Infections due to carbapenemase-producing bacteria, clinical burden, and impact of screening strategies on outcome

Abstract

Objectives

To characterize the risk factors, impact of screening, and clinical burden of colonization and/or infection by carbapenemase-producing bacteria (CPB) in hospitalized patients.

Method

Retrospective study in a tertiary care hospital between 2008 and 2016.

Results

Among 88 included patients, 41% were colonized, 59% developed an infection, and 69% of all cases were hospital-acquired. Risk factors for CPB contamination included recent invasive medical device (94% of patients), antibiotic therapy (82%), travel abroad (17%), and hospitalization (> 50%) with 80% of all patients with underlying chronic condition. Intestinal carriage represented 89% of all colonization cases and 50% of infections were located in the urinary tract. The recent use of mechanical ventilation devices was significantly more observed in infected patients than colonized patients. The most frequent CPB was Klebsiella pneumoniae and the most frequent carbapenemase was OXA-48. Overall mortality rate was 19%. Prevalence of CPB detection in intensive care units (ICU) based on systematical rectal screen swab upon admission remained < 0.5%. The infected/colonized ratio (CPB colonization cases evolving into an infection) was 23%. The time between CPB infection diagnosis and start of appropriate antimicrobial therapy increased from 1 day in previously screened patients with positive CPB to 4 days in patients with previous negative or absent screening.

Conclusion

Our results emphasize the importance of CPB screening in all ICU patients and in at-risk patients hospitalized in other units, to allow earlier adequate antibiotic therapy in case of infection which occurred in 23% of the colonized patients.