Abstract
Background The evaluation of coronavirus disease 2019 (COVID-19) patients with respiratory secondary bacterial infection, and the causative pathogens, is crucial for the treatment plan of those patients and to ensure the effective needed treatment with antibiotics and to decrease its abuse. Aim To clarify the incidence of bacterial infection in patients with COVID-19 and sensitivity to antibiotics. Patients and methods Samples of sputum were collected from 120 patients with confirmed COVID-19 by clinical, laboratory, radiological signs of pneumonia, or PCR, the severity of COVID-19 was classified as moderate and severe. The moderate type included patients with pneumonia without hypoxemia. The severe type was characterized by (a) dyspnea (respiratory rate >= 30/min), (b) blood oxygen saturation less than or equal to 93%, and (c) PaO2/FiO(2 )ratio less than 300 or lung infiltrates more than 50%. If one of the above items was met, it was classified as severe. Then, all cases were sent for screening of the presence of secondary bacterial infections by quantitative sputum bacterial culture and sensitivity. Positive cases of bacterial infection were classified into patients with early bacterial infection less than 15 days from COVID-19 infection and patients with late bacterial infections after more than 15 days of COVID-19 infection. Results In total, 40 (33.3%) cases out of 120 cases of COVID-19 showed bacterial growth, while 80 (66.7%) cases were negative for bacterial secondary infection. The most common organisms isolated were Klebsiella pneumoniae 12 cases, streptococci 10 cases, MERSA eight cases, Escherichia coli five cases and mixed infection by E. coli, Klebsiella, and Candida in five cases, Staphylococcus aureus was the same rate in early and late infections, all streptococci were early infection, and more cases of K. pneumoniae were late infection nine cases out of 13, where E. coli was early infection four cases out of five. All mixed infections were late. Conclusion Hidden secondary bacterial infection should be screened in COVID-19 patients. Early bacterial infections and moderate COVID-19 pneumonia are mainly caused by Gram-positive bacteria, but late bacterial infections and severe COVID-19 pneumonia are mainly caused by Gram-negative bacteria.