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

Abstract

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.

Keywords: COVID-19 influenza; In-hospital; Point-of-care testing; Polymerase chain reaction; Prevalence; RSV; SARS-CoV-2.

Fig. 1

Instrument, cartridge and scheme of the POCT-PCR testing. A POCT-PCR workstation with GeneXpert XVI-16 module instrument (left) and GeneXpert Xpress Software on a desktop computer (right). B Xpert Xpress Cartridge for Quadruple-POCT-PCR test. C Schematic representation of the respective test strategy from December 2018 to March 2021

Fig. 2

POCT-PCR tests for SARS-COV-2 from May 2020 to February 2021. A The number of POCT-PCR tests for SARS-COV-2 performed monthly increased until November 2020 and then stayed stable around 1200 total tests per month. B During the so-called second SARS-CoV-2 wave, the positive test rate increased from September 2020 and reached its maximum in December 2020 with a subsequent decrease

Fig. 3

POCT-PCR tests for Influenza A, Influenza B and RSV from 2018 to 2021. A The total number of seasonal POCT-PCR tests for Influenza A, Influenza B and RSV was roughly the same in the 2018/19 and 2019/20 seasons and increased by fivefold in 2020/21. B–D The number of positive tests for Influenza and RSV in the 2018/19 and 2019/20 seasons completely disappeared in 2020/21

Fig. 4

Overall positive POCT-PCR tests 2018–2021. During the COVID-19 pandemic, Influenza and RSV infections disappeared when compared to previous seasons