The mechanical/chemical infectious waste disposal system (IWDS), model Z-5000 HC, manufactured by Medical SafeTEC Inc. (Indianapolis, Indiana) was evaluated for its ability to disinfect biomedical waste.

The IWDS was operated with a sodium hypochlorite solution and tested with loads consisting of microbial cultures and blood. During and after processing, samples of liquid, milled solid waste, and leachate were collected to determine the efficacy of disinfection and the chemical by-products released. An inactivation factor was calculated. Aerosol emission was studied. All tests were done in triplicate.

Our results showed the expected level of disinfection (inactivation factor >5 log,,) for all tests carried out with Bacillus subtilis, Enterococcus faecalis, Candida albicans, and Serratia marcescens, and for most of the tests with Mycobacterium fortuitum and bacteriophages 0X174 and f2. Further tests performed in the absence of blood resulted in an inactivation factor 35 log,, for all tests with M fortuitum, but not for those of the milled solids with bacteriophage f2. Aerosols were found to escape the apparatus when the IWDS was operated in the absence of chlorine. The liquid effluent contained an average of 17,600, and 15 mg/l of free chlorine, chloramines, and trihalomethanes (THM), respectively. The air effluent contained 1.1 mg/m3 of total chlorine and 1.4 kg/m3 of THM.

Under our study conditions and except for certain tests with bacteriophage f2, the IWDS reduced the microbial populations tested by a factor of 5 log10. The aerosol dispersion problem remains to be solved, and the significance of the chemical by-products released will require further investigation.

To study an increase of antimicrobial-resistant Acinetobacter baumannii and to assess reasons for the delayed detection of this increase.

Review of medical, laboratory, and infection control records. Plasmid profile analysis of available A baumannii isolates.

A 340-bed trauma and intensive care hospital in Detroit, Michigan.

The number of hospitalized patients with resistant A baumannii increased during late 1989 and early 1990: 4 in September, 10 in October, 12 in November, 18 in December, and 23 in January (chi square for trend = 14.6, p= .0001). Forty-four (66%) of the 67 patients culture-positive for resistant A baumannii had respiratory tract colonization or infection. Of 11 resistant isolates, 6 had a similar plasmid profile and 5 had no plasmids. Under the hospital's targeted surveillance system, only positive cultures from blood or wounds were investigated; this largely respiratory increase of resistant A baumannii went unrecognized until January 1990.

Antimicrobial resistance in A baumannii is an important concern. Such resistance is not necessarily plasmid mediated. Tar geted surveillance for this and other agents of nosocomial infection should be used with caution, particularly in hospitals with many debilitated patients.

To evaluate epidemiologic factors that can be used to predict lack of measles immunity in healthcare workers.

During mandatory screening of employees for measles antibody, a questionnaire was used to collect demographic information.

Inpatient hospital, acute care clinics, and skilled nursing facility of a health maintenance organization.

Employees of all ages and occupations.

Measles immunity could not be predicted from history of measles disease and vaccination, gender, or birthplace. Of nonimmune employees, 63.7% were in the 20- to 29-year-old age group and 26.5% were in the 30-to 39-year-old age group.

Age is the most clinically Significant predictor of measles antibody, especially in persons born after 1950, who make up a large group susceptible to measles.

To identify an indicator of appropriate antibiotic use for bacteremia that is scientifically sound, that is noncontroversial, and that can be broadly applied as an index of the quality of care.

Retrospective review of consecutive cases of significant documented bacteremias.

Suburban tertiary-care hospital.

Two hundred ninety-one of 300 (97%) patients received appropriate antibiotics within 48 hours after the final antibiotic sensitivity report was placed on the hospital chart. Therapy was not appropriate in 6 patients with methicillin-resistant Staphylococcus aureus and in 3 patients with enterococcal bacteremia.

Following this study, we instituted a program to prospectively monitor antibiotic use in bacteremias. During the most recent 1-year period, the infectious disease fellow or pharmacist called the attending physician to change antibiotics in 84 of 731 (11.5%) patients with bacteremia. The program was well-accepted by attending physicians.

A scientifically sound, non-controversial standard of care was identified and used to evaluate the appropriateness of antibiotic use. When this standard was applied prospectively and incorporated into the hospital's routine operations, the quality of care was improved.