Secondary Infections in Intensive Care Unit Patients in the COVID-19 Pandemic – Retrospective Study of the Incidence, Patterns, Risk Factors, and Outcomes

Abstract

Introduction: The COVID-19 pandemic has raised significant concerns for secondary infections. In the second wave, there was an unprecedented epidemic of secondary invasive fungal infections. This study analyses the prevalence, details, risk factors, and outcomes of secondary infections in COVID-19 patients in a tertiary intensive care unit (ICU) in India. Materials and Methods: Retrospective analysis of secondary infections in ICU COVID-19 patients between April 2021 and June 2021. Demographic data, secondary bacterial and fungal infections, immunomodulator therapy, antimicrobial susceptibility data, and clinical outcomes were analyzed. Results: 71/238 (29.83%) ICU patients developed secondary bacterial and fungal infections. Mortality with secondary infections was significantly higher (80.28% [P < 0.05]), compared to an overall ICU mortality of 51.68%. In patients with secondary infections, 59.66% were referred from other hospitals after receiving initial treatment and 52.10% had received various immunomodulatory therapies. Prolonged mechanical ventilation, indwelling central venous, and urinary catheters had higher secondary infection rates and higher mortality. Gram-negative bacteria were isolated in 85.91% and 32.39% had fungal isolates. Klebsiella pneumoniae, followed by Acinetobacter baumannii, were the predominant bacteria. Candida spp., followed by Mucormycosis, were the predominant fungal pathogens. Multi-drug resistant (MDR) infections were common (73.28%). 49.3% of secondary infection patients had polymicrobial infections, including fungal infections, with a higher mortality of 82.86%. Conclusions: There was a high incidence of secondary MDR bacterial and fungal infection, including Mucormycosis, in ICU COVID-19 patients, with higher mortality. Risk factors included immunomodulators such as tocilizumab, bevacizumab, and itolizumab, steroids, invasive tubes and catheters, and prolonged ICU and hospital stay. By uniform steroids, we meant the recommended use of moderate-to-high dose steroids for all patients with severe COVID-19 pneumonia (recovery trial), invasive tubes and catheters, and prolonged ICU and hospital stay.