To describe an outbreak of trimethoprim-sulfamethoxazole (cotrimoxazole)–resistant and methicillin-resistant Staphylococcus aureus (CMRSA) in a unit housing patients infected with the human immunodeficiency virus (HIV).

Prospective study involving patients colonized or infected with CMRSA.

15 hospitalized patients with cultures positive for CMRSA.

Isolates of CMRSA were collected and characterized. Molecular typing of the epidemic strains was carried out after total DNA extraction by restriction endonuclease analysis and random amplification of polymorphic DNA.

The epidemic was brought under control with the reinforcement of nosocomial transmission measures and with systematic nasal decontamination with mupirocin of all patients admitted to the HIV unit. Molecular typing techniques showed the existence of two epidemic strains: strain A was present in the 12 patients admitted to the HIV unit and strain B in the remaining 3 patients hospitalized elsewhere.

Cotrimoxazole may no longer be a reliable and effective alternative for glycopeptides in patients with infection caused by MRSA strains, and HIV units should be particularly alert for CMRSA strains.

To study the possible role of contaminated environmental surfaces as a reservoir of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals.

A prospective culture survey of inanimate objects in the rooms of patients with MRSA.

A 200-bed university-affiliated teaching hospital.

Thirty-eight consecutive patients colonized or infected with MRSA. Patients represented endemic MRSA cases.

Ninety-six (27%) of 350 surfaces sampled in the rooms of affected patients were contaminated with MRSA. When patients had MRSA in a wound or urine, 36% of surfaces were contaminated. In contrast, when MRSA was isolated from other body sites, only 6% of surfaces were contaminated (odds ratio, 8.8; 95% confidence interval, 3.725.5; Pく.0001). Environmental contamination occurred in the rooms of 73% of infected patients and 69% of colonized patients. Frequently contaminated objects included the floor, bed linens, the patient's gown, overbed tables, and blood pressure cuffs. Sixty-five percent of nurses who had performed morning patient-care activities on patients with MRSA in a wound or urine contaminated their nursing uniforms or gowns with MRSA. Forty-two percent of personnel who had no direct contact with such patients, but had touched contaminated surfaces, contaminated their gloves with MRSA.

We concluded that inanimate surfaces near affected patients commonly become contaminated with MRSA and that the frequency of contamination is affected by the body site at which patients are colonized or infected. That personnel may contaminate their gloves (or possibly their hands) by touching such surfaces suggests that contaminated environmental surfaces may serve as a reservoir of MRSA in hospitals.

To evaluate the effectiveness of specific infection control measures on the incidence of Clostridium difficile-associated diarrhea (CDAD) and to identify risk factors for its development.

370-bed, tertiary-care teaching hospital with approximately 12,000 to 15,000 admissions per year.

Several infection control measures were implemented in 1991 and 1992, and the attack rates of CDAD were calculated quarterly. Antibiotic use for 1988 through 1993 was analyzed. A case-control study was conducted from January 1992 to December 1992 to identify risk factors for acquisition of CDAD.

From 1989 to 1992, the attack rate of CDAD increased from 0.49% to 2.25%. An increase in antibiotic use preceded the rise in the incidence of CDAD in 1991. Despite implementation of various infection control measures, the attack rate decreased to 1.32% in 1993, but did not return to baseline. Ninety-two cases and 78 controls (patients with diarrhea but with negative toxin assay) were studied. By univariate analysis, history of prior respiratory tract infections (odds ratio [OR], 3.6; 95% confidence interval [CI95], 1.2-10.4), the number of antibiotics, and the duration of exposure to second-generation cephalosporins (OR, 3.55; CI95, 1.47-9.41) and to ciprofloxacin (OR, 7.27; CI95, 1.13-166.0) were related significantly to the development of CDAD. By stepwise logistic regression analysis, only exposure to antibiotics and prior respiratory tract infections (P=.0001 and .0203, respectively) were found to be significant.

Antibiotic pressure might have contributed to failure of infection control measures to reduce the incidence of CDAD to baseline.

To determine the knowledge of rubella immune status among practicing obstetrician-gynecologists in the United States and of rubella immunity policies covering healthcare workers in the obstetric-care office setting.

Mailed survey questionnaire, August through December 1994.

Physicians from multiple-practice sites including private office, public institution, university or teaching hospital, and closed panel health maintenance organization settings.

3,302 practicing obstetrician-gynecologists, chosen by a systematic random sample from the AMA national physician database.

Participants were defined as rubella immune if they reported knowledge of prior rubella vaccination or positive antibody titer. Knowledge of a policy for documenting rubella immunity among employees in the office-based practice setting also was assessed.

Questionnaires were returned from 50% (1,666) of the 3,302 surveyed, and 96% (1,599) were evaluable. Approximately 20% (304/1,599) of the responding obstetrician-gynecologists did not have knowledge of documented rubella immunity, and the majority of office-based practices did not require documentation of rubella immunity in the following groups: physicians, 66% (723/1,094); office nurses, 62% (666/1,070); and other office staff, 69% (728/1,063). Sixty-two percent (993/1,599) of responding physicians had individual rubella serologies performed, with 916 known to be positive, 53 reported negative, and 24 reported unknown. Fifty-seven percent (918/1,599) reported receiving monovalent rubella vaccine or trivalent measles-mumps-rubella vaccine. Multiple logistic regression analysis revealed the following to be independent predictors of positive immune status among respondents: female gender (odds ratio [OR], 2.4; 95% confidence interval [CI95], 1.8-3.1), medical school graduation since 1980 (OR, 2.6; CI95, 2.0-3.3), providing obstetric or fertility services (OR, 1.5; CI95, 1.2-1.9), and group practice setting ≥5 physicians; OR, 1.2; CI95, 1.1-14).

