Spectrum of Non-SARS-CoV-2 Respiratory Viruses Among Symptomatic Post-COVID Adults in a North Indian Tertiary Care Center: A 2022 Surveillance Study

Post-COVID, patients often suffer from long-term respiratory complications, contributing to increased susceptibility to secondary respiratory infections. Emerging surveillance studies have reported resurgence and altered seasonality of respiratory viruses following relaxation of non-pharmaceutical interventions, underscoring the need for surveillance of respiratory viruses in this cohort. The study included 108 post-COVID-19 patients (>18 years) presenting with respiratory symptoms from January to December 2022 in the Department of Medicine in Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, a tertiary care facility in North India. Nasopharyngeal swabs, nasopharyngeal aspirates, and endotracheal aspirates were collected, and SARS-COV-2 RNA testing was performed on all, and samples negative for the same were screened for influenza A (H1N1, H3N2), influenza B, human bocavirus (hBoV), human adenovirus (hAdV), respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and human rhinovirus (hRV). The statistical analysis was predominantly descriptive and was conducted using MS Excel 2024 (Microsoft Corp., Redmond, WA). The frequencies and percentages of categorical variables were summarized, and associations were evaluated using Fisher's exact test. Multivariable modeling was not conducted as a result of the descriptive study design and the small sample size. Among total patients, 20.37% were positive for respiratory viruses. Maximum positivity was observed with influenza A (37.5%), followed by hMPV (17%). A higher viral positivity rate was seen in females (p = 0.0361, Fisher's exact test) and the geriatric age group (60 years, n = 40). Sequencing was done, and the circulating types were influenza A H1N1, influenza B Victoria type, RSV type A, and rhinovirus type A and C. This study describes the spectrum of respiratory viruses detected among symptomatic post-COVID patients with influenza, hMPV, and RSV as the predominant pathogens.