Evaluation of common respiratory viruses other than SARS-CoV-2 in hospitalized children during the COVID-19 pandemic.

backgroundThe COVID-19 pandemic has profoundly altered the epidemiology of viral respiratory infections; however, other respiratory viruses besides SARS-CoV-2 continue to cause illness in hospitalized children. This study aimed to assess the frequency of common respiratory viruses, other than SARS-CoV-2, in children hospitalized with respiratory symptoms during the COVID-19 pandemic, and to examine rates of co-infection with multiple viruses. MATERIALS AND

methodsThis study included 92 pediatric patients admitted to the Children's Medical Center in Tehran, Iran, between December 2021 and March 2022, all of whom tested negative for SARS-CoV-2 by Real-time PCR. Nasal swabs were collected and PCR/RT-PCR tests were used to identify other respiratory viruses, including Influenza A (FluA), Influenza B (FluB), Respiratory Syncytial Virus (RSV), Parainfluenza Virus (PIV), Human Cytomegalovirus (CMV), Adenovirus (ADV), Human Coronavirus OC43 (HCOV-OC43), and Metapneumovirus (MPV). Clinical information, including symptoms, laboratory results, and patient outcomes, was also gathered and analyzed.

resultsAmong the 92 patients, 67.3% (n = 62) tested positive for at least one of the targeted respiratory viruses. FluB was the most prevalent, detected in 60.9% (n = 56) of cases, followed by CMV in 12% (n = 11), and HCOV-OC43 in 5.4% (n = 5). RSV and ADV were each identified in 2 patients (2.2%), while PIV was found in 3 patients (3.2%), including two cases of PIV-1 and one case of PIV-3. No cases of FluA or MPV were detected. Co-infections occurred in 13 patients (14.1%), with FluB exhibiting the highest rate of co-infection, particularly alongside CMV in 7 cases, followed by PIV (3 cases), ADV (2 cases), and HCOV-OC43 (2 cases). Laboratory comparisons among patients with single-virus infections (FluB, CMV, and HCOV-OC43), those with no detected virus, and those with co-infections revealed a statistically significant difference in lymphocyte counts (p-value = 0.027).

conclusionWhile the focus during the pandemic has largely been on SARS-CoV-2, other respiratory viruses, particularly Influenza B, continue to affect hospitalized children. The frequent occurrence of co-infections with multiple viruses underscores the need for comprehensive diagnostic testing to accurately identify respiratory pathogens in pediatric patients. These results highlight the importance of sustained monitoring and management of diverse respiratory viruses beyond SARS-CoV-2, given their continued clinical relevance.