Influenza and RSV incidence during COVID-19 pandemic—an observational study from in-hospital point-of-care testing

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has forced the implementation of unprecedented public health measures strategies which might also have a significant impact on the spreading of other viral pathogens such as influenza and Respiratory Syncytial Virus (RSV) . The present study compares the incidences of the most relevant respiratory viruses before and during the SARS-CoV-2 pandemic in emergency room patients. We analyzed the results of in total 14,946 polymerase chain reaction point-of-care tests (POCT-PCR) for Influenza A, Influenza B, RSV and SARS-CoV-2 in an adult and a pediatric emergency room between December 1, 2018 and March 31, 2021. Despite a fivefold increase in the number of tests performed, the positivity rate for Influenza A dropped from 19.32% (165 positives of 854 tests in 2018/19), 14.57% (149 positives of 1023 in 2019-20) to 0% (0 positives of 4915 tests) in 2020/21. In analogy, the positivity rate for Influenza B and RSV dropped from 0.35 to 1.47%, respectively, 10.65-21.08% to 0% for both in 2020/21. The positivity rate for SARS-CoV2 reached 9.74% (110 of 1129 tests performed) during the so-called second wave in December 2020. Compared to the two previous years, seasonal influenza and RSV incidence was eliminated during the COVID-19 pandemic. Corona-related measures and human behavior patterns could lead to a significant decline or even complete suppression of other respiratory viruses such as influenza and RSV.