Nationally, nearly one of every five practicing obstetricians may not have documented rubella immunity, and the majority of office-based practices have no system for assuring such immunity. Rubella immunity should extend beyond the hospital setting, with consideration for requiring rubella immunity as a condition for employment. Methods for effective implementation and documentation of current guidelines need to be addressed, particularly in the office setting.

To investigate a case of nosocomial legionellosis, identify pathways of transmission, and effect control of the environmental source.

Case investigation and environmental culture surveillance.

A 720-bed university teaching hospital.

A ventilator-dependent 66-year-old male developed nosocomial pneumonia due to Legionella pneumophila serogroup 6 after 3 months in an intensive-care unit (ICU). The patient had no intake of potable water except for ice chips from an ice machine in the ICU.

Cultures revealed L pneumophila serogroup 6 in the ice (4.3 colony-forming units/mL) and ice machine cold water (too numerous to count). Cultures from adjacent hot and cold taps, plus taps located near the patient, all were negative; ice machines and cold water on seven other patient units also were negative. Only sterile water had been used for tube feedings, mouth care, suctioning, and ventilator humidification. Hospital hot water previously had been colonized with L pneumophila serogroup 6, but all surveillance water cultures had been negative since chlorination of the hot-water system began the previous year; cold-water cultures had never before grown Legionella.

The ice machine was disinfected with a 2-hour flush of 2.625% sodium hypochlorite. The supply line to the ice machine was replaced, and the cold-water pipe from the floor below was treated with 83 ppm sodium hypochlorite for 48 hours. All follow-up surveillance cultures of the ice machine remained negative through mid-1996. No additional cases of nosocomial legionellosis occurred.

Ice machines may be reservoirs of L pneumophila in hospitals. Both ice and water dispensed from these machines may be contaminated, and nosocomial transmission may occur. Successful long-term decontamination and control can be accomplished with shock chlorination.

To use a serum and salt challenge in narrow-lumen carriers to evaluate a 10% ethylene oxide plus 90% hydrochlorofluorocarbon (EO-HCFC) sterilant mixture in a retrofitted 12/88 sterilizer as an alternative to the banned chlorofluorocarbon-ethylene oxide (EO) sterilant mixture.

An EO-HCFC sterilizing gas mixture in a retrofitted 12/88 sterilizer was compared to 100% ethylene oxide (100% EO) sterilizing gas to determine its relative ability to kill seven different bacteria (Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Bacillus subtilis spores, Bacillus stearothermophilus spores, Bacillus circulans spores, and Mycobacterium chelonei) in the presence or absence of a combined 10% serum and 0.65% salt challenge using both penicylinders (PC) and long narrowlumen (LU) carriers.

The EO-HCFC sterilant mixture (96% sterile carriers) was equivalent to the 100% EO sterilant (98% sterile carriers) for killing vegetative organisms, as well as spore suspensions, on the 27 PC and 27 LU carriers in the absence of serum and salt. In the presence of serum and salt, the EO-HCFC sterilant mixture was markedly better than the 100% EO sterilant at reducing the bacterial load on the 63 PC carriers (95% vs 62% sterile PC carriers, respectively), whereas both sterilizers were equivalent for the 63 LU carriers (49% vs 40% sterile LU carriers, respectively). Of the seven test organisms, E faecalis, B subtilis, B stearothermophilus, and B circulans were the most difficult to kill for both PC and LU carriers when serum and salt were present.

The data presented in this report indicate that the EO-HCFC sterilant mixture is an effective alternative for gas sterilization. Indeed, the efficiency of bacterial killing for the EO-HCFC sterilant mixture was similar to that achieved by the 12/88 EO-CFC sterilant mixture.

To evaluate the efficacy of the AbTox Plazlyte Sterilization System against selected microbial species using inoculated carriers and surgical instruments.

The microbiology laboratory of a 700-bed adult tertiary-care hospital.

The study was conducted in two phases. In phase 1, microorganisms were inoculated to various metal, paper, plastic, and glass carriers, as well as surgical equipment, and processed in cycle II of the AbTox sterilizer. Phase 2 compared AbTox cycle III with ethylene oxide sterilization using stainless steel washers, penicylinders, and surgical equipment. In both phases, cultures of equipment and carriers were obtained after processing. The phenotypic profiles and antibiograms of positive cultures were compared to the original inoculate to rule out the possibility of contamination.

Of a total of 350 paper carriers, 375 metal washers, and 234 pieces of equipment processed in cycle II and using trypticase soy broth as the inoculating medium, 123 metal washers (32%) and 8 instruments (3%) failed to be sterilized. Similar failures were noted with cycle III. The presence of either salt or protein adversely affected the system's ability to sterilize in either cycle.

Further studies are needed to evaluate the extent to which salt or organic material compromise low-temperature gas-plasma sterilization. Meanwhile, users should exercise caution and use care in the cleaning of instruments that will be processed in the plasma-based sterilization technologies