weighting was used to adjust for baseline differences including age, risk group, clinical severity, co-infection status, and study center. Results After overlap weighting, RSV infection was not significantly associated with increased hospitalization risk compared to influenza (odds ratio [OR]: 0.96, 95% confidence interval [CI]: 0.77-1.20, P = 0.705). Similarly, no significant difference was observed in the composite outcome of ICU admission or 30-day mortality (OR: 1.40, 95% CI: 0.95-2.05, P = 0.088). Age ≥60 years, high-risk comorbidities, and severe acute respiratory infection presentation were the primary independent predictors of both hospitalization and worse outcomes. Bacterial or fungal co-infections and secondary infections were observed in 12.9% and 7.3% of hospitalized patients, respectively, with no significant difference between RSV and influenza groups. Conclusion After adjustment for baseline characteristics, RSV and influenza were associated with comparable risks of hospitalization and severe clinical outcomes in adults. Host-related factors, particularly older age and underlying comorbidities, were the dominant determinants of adverse outcomes. These findings from a largely unvaccinated, middle-income country cohort highlight the need to expand RSV and influenza vaccination programs targeting high-risk adult populations.

Dogan, N.; Al Dogruman, F.; Kocman, N. U.; Dinleyici, E. C.; Oguz, I.; Aydin, M.

Sargin Altunok, Elif; Sayan, Murat; Akhan, Sila; Aygen, Bilgehan; Yildiz, Orhan; Tekin Koruk, Suda; Mistik, Resit; Demirturk, Nese; Ural, Onur; Kose, Şükran

Background Drug resistance development is an expected problem during treatment with protease inhibitors (PIs), this is largely due to the fact that Pls are low-genetic barrier drugs. Resistance-associated variants (RAVs) however may also occur naturally, and prior to treatment with Pls, the clinical impact of this basal resistance remains unknown. In Turkey, there is yet to be an investigation into the hepatitis C (HCV) drug associated resistance to oral antivirals. Materials and methods 178 antiviral-naïve patients infected with HCV genotype 1 were selected from 27 clinical centers of various geographical regions in Turkey and included in the current study. The basal NS3 Pls resistance mutations of these patients were analyzed. Results In 33 (18.5%) of the patients included in the study, at least one mutation pattern that can cause drug resistance was identified. The most frequently detected mutation pattern was T54S while R109K was the second most frequently detected. Following a more general examination of the patients studied, telaprevir (TVR) resistance in 27 patients (15.2%), boceprevir (BOC) resistance in 26 (14.6%) patients, simeprevir (SMV) resistance in 11 (6.2%) patients and faldaprevir resistance in 13 (7.3%) patients were detected. Our investigation also revealed that rebound developed in the presence of a Q80K mutation and amongst two V55A mutations following treatment with TVR, while no response to treatment was detected in a patient with a R55K mutation. Conclusion We are of the opinion that drug resistance analyses can be beneficial and necessary in revealing which variants are responsible for pre-treatment natural resistance and which mutations are responsible for the viral breakthrough that may develop during the treatment.