Bed occupancy and nosocomial infections in the intensive care unit: A retrospective observational study in a tertiary hospital.

Background. Healthcare-associated infections (HAI) are a major problem globally, contributing to prolonged hospital admissions and poor outcomes. Objective. To examine HAI incidence and risk factors in an intensive care unit (ICU) during high v. low occupancy periods. Methods. This retrospective, descriptive analysis investigated HAI incidence among adult patients admitted to the ICU at Chris Hani Baragwanath (CHBH) during a high (H2019) and low (L2020) occupancy. Data were extracted from the clinical records of 440 eligible patients. Results. We found an increased risk of HAI during H2019 compared with L2020 (relative risk (RR) 1.42, 95% confidence interval (CI) 1.03 - 1.94). The overall frequency density of HAI was 25/1 000 ICU days. There was no difference in the distribution of the site of infection (blood v. other) (p=0.27) or bacterial category (Gram stain) (p=0.62). Five organisms accounted for 89% of pathogens: Klebsiella (26%), Staphylococcus (21%), Acinetobacter (16%), Candida (16%) and Enterobacter (10%). The incidence of multidrug-resistant/extensively drug-resistant (MDR/XDR) organisms was 4.2-fold higher (95% CI 1.3 - 13.4) during H2019 compared with L2020. Logistic regression analysis revealed two independent predictors of nosocomial infection: ICU length of stay (odds ratio (OR) 1.12, 95% CI 1.02 - 1.22) and intercostal drain duration in days (OR 1.27, 95% CI 1.09 - 1.47). Conclusion. High occupancy in the ICU was associated with an increased risk of HAI and a greater incidence of MDR and XDR pathogens. Increasing ICU length of stay and invasive device duration were independent predictors of HAI. [ABSTRACT FROM AUTHOR]