We investigated a large outbreak of community-onset methicillin-resistant Staphylococcus aureus (MRSA) infections in southwestern Alaska to determine the extent of these infections and whether MRSA isolates were likely community acquired.

Retrospective cohort study.

Rural southwestern Alaska.

All patients with a history of culture-confirmed S. aureus infection from March 1, 1999, through August 10, 2000.

More than 80% of culture-confirmed S. aureus infections were methicillin resistant, and 84% of MRSA infections involved skin or soft tissue; invasive disease was rare. Most (77%) of the patients with MRSA skin infections had communityacquired MRSA (no hospitalization, surgery, dialysis, indwelling line or catheter, or admission to a long-term-care facility in the 12 months before infection). Patients with MRSA skin infections were more likely to have received a prescription for an antimicrobial agent in the 180 days before infection than were patients with methicillin-susceptible S. aureus skin infections.

Our findings indicate that the epidemiology of MRSA in rural southwestern Alaska has changed and suggest that the emergence of community-onset MRSA in this region was not related to spread of a hospital organism. Treatment guidelines were developed recommending that beta-lactam antimicrobial agents not be used as a first-line therapy for suspected S. aureus infections.

Although alcohol-based hand rinses and gels have recommended application times of 30 to 60 seconds, healthcare workers usually take much less time for hand hygiene. We compared the efficacies of four alcohol-based hand rubs produced in Europe (hand rinses A, B, and C and one gel formulation) with the efficacy of the European Norm 1500 (EN 1500) reference waterless hand antisepsis agent (60% 2-propanol) at short application times.

Comparative crossover study.

Infection Control Program laboratory of a large tertiary-care teaching hospital.

Twelve healthy volunteers.

Measurement of residual bacterial counts and log reduction factors following inoculation of fingertips with Staphylococcus aureus American Type Culture Collection (ATCC) 6538, Pseudomonas aeruginosa ATCC 15442, and a clinical isolate of Enterococcus faecalis.

All hand rinses satisfied EN 1500 standards following a single application for 15 and 30 seconds, but reduction factors for the gel formulation were significantly lower for all tested organisms (all P < .025).

Under stringent conditions similar to clinical practice, all three hand rinses proved to be more efficacious than the marketed alcohol-based gel in reducing bacterial counts on hands. Further studies are necessary to determine the in vivo efficacy of alcohol-based gels and whether they are as efficacious as alcohol-based rinses in reducing the transmission of nosocomial infections.

Aspergillus fumigatus is a major pathogen causing nosocomial infections. Hospital outbreaks of invasive aspergillosis have been associated with the renovation and construction of buildings. Building construction work for fire safety upgrading was undertaken during a 16-week period in 2001 at Box Hill Hospital. This study was designed to examine the effect of construction on invasive aspergillosis when using standard and additional protective measures.

Baseline air sampling was conducted in 18 areas. The validity of the air sampling was assessed by comparing the ability of two air samplers to detect Aspergillus conidia. Surveillance of nosocomial Aspergillus infection was conducted by reviewing the records of patients with a sputum culture positive for Aspergillus and those prescribed amphotericin or itraconazole for the period of construction activity and the same period the previous year.

Aspergillus was isolated infrequently and there was no statistically significant difference in the levels of viable pathogenic fungi between areas where construction work was undertaken and areas where it was not undertaken. A moderate agreement was observed between the two air samplers (kappa = 0.4; P < .05). There was no difference in the incidence of invasive aspergillosis between 2000 and 2001 (incidence density ratio, 1.2; 95% confidence interval, 0.3 to 4.1).

The influence of construction work performed with protective measures needs to be examined in an environment with higher levels of airborne fungi to confirm the findings of this study (Infect Control Hosp Epidemiol 2003;24:472-476).

To describe a longitudinal profile of resistance to beta-lactam antimicrobials among isolates of Staphylococcus aureus at a large university teaching hospital and to evaluate the impact of the methicillin resistance phenotype on resistance trends for non-beta-lactam antimicrobials.

Retrospective evaluation of antimicrobial susceptibility data for all 17,287 S. aureus isolates obtained from January 1986 through December 2000.

