Coinfections may be more common in COVID-19 than previously reported
The rate of coinfection with other respiratory pathogens in patients with COVID-19 may be higher than previously thought, according to a research letter published in JAMA.
“Early reports from China suggested that coinfection with other respiratory pathogens was rare. If this were the case, patients positive for other pathogens might be assumed unlikely to have SARS-CoV-2,” David Kim, MD, PhD, from the department of emergency medicine at Stanford University School of Medicine, and colleagues wrote. “The 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.”
From March 3 to 25, the researchers tested nasopharyngeal swabs from patients with symptoms, such as cough, fever and dyspnea, from multiple sites in northern California for SARS-CoV-2 and other respiratory pathogens, including influenza A or B, respiratory syncytial virus, non-SARS-CoV-2 Coronaviridae, adenovirus, parainfluenza 1 to 4, human metapneumovirus, rhinovirus/enterovirus, Chlamydia pneumoniae and Mycoplasma pneumoniae.
Of 1,217 specimens collected from 1,206 patients, 116 (9.5%) were positive for SARS-CoV-2 and 318 (26.1%) were positive for one or more non-SARS-CoV-2 pathogen. At least one additional respiratory pathogen was identified in 24 of the 116 specimens positive for SARS-CoV-2 (20.7%) vs. 294 of the 1,011 specimens negative for SARS-CoV-2 (26.7%; 6-percentage-point difference; 95% CI, –2.3 to 14.3). The most common coinfections included rhinovirus/enterovirus (6.9%), respiratory syncytial virus (5.2%) and non-SARS-CoV-2 Coronaviridae (4.3%). The researchers noted that differences in rates of non-SARS-CoV-2 pathogens between specimens positive vs. negative for SARS-CoV-2 did not reach statistical significance.
Results also showed that of the 318 specimens positive for at least one non-SARS-CoV-2 pathogens, 24 were also positive for SARS-CoV-2 (7.5%), and 92 of 899 specimens negative for other pathogens were positive for SARS-CoV-2 (10.2%; 2.7-percentage-point difference; 95% CI, –1 to 6.4).
When analyses were restricted to one specimen per patient, results were similar, with 23 of 115 patients positive for SARS-CoV-2 (20%) testing positive for other pathogens and 292 of 1,091 patients negative for SARS-CoV-2 testing positive for other pathogens (26.8% 6.8-percentage-point difference; 95% CI, –1.5 to 15). Additionally, 23 of 315 patients positive for other pathogens (7.3%) were also positive for SARS-CoV-2 compared with 92 of 891 patients negative for other pathogens (10.3%; 3-percentage-point difference; 95% CI, –0.7 to 6.7).
When comparing patients with coinfection vs. those with SARS-CoV-2 only, the mean age was similar between both groups (46.9 vs. 51.1 years; difference, 4.2 years; 95% CI, –4.8 to 13.2).
In light of these findings, the researchers noted that testing positive for a non-SARS-CoV-2 pathogen “may not provide reassurance that a patient does not also have SARS-CoV-2.”
They acknowledged that the study was not without limitations, including that they focused on samples from a single region and had limited sample size, among other issues.
“Nonetheless, these results suggest that routine testing for non–SARS-CoV-2 respiratory pathogens during the COVID-19 pandemic is unlikely to provide clinical benefit unless a positive result would change disease management (eg, neuraminidase inhibitors for influenza in appropriate patients),” the researchers wrote. – by Melissa Foster
Disclosures: The authors report no relevant financial disclosures.