Intensive care unit-acquired rectal colonization and subsequent infections with carbapenem-resistant bacteria: a cross-sectional study.

PURPOSE: Nosocomial infections caused by carbapenem-resistant bacteria (CRB) present a worldwide threat. We examined the incidence and clinical outcomes of ICU-acquired gastrointestinal colonization with CRB detected through routine weekly surveillance of rectal swabs.

METHODS

This retrospective study included adult patients admitted to the ICU between January 1, 2020 and December 31, 2022, whose rectal swab cultures yielded CRB colonization after at least 72 h of ICU admission.

RESULTS

Of 4,673 eligible patients, 493 had at least one positive rectal swab culture for CRB (prevalence 10.5%) after a mean of 17.8 days from ICU admission. The most common CRB species was Klebsiella pneumoniae (41.8%), followed by Acinetobacter baumannii (32.3%), Pseudomonas aeruginosa (21.3%) and Escherichia coli (8.1%). Following colonization, 240 patients (48.7%) developed CRB infections after a mean of 11.4 days and 29.2 days from the first positive rectal culture and from ICU admission, respectively. The overall agreement between the baseline rectal and final cultures was 82.1%. CRB-infected patients had higher frequencies of burns at baseline (p < 0.001), carbapenem (p = 0.015) and colistin (p < 0.001) use during ICU stay, need for intubation (p = 0.002) and nasogastric tube (p = 0.021), prolonged ICU stay (p < 0.001), and mortality (p = 0.006).

CONCLUSION

Our findings showed that nearly one in every 10 ICU patients acquired CRB colonization despite preventive efforts, ending up with CRB infections in nearly half.