Incidence of nosocomial pneumonia in two intensive care units of a French University Hospital from 2016 to 2022 in the era of COVID-19 pandemic

Abstract

Background

Hospital-Acquired Pneumonia (HAP) are common in intensive care units (ICUs). The COVID-19 pandemic led to a global increase in healthcare-associated infections (HAI) among ICU patients. The aim of this study was to evaluate the trends in HAP incidence over a seven-year period of surveillance in two ICUs at a French University Hospital, and to assess the impact of COVID-19 (as well as the associated bacterial ecology).

Methods

A prospective surveillance of HAI in ICUs was conducted during the 1^st quarter of each year between 2016 and 2022 (2020: reference year). Socio-demographic, clinical and bacteriological data were collected and the incidence of HAP was calculated. Poisson regressions were done and crude and adjusted incidence rate ratio were calculated.

Results

1,797 patients were included, with 61.3% of male and a median age of 67 years. The median duration of intubation was 4 days (7 days in 2021 and 5 days in 2022). The proportion of COVID-19 patients was 45.7% in 2021 and 24.1% in 2022. Compared to 2020, the incidence of HAP increased in both 2021 [cIRR: 2.34 (95%CI: 1.30–4.23) and aIRR: 2.26 (95%CI: 1.25–4.08)] and 2022 [cIRR: 1.79 (95%CI: 0.97–3.32) and aIRR: 1.66 (95%CI: 0.90–3.07)]. The most commonly identified microorganisms were Enterobacteriaceae (42.4%), with a significantly higher incidence of HAP due to Enterobacteriaceae in COVID-19 patients.

Conclusions

These results indicate an increase of HAP incidence in 2021 and 2022, mainly caused by Enterobacteriaceae in COVID-19 patients. This trend needs to be confirmed or refuted in the post-pandemic era.