Coinfections with Respiratory Pathogens among COVID-19 Patients in Korea

The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in upper and lower respiratory specimens and coinfection with other respiratory pathogens in patients with coronavirus disease 2019 (COVID-19) was investigated. Study subjects ( N  = 342) were retrospectively enrolled after being confirmed as SARS-CoV-2 positive, and their nasopharyngeal swab (NPS), oropharyngeal swab (OPS), and sputum specimens were restored for SARS-CoV-2 retesting and respiratory pathogen detection. The majority of the subjects (96.5%, N  = 330) were confirmed as SARS-CoV-2 positive using NPS/OPS specimens. Among the COVID-19 patients ( N  = 342), 7.9% ( N  = 27) and 0.9% ( N  = 3) were coinfected with respiratory viruses and Mycoplasma pneumoniae , respectively, yielding an 8.8% ( N  = 30) overall respiratory pathogen coinfection rate. Of the respiratory virus coinfection cases ( N  = 27), 92.6% ( N  = 25) were coinfected with a single respiratory virus and 7.4% ( N  = 2) with two viruses (metapneumovirus/adenovirus and rhinovirus/bocavirus). No triple coinfections of other respiratory viruses or bacteria with SARS-CoV-2 were detected. Respiratory viruses coinfected in the patients with COVID-19 were as follows: rhinovirus ( N  = 7, 2.1%), respiratory syncytial virus A and B ( N  = 6, 1.8%), non-SARS-CoV-2 coronaviruses (229E, NL63, and OC43, N  = 5, 1.5%), metapneumovirus ( N  = 4, 1.2%), influenza A ( N  = 3, 0.9%), adenovirus ( N  = 3, 0.9%), and bocavirus ( N  = 1, 0.3%). In conclusion, the diagnostic value of utilizing NPS/OPS specimens is excellent, and, as the first report in Korea, coinfection with respiratory pathogens was detected at a rate of 8.8% in patients with COVID-19.