Methicillin-resistant Staphylococcus aureus in a nursing home and affiliated hospital: a four-year perspective

Effects of oral amino acid supplementation on long-term-care-acquired infections in elderly patients

The very high general infection rate (IRI) observed in our Geriatric Intensive Rehabilitation Center (GIRC) led us to investigate whether patient supplementation with essential amino acids (EAAs), modulators of immuno-competence, could reduce IRI. Eighty elderly patients admitted to our GIRC (n=40; age 79.5 ± 7.71; male/female 14/26) or placebo (n=40; age 82.13 ± 6.15; male/female 13/27) were allocated to an 8 g/day oral EAAs group and were surveyed for infections (>48 h from admission) over the first month of their hospital stay. The IRI was 67% for the entire population of patients, 82.5% (33/40 patients) in the placebo group and 52% (21/40 patients) in the EAA group (p<0.02). When patients were divided into infection group (IG) and without-infection group (WIG), independently of post randomization allocation, the WIG had higher levels of serum albumin (p<0.001), blood hemoglobin (Hb) concentration (p=0.01), dietary protein (p=0.008) calorie intakes (p=0.05) but lower serum C-reactive protein (CRP) (p<0.001). The factor of CRP>0.8 mg/dl and Hb ≤ 12 in females, ≤13 in males was associated 4 times and 3.6 times risk of infection, respectively, by sex. EAAs supplementation may lower the risk of infection by 30% in the rehabilitative elderly population. CRP and blood hemoglobin levels can be considered risk markers of future infection.

Colonization of skilled-care facility residents with antimicrobial-resistant pathogens

OBJECTIVES

To determine the frequency of and risk factors for colonization of skilled-care unit residents by several antimicrobial-resistant bacterial species, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus (VRE), or extended-spectrum-beta-lactamase-producing (ESBL-producing) (ceftazidime resistant) Klebsiella pneumoniae or Escherichia coli.

DESIGN

Point-prevalence survey and medical record review.

SETTING

The skilled-care units in one healthcare facility.

PARTICIPANTS

120 skilled-care unit residents.

MEASUREMENTS

Colonization by each of the four antimicrobial-resistant pathogens during a point-prevalence survey, using rectal, nasal, gastrostomy-tube site, wound, and axillary cultures, June 1-3, 1998; 117 (98%) had at least one swab collected and 114 (95%) had a rectal swab collected. Demographic and clinical characteristics were evaluated as risk factors for colonization. All isolates were strain typed by pulsed-field gel electrophoresis of total genomic deoxyribonucleic acid.

RESULTS

Of 117 participants, 50 (43%) were culture positive for > or =1 antimicrobial-resistant pathogen: MRSA (24%), ESBL-producing K. pneumoniae (18%) or E. coli (15%), and VRE (3.5%). Of 50 residents culture positive for any of these four antimicrobial-resistant species, 13 (26%) were colonized by more than one resistant species; only three (6%) were on contact-isolation precautions at the time of the prevalence survey. Risk factors for colonization varied by pathogen: total dependence on healthcare workers (HCWs) for activities of daily living (ADLs) and antimicrobial receipt for MRSA, total dependence on HCWs for ADLs for ESBL-producing K. pneumoniae, and antimicrobial receipt for VRE. No significant risk factors were identified for colonization by ESBL-producing E. coli. Among colonized patients, there was a limited number of strain types for MRSA (24 patients, 4 strain types) and ESBL-producing K. pneumoniae (21 patients, 3 strain types), and a high proportion of unique strain types for VRE (4 patients, 4 strain types) and FSBL-producing E. coli (17 patients, 10 strain types).

CONCLUSION

A large unrecognized reservoir of skilled-care-unit residents was colonized by antimicrobial-resistant pathogens, and co-colonization by more than one target species was common. To prevent transmission of antimicrobial-resistant pathogens in long-term care facilities in which residents have high rates of colonization, infection-control strategies may need to be modified. Potential modifications include enhanced infection-control strategies, such as universal gloving for all or high-risk residents, or screening of high-risk residents, such as those with total dependence on HCWs for ADLs or recent antimicrobial receipt, and initiation of contact-isolation precautions for colonized residents.

Emerging health care-associated infections in the geriatric population

The increasing number of persons >65 years of age form a special population at risk for nosocomial and other health care-associated infections. The vulnerability of this age group is related to impaired host defenses such as diminished cell-mediated immunity. Lifestyle considerations, e.g., travel and living arrangements, and residence in nursing homes, can further complicate the clinical picture. The magnitude and diversity of health care-associated infections in the aging population are generating new arenas for prevention and control efforts.

Methicillin-resistant Staphylococcus aureus: a questionnaire and microbiological survey of nursing and residential homes in Barking, Havering and Brentwood

The study determined the policies and procedures for the control and prevention of methicillin-resistant Staphylococcus aureus (MRSA) and its prevalence among nursing and residential homes, and evaluated whether certain home characteristics such as bed size, staffing level, and type of home are related to the prevalence of MRSA. A 21-questionnaire survey, with primarily categorical responses, was mailed to the home managers of all the 121 nursing and residential homes in the district, following which a simple, stratified random sample of 28 (23.14%) homes was taken and all agreeing residents screened from multiple sites for MRSA. Seventy-seven (63.6%) homes returned a completed questionnaire, 13 (46.4%) of whom agreed to participate in the microbiological study. The response rates for returning questionnaires and agreeing to participate in the microbiological study were similar for nursing and residential homes (65% vs. 60%; 67% vs. 40%; P = 0.12; P = 0.62), respectively. Nursing homes had a mean bed size of 30 (95% Confidence Interval (CI) 17-43), not significantly different from residential homes of 23 (95% CI 18-27; P = 0.26). The nursing homes employed a mean of 8.6 (95% CI 4.7-12.5) staff nurses per home; significantly higher than residential homes with a mean of 1.6 (95% CI 0.3-2.8; P = 0.006). No significant differences in mean number of home care assistants employed per home (22.8; 95% CI 12.4-33.13; and 14.4; 95% CI 11.83-16.90; P = 0.098, for nursing and residential homes, respectively) were observed. None of the homes had employed infection control practitioners. Only four (6.8%) of the responding homes stated that MRSA was a problem. Nursing homes were not significantly more likely to have admission policies for colonized person than residential homes (10/13 vs. 40/55, P = 1.00). Of the fifty-five (71.4%) homes who had admission policies, 40 (72.7%) stated that persons colonized/infected with MRSA would not be accepted, while 12 (21.8%) would accept such persons in single-room isolation and/or barrier nursing. Greater proportions of residential homes than nursing homes would not accept admission of persons with documented MRSA colonization (30/35 vs. 4/10, P = 0.007). Four (9.1%) homes (three nursing) had identified a total of five residents colonized/infected with MRSA in 5 years prior to the survey. Two hundred and forty-six residents were screened (552 sites), two (0.81%) of whom were found to be colonized in the nose (one resident) and in the groin (two residents) with MRSA, giving a 2-month weighted point prevalence rate of 0.14% (95% CI 0.01-0.26%). We conclude that in our district the nursing staffing levels and control measures vary widely within these homes, while the prevalence of residents who are colonized/infected with MRSA is lower than in other areas. We suggest that the exclusion admission policy for MRSA positive patients should be abandoned and targeted infection control programmes be instituted.