Background: There is a high predisposition of bacterial co-infection and secondary bacterial infection among patients infected with COVID-19 pneumonia, but data regarding its prevalence is lacking.

Objective: To determine the prevalence of bacterial co-infection, secondary bacterial infection and the patterns of antibiotic use of hospitalized COVID-19 patients and its impact on the clinical outcomes.

Methods: We identified 1,910 SARS-CoV-2 RT-PCR-positive patients hospitalized at the Manila Doctors Hospital from April 1, 2020 to January 31, 2022. We excluded patients with normal baseline chest imaging (n=562), patients less than 19 years old (n=7), patients transferred from other institution (n=99), patients who developed nosocomial COVID-19 infection (n=28), patients transferred to other institution (n=10) and patients who were discharged against medical advice (n=13).

Results: In the final cohort of 1,191 patients, 8.73% have bacterial co-infection while 7.05% have secondary bacterial infection. Empiric antibiotics were given in 87.5% of patients with bacterial infection and 90.48% in secondary bacterial infection. Secondary bacterial infection will increase the likelihood of: need for hemodialysis by 3.58 times; need for vasopressors by 4.23 times; need for intubation by 8.56 times; dying by 2.69 times; and prolonging the length of hospital stay by 1.99 times compared to those who have none. The over-all mortality rate is 13.69%. 

Conclusion: There is widespread antibiotic use in patients with COVID-19 pneumonia even with low prevalence of bacterial co-infection and secondary bacterial infection.