Comparison of clinical outcomes associated with RSV and influenza infections in adults: a multicenter study from Türkiye (for AP-TR)
Year: 2026
Type: article
Study design: Observational Study
Abstract: 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.
Authors: İrem Akdemir, Hasan Selçuk Özger, Tuğba Akkaya Hocagil, Bircan Kayaaslan, Handan Alay, Özge Özgen Top, Esra Kazak, Gamze Kalın Ünüvar, Ayşe Erbay, Güle Çınar, Sesin Kocagöz, Birsen Mutlu, Yasemin Çakır, Çiğdem Mermutluoğlu, Funda Memişoğlu, Seçil Deniz, Serap Şimşek Yavuz, Sema Alp, Derya Korkmaz, Heval Can Bilek, Ayşegül İnci Sezen, Faruk Karakeçili, Neşe Saltoğlu, Elif Hakko, Bedia Dinç, Hamidullah Uyanık, Gülendam Bozdayı, Harun Ağca, Ömür Mustafa Parkan, Zeynep Ceren Karahan, Neval Yurttutan, Aynur Karadenizli, Murşit Hasbek, Nida Özcan, Barış Otlu, İlknur Kaleli, Sevim Meşe, Arzu Sayıner, Yeliz Çetinkol, Yeliz Tanrıverdi Çaycı, Fatma Bayrak Erdem, Barış Gülhan, Ömer Küçükbasmacı, Melda Özdamar, Elif Naz Elmacı, Kerem Sancar, Berivan Şahin, Gülay Korukluoğlu, Sibel Aydoğan, Ali Ağaçfidan, Şebnem Eren Gök, Alpay Azap, Esin Şenol
Institutions: Ankara University, Koç University, Ankara Bilkent City Hospital, Atatürk University, Gazi University, Bursa Uludağ Üni̇versi̇tesi̇, Erciyes University, Yozgat Bozok Üniversitesi, Kocaeli Üniversitesi, Sivas Cumhuriyet Üniversitesi, Dicle University, Inonu University, Pamukkale University, Istanbul University-Cerrahpaşa, Istanbul University, Dokuz Eylül University, Afyonkarahisar Sağlık Bilimleri Üniversitesi, Ondokuz Mayıs University, Bakırköy Dr.Sadi Konuk Eğitim ve Araştırma Hastanesi, Erzincan Binali Yıldırım University
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,900
OpenAlex ID: W7204225730