Background: Coronavirus disease 2019 (COVID-19) is spreading. Here, we summarized the composition of pathogens in fever clinic patients and analyzed the characteristics of different respiratory viral infections. Methods: Retrospectively collected patients with definite etiological results using nasal and pharyngeal swabs in a fever clinic. Results: Overall, 1860 patients were screened, and 136 patients were enrolled. 72 (52.94%) of them were diagnosed as influenza (Flu) A virus infection. 32 (23.53%) of them were diagnosed as Flu B virus infection. 18 (13.24%) and 14 (10.29%) of them were diagnosed as COVID-19 and respiratory syncytial virus (RSV) infections, respectively. The COVID-19 group had a higher rate of contact with the epidemic area within 14 days and of clustering onset than other groups. Fever was the most common symptom in these patients. The ratio of fever to the highest temperature was higher in Flu A virus infection patients than in COVID-19 patients. COVID-19 patients had a lower white blood cell count and neutrophil count than Flu A virus and RSV infection groups, but higher lymphocyte count than Flu A and B virus infection groups. The COVID-19 group (83.33%) had a higher rate of pneumonia in chest CT scans than Flu A and B virus infection groups. Conclusions: Influenza viruses accounted for a large proportion of respiratory virus infection even during the epidemic of COVID-19 in Beijing. No single symptom or laboratory finding was suggestive of a specific respiratory virus; however, epidemic history was significant for the screening of COVID-19. (C) 2020 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.

Clinical data suggest that during the current COVID-19 pandemic, children are less prone than adults to SARS-CoV-2 infection. Our purpose was to determine the frequency of SARS-CoV-2 in children vs. adults during the 2020 pandemic in Warsaw, Poland, and to investigate whether RSV and/or influenza A/B infections were associated with SARS-CoV-2 infections. We present results of RT-PCR tests for SARS-CoV-2 performed in Warsaw, Poland. Some of the pediatric subjects were also PCR-tested for RSV, and A and B influenza. We compared the test results from the four groups of symptomatic and asymptomatic subjects: 459 symptomatic pediatric patients (children 0-18 years old), 1774 symptomatic adults, 445 asymptomatic children, and 239 asymptomatic adults. 3.26% (15/459) of symptomatic pediatric patients were positive for SARS-CoV-2 in contrast to 5.58% (99/1774) of symptomatic adults (p= 0.0448). There were no SARS-CoV-2 positive cases in the group of asymptomatic children (0/445) and two positive cases in the group of asymptomatic adults (2/239), i.e., 0.83%. In the group of symptomatic pediatric patients, 17.14% (6/35) (p= 0.0002) were positive for RSV, 8.16% (4/49) were positive for influenza A, and 2.04% (1/49), thus 10.20% (5/49) (p= 0.0176) for influenza A/B. Children were less prone to SARS-CoV-2 infection than the adults during the COVID-19 pandemic in Warsaw. Higher percentage of symptomatic children was infected with RSV or influenza A/B than with SARS-CoV-2. This suggests a necessity for the testing for all these viruses for an early identification and isolation of SARS-CoV-2-positive patients for an ensuing 2020 autumn return of COVID-19.