Precautions are Needed for COVID-19 Patients with Coinfection of Common Respiratory Pathogens

BackgroundWith the ongoing outbreak of Coronavirus Disease 2019 (COVID-19), infected patients within and beyond the epidemic area, Wuhan, China, showed different epidemiological and clinical characteristics. There is a paucity of data concerning coinfection with other common respiratory pathogens in COVID-19 patients outside of Wuhan. MethodsWe conducted a double-centre study recruiting 68 patients with severe acute respiratory coronavirus 2 (SARS-CoV-2) infection confirmed by nucleic acid testing in Qingdao and Wuhan from January 17 to February 16, 2020. Indirect immunofluorescence was performed to detect the specific IgM antibody against common respiratory pathogens in collected acute phase serum. ResultsOf the 68 patients with SARS-CoV-2 infection, 30 (44.12%) were from Qingdao. The median age of Qingdao and Wuhan patients were 50 (IQR: 37-59) and 31 (IQR: 28-38) years, respectively, and the majority of patients were female in Qingdao (60.00%) and Wuhan (55.26%). Among COVID-19 patients in Qingdao, 24 (80.00%) of them had IgM antibodies against at least one respiratory pathogen, whereas only one (2.63%) of the patients in Wuhan had positive results for serum IgM antibody detection (P<0.0001). The most common respiratory pathogens detected in Qingdao COVID-19 patients were influenza virus A (60.00%) and influenza virus B (53.33%), followed by mycoplasma pneumoniae (23.33%) and legionella pneumophila (20.00%). While the pattern for coinfection in patients with community-acquired pneumonia in Qingdao was quite different, with a positive rate of only 20.90%. InterpretationWe reported a large proportion of COVID-19 patients with coinfection of seasonal respiratory pathogens in Qingdao, northeast China, which differed greatly from the patients in Wuhan, central China. Precautions are needed when dealing with COVID-19 patients beyond the epidemic centre who have coinfection with other respiratory pathogens. We highly recommend adding SARS-CoV-2 to routine diagnostic testing in capable hospitals to prevent misdetection of the virus.