The University of Chicago Hospitals, a family of tertiary-care, university-affiliated hospitals in Chicago, Illinois, consisting of 547 adult and pediatric beds.

The annual rate of resistance to methicillin increased from 13% in 1986 to 28% in 2000 (P < .001) and has not plateaued. For each non-beta-lactam antimicrobial tested, the annual rates of resistance were far higher among methicillinresistant S. aureus (MRSA) isolates than among methicillin-susceptible S. aureus (MSSA) isolates. The annual rates of resistance to the macrolide, lincosamide, and streptogramin (MLS) antimicrobials erythromycin and clindamycin increased among MSSA isolates (P < .01), but remained lower than 20%. Resistance to the MLS antimicrobials was higher among MRSA isolates (higher than 60%), but the annual rate decreased significantly during the study (P < .01).

The prevalence of methicillin resistance among S. aureus isolates has continued to increase; resistance to non-beta-lactam antimicrobials is far more common among MRSA isolates. Recent decreases in the proportion of MRSA isolates resistant to non-beta-lactam antimicrobials suggest important changes in the epidemiology of this pathogen.

To demonstrate the effectiveness of the Charlson weighted index of comorbidity (WIC) for controlling comorbidity in prospective studies focusing on mortality in patients with Staphylococcus aureus bacteremia (SAB).

Cohort study.

Two tertiary-care, university-affiliated hospitals in France.

One hundred sixty-six inpatients 18 years or older consecutively diagnosed with SAB from May 15, 2001, to May 15, 2002.

Patients were prospectively assessed and cases were followed by the infectious diseases consult service at least 3 months after effective antibiotic therapy completion. The Charlson WIC was computed and dichotomized into scores of fewer than 3 points and 3 or more points. Bacteremia source, acute complication due to SAB acquisition in the ICU, and inappropriate empiric antibiotic therapy were recorded. The endpoint was death due to SAB and overall mortality.

In univariate analysis, the Charlson WIC was able to predict overall mortality and S. aureus-related death. The following variables were found to be independently predictive of mortality due to SAB using the Cox model: an acute complication due to S. aureus (OR, 8.9; CI95, 4 to 19.7; P < .001), a Charlson WIC score of 3 or more (OR, 3; CI95, 1.3 to 5.5; P = .006), and age (OR, 1.04; CI95, 1.009 to 1.07; P < .01).

Comorbidity contributes to death in patients with SAB. The Charlson WIC is a good predictor of mortality in this population and may be a useful instrument to control comorbidity in studies aiming to investigate risk factors for death due to bacteremia.

To characterize occupationally acquired human immunodeficiency virus (HIV) infection detected through case surveillance efforts in the United States.

National surveillance systems, based on voluntary case reporting.

Healthcare or laboratory (clinical or research) settings.

Healthcare workers, defined as individuals employed in healthcare or laboratory settings (including students and trainees), who are infected with HIV.

Review of data reported through December 2001 in the HIV/AIDS Reporting System and the National Surveillance for Occupationally Acquired HIV Infection.

Of 57 healthcare workers with documented occupationally acquired HIV infection, most (86%) were exposed to blood, and most (88%) had percutaneous injuries. The circumstances varied among 51 percutaneous injuries, with the largest proportion (41%) occurring after a procedure, 35% occurring during a procedure, and 20% occurring during disposal of sharp objects. Unexpected circumstances difficult to anticipate during or after procedures accounted for 20% of all injuries. Of 55 known source patients, most (69%) had acquired immunodeficiency syndrome (AIDS) at the time of occupational exposure, but some (11%) had asymptomatic HIV infection. Eight (14%) of the healthcare workers were infected despite receiving postexposure prophylaxis (PEP).

Prevention strategies for occupationally acquired HIV infection should continue to emphasize avoiding blood exposures. Healthcare workers should be educated about both the benefits and the limitations of PEP, which does not always prevent HIV infection following an exposure. Technologic advances (eg, safety-engineered devices) may further enhance safety in the healthcare workplace

To examine the impact of introduction of an alcohol-based hand rub on hand hygiene knowledge and compliance and hand colonization of healthcare workers (HCWs) in a long-term-care facility (LTCF).

