Analysing the spectrum of virological profile and its clinical significance in patients with severe acute respiratory infection in a tertiary care hospital

Background: Severe Acute Respiratory Infection (SARI) is a major cause of morbidity and mortality in developing countries and remains a syndromic hallmark for multiple respiratory viruses. In the aftermath of the COVID-19 pandemic, characterizing the circulating viral pathogens and understanding their association with clinical severity has become increasingly important for patient triage and public health preparedness.Materials and Methods: This prospective observational study was conducted at a tertiary care hospital in Tamil Nadu, India, enrolling 49 adult patients hospitalized with WHO-defined SARI between January 2024 and January 2025. Respiratory samples were tested using multiplex real-time RT-PCR for common respiratory viruses including SARS-CoV-2, Influenza A/B, RSV, and others. Demographic, clinical, and laboratory data were recorded, and outcomes such as ICU admission, oxygen support, and mortality were analyzed. Multivariate logistic regression was used to identify independent predictors of severe outcomes.Results: The most frequently detected pathogens were SARS-CoV-2 (30.6%) and Influenza A (20.4%), followed by RSV and Rhinovirus. Virus-positive patients had significantly higher white blood cell counts (p = 0.0259), but no significant differences in CRP, D-dimer, or oxygen saturation. Mortality increased with escalating respiratory support, reaching 33.3% among mechanically ventilated patients. Multivariate analysis identified age > 60 years as a strong predictor of ICU admission or mortality (adjusted OR 11.01; 95% CI: 1.36–89.19; p = 0.0246), while comorbidities were unexpectedly associated with lower odds of severe outcomes (aOR 0.14; p = 0.0109).Conclusions: SARS-CoV-2 and Influenza A remain dominant viral pathogens among hospitalized SARI patients in India. Older age is independently associated with worse outcomes, reinforcing the need for age-based risk stratification. Virological profiling and early oxygen support assessments offer valuable insights into clinical severity and can inform future SARI management strategies in resource-limited settings.