SARS‐CoV‐2, Influenza Virus, and Respiratory Syncytial Virus Coinfections Among Symptomatic Outpatients in Lorestan Province, Iran: A Retrospective Cross‐Sectional Study

ABSTRACT Background and Aims Pathogenic viruses represent a principal etiology of acute respiratory tract disease. Concurrent detection of multiple respiratory pathogens has been associated with diagnostic challenges, therapeutic complications, and unfavorable outcomes in patients with COVID‐19. This investigation aimed to characterize the frequency of concurrent SARS‐CoV‐2, influenza virus, and human respiratory syncytial virus (RSV) infections among individuals presenting with suspected COVID‐19 symptoms during the pandemic period in Lorestan Province, Iran. Methods A retrospective observational study was conducted among 196 participants who presented with suspected COVID‐19 and clinically compatible respiratory symptoms at regional healthcare facilities in Lorestan Province from July through December 2022. Nasopharyngeal specimens were obtained from all participants, maintained at 2°C–8°C during transit on ice, and subsequently subjected to nucleic acid extraction and multiplex quantitative reverse‐transcription polymerase chain reaction (qRT‐PCR) analysis at the Molecular Virology Laboratory. Results Of 196 participants evaluated, positivity rates were as follows: SARS‐CoV‐2, 40.81%; influenza virus, 30.10%; and RSV, 5.10%. Dual infections were identified in the following proportions: SARS‐CoV‐2 with RSV 3.57%, SARS‐CoV‐2 with influenza virus 11.22%, and RSV with influenza 3.06%. Simultaneous detection of all three pathogens was documented in 2.04% of the study population. Conclusion This study documents the circulation of SARS‐CoV‐2, influenza virus, and RSV among symptomatic outpatients in Lorestan Province during the study period, including a limited number of dual and triple coinfections. These findings highlight the importance of continued respiratory virus surveillance and multiplex molecular testing in outpatient settings. Nevertheless, the small numbers of RSV‐positive patients, triple‐infection cases, and children younger than 6 years limit the strength of subgroup‐based inferences; therefore, age‐specific, pediatric, and symptom‐related findings should be interpreted cautiously. Further studies with larger and more diverse populations are warranted.