Co-Infections Uncovered in One-Fifth of COVID-19 Samples
— Testing for other respiratory illnesses may not rule out COVID-19 — and vice versa
Just because a patient tests positive for the COVID-19 coronavirus doesn’t mean that other pathogens aren’t at work too, researchers found.
In a small sample in Northern California, 20.7% of respiratory specimens positive for SARS-CoV-2, the virus that causes COVID-19, were also positive for one or more additional pathogens, reported James Quinn, MD, of Stanford University School of Medicine in Stanford, California, and colleagues, writing in a research letter in JAMA.
They noted early reports from China that suggested potential co-infection with other respiratory pathogens was “rare,” though CDC suggested testing for other respiratory pathogens in patients with suspected COVID-19, adding “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.”
Quinn and colleagues examined 1,217 nasopharyngeal specimens from symptomatic patients reporting, for example, cough, fever, and shortness of breath, and found 9.5% were positive for SARS-CoV-2, with 24 of those testing positive for additional pathogens, such as influenza, respiratory syncytial virus, and non-SARS-CoV-2 Coronaviridae.
In addition, patients with co-infections did not differ significantly in age (mean age 47) versus those infected with SARS-CoV-2 only (mean age 51).
The most common co-infections were
- rhinovirus/enterovirus (7%)
- respiratory syncytial virus (5%)
- non-SARS-CoV-2 Coronaviridae (4%)
“These results suggest higher rates of co-infection between SARS-CoV-2 and other respiratory pathogens than previously reported,” Quinn and colleagues wrote.
“The presence of a non-SARS-CoV-2 pathogen may not provide reassurance that a patient does not also have SARS-CoV-2.”
While they noted their results were limited to a single region in California, as well as their limited sample size, they concluded routine testing for non-SARS-CoV-2 respiratory pathogens “is unlikely to provide clinical benefit unless a positive result would change disease management” (for example, neuraminidase inhibitors for influenza patients) during this COVID-19 pandemic.
The authors disclosed no conflicts of interest.