Risk factors for bacterial infections in patients with moderate to severe COVID-19: A case-control study

Document Type



Department of Medicine; Nephrology; Internal Medicine


Adverse outcomes in coronavirus infection disease-19 (COVID-19) patients are not always due to the direct effects of the viral infection, but often due to bacterial coinfection. However, the risk factors for such bacterial coinfection are hitherto unknown. A case-control study was conducted to determine risk factors for bacterial infection in moderate to critical COVID-19. Out of a total of 50 cases and 50 controls, the proportion of cases with severe/critical disease at presentation was 80% in cases compared to 30% in controls (p < 0.001). The predominant site was hospital-acquired pneumonia (72%) and the majority were Gram-negative organisms (82%). The overall mortality was 30%, with comparatively higher mortality among cases (42% vs. 18%; p = 0.009). There was no difference between procalcitonin levels in both groups (p = 0.883). In multivariable logistic regression analysis, significant independent association was found with severe/critical COVID-19 at presentation (AOR: 4.42 times; 95% CI: 1.63-11.9) and use of steroids (AOR: 4.60; 95% CI: 1.24-17.05). Notably, 64% of controls were administered antibiotics despite the absence of bacterial coinfection or secondary infection. Risk factors for bacterial infections in moderate to critically ill patients with COVID-19 include critical illness at presentation and use of steroids. There is widespread empiric antibiotic utilization in those without bacterial infection.

Publication (Name of Journal)

Journal of Medical Virology