Infection rate and colonization with antibiotic-resistant organisms in skilled nursing facility residents with indwelling devices

Abstract

The objective of this prospective surveillance study was to quantify colonization with antimicrobial-resistant organisms (AROs) and infections attributable to indwelling devices in skilled nursing facility (SNF) residents. The study was conducted in 15 SNFs in Southeast Michigan. Residents with (n=90) and without (n=88) an indwelling device were enrolled and followed for 907 resident-months. Residents were cultured monthly from multiple anatomic sites and data on infections were obtained. The device-attributable rate was calculated by subtracting the infection rate in the device group from the infection rate in the non-device group. A total of 197 new infections occurred during the study period; 87 in the device group (incidence rate [IR] =331/1,000 resident-months) and 110 infections in the non-device group (IR=171/1,000 resident-months), with a relative risk of 1.9 (95% confidence interval [CI]: 1.4-2.6). The attributable rate of excess infections among residents in the device group was 160/1,000 resident-months, with an attributable fraction of 48% (95% CI: 31-61%). Prevalence rates for all AROs were higher in the device group compared with the no-device group. The prevalence of the number of AROs per 1,000 residents cultured increased from no-device to those with only feeding tubes, followed by those with only urinary catheters and both these devices. In conclusion, the presence of indwelling devices is associated with higher incidence rates for infections and prevalence rates for AROs. Our study quantifies this risk and shows that approximately half of all infections in SNF residents with indwelling devices can be eliminated with device removal. Effective strategies to reduce infections and AROs in these residents are warranted.

Fig. 1

Distribution of antimicrobial-resistant organisms (AROs) per 1,000 residents over time (days), with the number of residents cultured at each follow-up time in the device and no-device groups shown at the bottom. a Resistant Gram-negative bacteria, b Methicillin-resistant Staphylococcus aureus, c Vancomycin-resistant Enterococci, d All antimicrobial-resistant organisms