Detection of RSV in Children ≤2 years from SARS CoV-2 negative samples at National Public Health Laboratory, Nepal

Introduction: Respiratory syncytial viruses also known as human respiratory syncytial viruses (HRSV) are highly transmissible respiratory pathogens & the leading cause of hospitalization due to lower respiratory infection, especially in the pediatric population. This study is intended to determine the RSV positivity in SARS-CoV-2 negative samples obtained from patients ≤ 2 years, collected from September to December 2021, when RSV infection is more common. Method: SARS-CoV-2 negative archived nasopharyngeal samples of children ≤2 years from September to December 2021 at National Public Health Laboratory (NPHL) were tested for RSV by real-time reverse transcriptase Polymerase Chain Reaction (RT-PCR) using CDC RSV Kit. The Pan-RSV primer/probe set used for the universal detection of RSV and duplex RSV subgroup primer/probe set used for the detection and subgroup-specific identification of RSV A and B. Result: A total of 294 SARS-CoV-2 negative samples from children less than 2 y were tested. RSV A was identified in 100(34%) and RSV B was detected in 6(2%) samples. In all, 106(36%) samples were positive for RSV. Here we report RSV positivity rate of 36% in SARS-CoV-2 negative samples which were left undiagnosed during the surge of COVID-19 cases. Conclusion: Our study thereby highlights the need for an accurate and rapid differential or multiplex kits for screening respiratory disease for effective disease management in the pediatric population