Two floors of an LTCF participated. Ward A used the hand rub as an adjunct to soap and water; ward B was the control. HCWs' hands were cultured using the bag-broth technique for Staphylococcus aureus, gram-negative bacilli (GNB), Candida, and vancomycin-resistant enterococci (VRE). HCWs completed a questionnaire at baseline and after an educational intervention and introduction of rub.

Hand hygiene practices, knowledge, and opinions did not change after the educational or rub intervention. Ward A HCWs thought that the rub was faster (P = .002) and less drying (P = .04) than soap. Hand hygiene frequency did not differ at baseline between the two floors, but increased on ward A by the end of the study (P = .04). HCWs were colonized frequently with GNB (66%), Candida (41%), S. aureus (20%), and VRE (9%). Although colonization did not change from baseline on either ward, the rub was more effective in clearing GNB (P = .03) and S. aureus (P = .003). Nosocomial infection rates did not change.

The alcohol-based hand rub was a faster, more convenient, less drying method of hand hygiene for HCWs in an LTCF, and it improved compliance. Although microbial colonization did not change, the rub was more efficacious in removing pathogens already present on the hands of HCWs.

To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization among patients presenting for hospital admission and to identify risk factors for MRSA colonization.

Surveillance cultures were performed at the time of hospital admission to identify patients colonized with S. aureus. A case-control study was performed to identify risk factors for MRSA colonization.

A tertiary-care academic medical center.

Adults presenting for hospital admission (N = 974).

S. aureus was isolated from 205 (21%) of the patients for whom cultures were performed. Methicillin-sensitive S. aureus was isolated from 179 (18.4%) of the patients, and MRSA was isolated from 26 (2.7%) of the patients. All 26 MRSA-colonized patients had been admitted to a healthcare facility in the preceding year, had at least one chronic illness, or both. In multivariate analyses comparing MRSA-colonized patients with control-patients, admission to a nursing home (odds ratio [OR], 16.5; 95% confidence interval [CI95], 1.4 to 192.1; P = .025) or a hospitalization of 5 days or longer during the preceding year (OR, 3.91; CI95, 1.1 to 13.9; P = .035) were independent predictors of MRSA colonization.

Patients colonized with MRSA admitted to this hospital likely acquired the organism during previous encounters with healthcare facilities. There was no evidence that MRSA colonization occurs commonly among low-risk individuals in this community. These data suggest that evaluation of recent healthcare exposures is essential if true community acquisition of MRSA is to be confirmed.

To assess the prevalence of HIV antiretroviral resistance among source patients for occupational HIV exposures.

Blood and data (eg, stage of HIV, previous antiretroviral drug therapy, and HIV RNA viral load) were collected from HIV-infected patients who were source patients for occupational exposures.

Seven tertiary-care medical centers in five U.S. cities (San Diego, California; Miami, Florida; Boston, Massachusetts; Albany, New York; and New York, New York [three sites]) during 1998 to 1999.

Sixty-four HIV-infected patients who were source patients for occupational exposures.

Virus from 50 patients was sequenced; virus from 14 patients with an undetectable (ie, < 400 RNA copies/mL) viral load could not be sequenced. Overall, 19 (38%) of the 50 patients had primary eenotypic mutations associated with resistance to reverse transcriptase or protease inhibitors. Eighteen of the 19 viruses with primary mutations and 13 wild type viruses were phenotyped by recombinant assays; 19 had phenotypic resistance to at least one antiretroviral agent. Of the 50 source patients studied, 26 had taken antiretroviral agents in the 3 months before the occupational exposure incident. Sixteen (62%) of the 26 drug-treated patients had virus that was phenotypically resistant to at least one drug. Four (17%) of 23 untreated patients had phenotypically resistant virus. No episodes of HIV transmission were observed among the exposed HCWs.

There was a high prevalence of drug-resistant HIV among source patients for occupational HIV exposures. Healthcare providers should use the drug treatment information of source patients when making decisions about postexposure prophylaxis.