We sought to define the prevalence of tuberculin skin test (TST) positivity in a group of newly hospitalized patients, to identify risk factors for positive tests, and to examine the impact of testing on infection control practices.

Unblinded cohort study over 5 days in July 1992.

A 1,000-bed university-affiliated hospital.

All patients admitted (excluding obstetric patients and newborns) were interviewed. Patients without a history of tuberculosis (TB) or a positive TST were offered a TST with Candida and tetanus controls.

Of 346 patients offered the test, 21 (6%) had a prior history of TB or a positive TST, and 36 (10%) declined to participate; 279 of the remaining 289 completed the study. Anergy was demonstrated in 94 (33.7%) of 279 patients. New positive TSTs were identified in 19 (10.3%) of 185 nonanergic patients. Of the 19 TST-positive patients, 6 (32%) had infiltrates on chest radiographs and were evaluated for active TB. One patient was treated empirically for active TB, and five received isoniazid prophylaxis. Risk factors for a new positive TST included age (odds ratio [OR], 1.56 per decade of life; P=.021), African American race (OR, 4.81; P=.008), alcohol abuse (OR, 5.53; P=.005), and peptic ulcer disease (OR, 4.53; P=.017). Risk factors for anergy included admission to a surgical service (OR, 2.1; P=.006), current use of steroids (OR, 2.65; P=.005), and human immunodeficiency virus (HIV) infection (OR, undefined; P=.034).

Despite a high rate of anergy, routine tuberculin skin testing identified a substantial number of patients with TB infection who might otherwise have gone unrecognized.

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 investigate the infection control practices of general dentists in Ontario in 1994.

Confidential coded questionnaires were mailed to all general dental practitioners in Ontario (n=5,176), with three follow-up attempts. Data were analyzed using Pearson's chi-squared test and multiple logistic regression.

Offices of general dental practitioners in Ontario.

General dental practitioners actively involved in treating patients.

The response rate adjusted for nondelivery was 70%. A high proportion of respondents reported using gloves (always, 91.8%; sometimes, 7.8%), masks (always, 74.8%; sometimes, 21.1%), or protective eyewear (always, 83.6%; sometimes, 13%); heat sterilization of hand-pieces (83.9%); and hepatitis B (HBV) vaccination of dentists (92.3%). However, only 61.4% of respondents reported HBV vaccination of all clinical staff, and 87.7% used additional precautions for patients with human immunodeficiency virus (HIV). Significant predictors of the use of recommended infection control procedures (ie, always using gloves, masks, and eye protection; heat sterilization of handpieces; HBV vaccination for dentist and staff; and no extra precautions for patients with HIV) were age ?40 years (odds ratio [OR], 2.6), lack of concern regarding increased personal risk (OR, 2.0) or costs of infection control procedures (OR, 1.5), and knowledge of the low infectivity of HIV after a needlestick injury (OR, 2.0) and that infection control procedures for HBV are adequate for HIV (OR, 2.7).

Additional education is required to promote a more realistic perception of risk of HIV transmission in the dental office and the use of all recommended infection control practices, including Universal Precautions.

To determine whether the greater daily expense of administering total parenteral nutrition (TPN) via plastic bags changed once daily, compared to glass bottles changed thrice daily, could be offset by savings from a reduction in nosocomial infections.

The costs and potential benefits of commercially available TPN bags and TPN in glass containers were compared. Costs were computed from the viewpoint of the hospital, first in a general model and then for two specific examples, Crohn's disease and intensive-care unit (ICU) patients. The extra cost of using bags was $20 per day. The total cost of nosocomial bacteremia was estimated at $6,000. The monetary benefits of using TPN bags were $6,000XT, where XT was the percentage of nosocomial infections averted. We also considered that reduction in intravenous (IV)-line manipulation could reduce bacteremia-related mortality and computed a cost-per-life-saved ratio.

Modeling showed that TPN in bags could yield a net benefit when the absolute reduction in the daily risk of nosocomial bacteremia reached the threshold value of 0.3%. Such a reduction could not be attained in patients with Crohn's disease, and corresponded to a 50% to 60% reduction of infection rates in ICU patients. Varying the risk of mortality attributable to IV-line-related infection from 1% to 13% resulted in a cost effectiveness of using TPN bags ranging from $90,000 to $7,000 per life saved in ICU, assuming a two-thirds reduction in IV-line infections, and from $180,000 to $14,000 if the infection rate was reduced by one third.

The baseline cost-minimization analysis concluded that the extra cost of TPN bags was not justified by the extra savings. The cost-effectiveness analysis, however, found that the cost per life saved fell within the accepted range of public health interventions, provided a large fraction of infections are averted using TPN bags.

To assess factors associated with influenza vaccination of healthcare workers.

Cross-sectional survey.

University-affiliated Veterans' Affairs medical center.

Staff physicians and nurses employed by the medical center.

A mailed, self-administered questionnaire.

The response rate was 38.0%. The mean age of the respondents was 43.6 years, 71.5% were females, and 26.2% were physicians. Nearly all of the practitioners had daily or weekly contact with elderly or high-risk patients. The influenza vaccination rate of the respondents was 61.2%. More than 50% of vaccine recipients indicated that avoiding illness, protecting patients, and being able to receive the vaccine conveniently and free of charge all were very important factors influencing their decisions to receive the vaccine. Avoiding illness was rated the most important factor by 58.8% of vaccine recipients. Among vaccine nonrecipients, concern about side effects was identified as a very important factor by 36.2% and as the most important factor by 30.9%.

Vaccine recipients were significantly more likely than were vaccine nonrecipients to indicate that influenza and its complications are very serious for high-risk patients. They also were more likely to report that the vaccine is very effective, that influenza vaccination is uncommonly associated with side effects, that healthcare workers' risk for contracting influenza is higher than the general public's risk, and that it is very important for healthcare workers to receive the vaccine to decrease risk for transmission to high-risk patients. After stepwise logistic regression, variables independently associated with receipt of vaccine were age, prior receipt of vaccine, being a physician, considering the vaccine to be very effective, believing that systemic side effects are uncommon, and indicating that it is very important for healthcare workers to receive vaccine for the protection of their patients.

Many healthcare workers fail to receive influenza vaccine each year. Strategies to improve immunization levels should address concerns about vaccine safety and efficacy, barriers to vaccination including inconvenience and cost, and the reasons for targeting healthcare workers.

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.