Early reports from China suggested that co-infection with other respiratory pathogens was rare.
However, a new study performed in Northern California shows that co-infection rates between SARS-CoV-2 and other respiratory pathogens is higher than expected, with no significant difference in rates of SARS-CoV-2 infection in patients with and without other pathogens.
In this way, from March 3 through 25, 2020, authors performed Reverse Transcription Polymerase Chain Reaction (RT-PCR) tests for SARS-CoV-2 and other respiratory pathogens on nasopharyngeal swabs of symptomatic patients (eg, cough, fever, dyspnea). At some sites, specimens were simultaneously tested for a panel of non–SARS-CoV-2 respiratory pathogens (influenza A/B, respiratory syncytial virus, non–SARS-CoV-2 Coronaviridae, adenovirus, parainfluenza 1-4, human metapneumovirus, rhinovirus/enterovirus, Chlamydia pneumoniae, Mycoplasma pneumoniae).
Researchers studied 1,217 specimens tested for SARS-CoV-2 and other respiratory pathogens, from 1,206 unique patients; 116 of the 1,217 specimens (9.5%) were positive for SARS-CoV-2 and 318 (26.1%) were positive for 1 or more non–SARS-CoV-2 pathogens.
Of the 116 specimens positive for SARS-CoV-2, 24 (20.7%) were positive for 1 or more additional pathogens, compared with 294 of the 1,101 specimens (26.7%) negative for SARS-CoV-2 (difference, 6.0%). The most common co-infections were rhinovirus/enterovirus (6.9%), respiratory syncytial virus (5.2%), and non–SARS-CoV-2 Coronaviridae (4.3%).
Of 318 specimens positive for 1 or more non–SARS-CoV-2 pathogens, 24 (7.5%) were also positive for SARS-CoV-2. Among 899 specimens negative for other pathogens, 92 (10.2%) were positive for SARS-CoV-2 (difference, 2.7%).
The findings, while small and isolated to one area of the country, are concerning, because earlier research from China had suggested that co-infections were very rare. One reason that’s important is because the Centers for Disease Control and Prevention (CDC) endorsed testing for other respiratory pathogens, suggesting that evidence of another infection could aid the evaluation of patients with potential COVID-19 in the absence of widely available rapid testing for SARS-CoV-2, given the lack of accessible testing for the coronavirus. But the presence of another virus may not provide reassurance that a patient does not also have SARS-CoV-2, the authors wrote.
Link to the paper: https://doi.org/10.1001/jama.2020.6266
Editorial Disclaimer: information published during the 2020 COVID-19 pandemic may be updated frequently to reflect the dynamic nature of current understanding.