Clinical Presentation of Seasonal Respiratory Viruses in California, May 2020–July 2022

The coronavirus disease 2019 (COVID-19) pandemic caused disruptions in the transmission of seasonal respiratory viruses. COVID-19 is characterized by a range of non-specific symptoms, making it difficult to differentiate from other seasonal respiratory viruses. The goal of this analysis was to further understand trends in the circulation and differences in reported symptoms between respiratory pathogens during the COVID-19 pandemic. From May 2020 to July 2022 a sentinel surveillance project collected data and respiratory specimens in outpatient settings across California and tested them for 19 respiratory viruses. Data were analyzed by identified respiratory pathogen to describe trends and clinical presentations. Multiple logistic regression was used to estimate odds of each respiratory pathogen by reported symptoms. We included results from 19,183 specimens, of which 8,599 (44.8%) tested positive for a pathogen, including 3,742 (20.0%) for SARS-CoV-2 and 3,057 (15.9%) for rhinovirus/enterovirus. Those reporting systemic symptoms had significantly higher adjusted odds of testing positive for influenza (aOR=9.2; 95%CI, 6.7-13.1) or SARS-CoV-2 (aOR=2.4; 95%CI, 2.2-2.6). The variability in testing positive for a pathogen among people reporting different symptom profiles underscores a potential benefit of complete testing algorithms to complement syndromic diagnostics, improving public health awareness and clinical guidance.