Bacterial Co-infection and Secondary Infection in SARS-CoV-2 (COVID- 19) Adult Patients in a National Tertiary Infectious Disease Hospital

<bold>Introduction:</bold> Concerning the exponential growth of COVID-19 confirmed cases in the Philippines, there is a need to fill the gap in knowledge regarding the use of antibiotics to treat COVID-19. Understanding bacterial co-infections and secondary infections, the causative pathogen, and antimicrobial use is vital for treating patients with COVID-19. <bold>Methodology:</bold> A retrospective research design was used in the study. Any positive cultures from blood, sputum, or deep respiratory samples were considered COVID-19-related infections. <bold>Result:</bold> The most common clinical symptoms of COVID-19 patients with bacterial co-infection and secondary infection were cough (79.7%), fever (77%), and dyspnea (68.9%). Of 74 patients, 31.1% were given high-flow nasal cannula oxygen support. Most of these patients had severe and critical COVID-19 infection in 32.4% and 47.3%, respectively. Among the admitted patients the most common bacterial co-infection isolates were <italic>Klebsiella pneumoniae</italic> (26.9%), <italic>Acinetobacter baumannii,</italic> S<italic>taphylococcus aureus and Haemophilus parainfluenzae</italic> (11.5%) while for secondary infection <italic>Klebsiella pneumoniae</italic> (33.3%), <italic>Stenotrophomonas maltophilia</italic> (18.7%) and <italic>Pseudomonas aeruginosa (</italic>16.6%). <bold>Conclusion:</bold> The overall incidence of patients who tested positive with COVID-19 patients with bacterial co-infection and secondary infection is 3.35%. Of 2,210 patients who tested positive for COVID-19, 26 (35.1 %) had bacterial co-infection and 48 (64.9%) had secondary infection. Antibiotic use in admitted COVID-19 patients was high regardless of the low incidence of bacterial pneumonia during the first pandemic wave.