Rectal versus groin screening for multidrug-resistant organisms: pathogen-specific diagnostic yield in a tertiary-care hospital.

OBJECTIVE

To evaluate the pathogen-specific diagnostic yield of rectal and groin screening sites in a hospital-based multidrug-resistant organism (MDRO) surveillance program.

DESIGN

Prospective observational surveillance study.

SETTING

Tertiary academic hospital in Northern Greece.

PATIENTS: Hospitalized patients undergoing active MDRO screening based on predefined infection prevention and control criteria.

METHODS

A pathogen-focused analysis was conducted using data from a prospective MDRO surveillance program between October 2024 and January 2025. Screening swabs were obtained from the rectum and groin. Target organisms included multidrug-resistant (MDR) Klebsiella pneumoniae, Pseudomonas aeruginosa, vancomycin-resistant enterococci (VRE), Candida auris, and Acinetobacter spp. Pathogen-specific detection yields were calculated for each anatomical site.

RESULTS

Among 1,206 screening swabs, 308 (25.5%) were positive for at least one MDRO. Rectal swabs detected 95.8% of Klebsiella pneumoniae (K. pneumoniae) (92/96), 100% of VRE (59/59), and 66.7% of Pseudomonas aeruginosa (46/69). In contrast, 88.9% of Candida auris cases (24/27) were identified exclusively from groin swabs. Reliance on rectal screening alone would have missed nearly 90% of Candida auris carriers, whereas groin-only screening would have failed to detect most K. pneumoniae and all VRE carriers.

CONCLUSIONS

Anatomical site selection critically influences MDRO surveillance sensitivity. Rectal screening is optimal for MDROs colonizing the gastrointestinal tract, whereas groin sampling is essential for detecting Candida auris. Pathogen-targeted, site-specific surveillance strategies may substantially improve detection efficiency and optimize infection prevention efforts in high-prevalence hospital settings.