A Retrospective Analysis of Incidence and Risk Factors for the Development of Secondary Infections Following COVID-19

Abstract Introduction  The SARS-CoV-2 virus primarily affects the lungs causing a heightened immune response due to viral and host cell interaction, which prompts the release of proinflammatory cytokines and reduces the defense mechanisms of the immune system, making the patient vulnerable to secondary infections. The study aims to identify the incidence and risk factors for secondary infections developing after COVID-19. Methods and Materials  A retrospective study was conducted on 669 patients who were readmitted after COVID-19 to a tertiary care hospital. The development of secondary infections in these populations was identified. The data were collected from the medical records department. Statistical Analysis  Incidence was calculated by the ratio of the total number of patients who developed secondary infections among readmitted patients divided by the total number of readmitted patients during the study period. Univariate analysis was performed to identify the statistically significant variables that were used in logistic regression for identifying the risk factors for secondary infection. Statistical analysis was performed in SPSS version 28.0. Results and Discussion  In this study, 85 patients were found to have developed secondary infections with an incidence of 12.7%. Among the reported six infections, mucormycosis showed the highest incidence (34.1%), followed by sepsis and urinary tract infection. Nine patients developed tuberculosis as a post-COVID-19 secondary infection. General risk factors for secondary infections include male gender, presence of comorbidities such as diabetes mellitus and chronic kidney disease (CKD), intensive care unit (ICU) admission, elevated levels of interleukin-6 (IL-6) and D-dimer, and administration of steroids particularly medium-dose steroids. Conclusion  Secondary infections can occur within 43 days of COVID-19 infection for every 12.7 per 100 patients in whom there is bacterial or fungal infections. Of these secondary infections, incidence of mucormycosis and sepsis was found to be higher in our study. COVID-19-infected patients who have either of these factors such as elevated inflammatory markers (Il-6 and D-dimer), the presence of comorbidities such as diabetes mellitus and CKD, ICU admission, and the use of steroids are at risk of developing secondary infections. Through proper screening, we can prevent patients who are at risk of developing secondary infections.