The point prevalence and associated factors of nasal methicillin-resistant Staphylococcus aureus colonisation in eight geriatric hospitals in Korea

Impact of nursing home residence on hospital epidemiology of meticillin-resistant Staphylococcus aureus: a perspective from Asia

In a Singapore hospital practising meticillin-resistant Staphylococcus aureus (MRSA) admission screening, the relative risk for MRSA colonization for those admitted from nursing homes was 6.89 (95% confidence interval: 5.74-8.26; 41% of 190 vs 6.0% of 14,849). However, the MRSA burden on admission attributable to nursing home residence was low (6.9%). Risk factors independently associated with MRSA colonization in patients admitted from nursing homes were previous hospital admissions, broken skin, prior use of antibiotics and Chinese ethnicity. Low rates of nursing home use means that the overall impact of nursing home residence on MRSA in our hospital is low.

New acquisition of antibiotic-resistant organisms in skilled nursing facilities

The epidemiology of new acquisition of antibiotic-resistant organisms (AROs) in community-based skilled nursing facilities (SNFs) is not well studied. To define the incidence, persistence of, and time to new colonization with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and ceftazidime-resistant (CAZ(r)) and ciprofloxacin-resistant (CIP(r)) Gram-negative bacteria (GNB) in SNFs, SNF residents were enrolled and specimens from the nares, oropharynx, groin, perianal area, and wounds were prospectively cultured monthly. Standard microbiological tests were used to identify MRSA, VRE, and CAZ(r) and CIP(r) GNB. Residents with at least 3 months of follow-up were included in the analysis. Colonized residents were categorized as having either preexisting or new acquisition. The time to colonization for new acquisition of AROs was calculated. Eighty-two residents met the eligibility criteria. New acquisition of AROs was common. For example, of the 59 residents colonized with CIP(r) GNB, 28 (47%) were colonized with CIP(r) GNB at the start of the study (96% persistent and 4% intermittent), and 31 (53%) acquired CIP(r) GNB at the facility (61% persistent). The time to new acquisition was shortest for CIP(r) GNB, at a mean of 75.5 days; the time to new acquisition for MRSA was 126.6 days (P = 0.007 versus CIP(r) GNB), that for CAZ(r) was 176.0 days (P = 0.0001 versus CIP(r) GNB), and that for VRE was 186.0 days (P = 0.0004 versus CIP(r) GNB). Functional status was significantly associated with new acquisition of AROs (odds ratio [OR], 1.24; P = 0.01). New acquisition of AROs, in particular CIP(r) GNB and MRSA, is common in SNFs. CIP(r) GNB are acquired rapidly. Additional longitudinal studies to investigate risk factors for ARO acquisition are required.

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

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.

Poor functional status as a risk factor for surgical site infection due to methicillin-resistant Staphylococcus aureus

OBJECTIVE

To identify risk factors for surgical site infection (SSI) due to methicillin-resistant Staphylococcus aureus (MRSA).

DESIGN

Prospective case-control study.

SETTING

One tertiary and 6 community-based institutions in the southeastern United States.

METHODS

We compared patients with SSI due to MRSA with 2 control groups: matched uninfected surgical patients and patients with SSI due to methicillin-susceptible S. aureus (MSSA). Multivariable logistic regression was used to determine variables independently associated with SSI due to MRSA, compared with each control group.

RESULTS

During the 5-year study period, 150 case patients with SSI due to MRSA were identified and compared with 231 matched uninfected control patients and 128 control patients with SSI due to MSSA. Two variables were independently associated with SSI due to MRSA in both multivariable regression models: need for assistance with 3 or more activities of daily living (odds ratio [OR] compared with uninfected patients, 3.97 [95% confidence interval {CI}, 2.18-7.25]; OR compared with patients with SSI due to MSSA, 3.88 [95% CI, 1.91-7.87]) and prolonged duration of surgery (OR compared with uninfected patients, 1.98 [95% CI, 1.11-3.55]; OR compared with patients with SSI due to MSSA, 2.33 [95% CI, 1.17-4.62]). Lack of independence (ie, poor functional status) remained associated with an increased risk of SSI due to MRSA after stratifying by age.

CONCLUSIONS

Poor functional status was highly associated with SSI due to MRSA in adult surgical patients, regardless of age. A patient's level of independence can be easily determined, and this information can be used preoperatively to target preventive interventions.