To study the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) over a prolonged period of time with the aid of a molecular typing method (ribotyping).

A 1,000-bed tertiary university medical center.

Defined epidemiological data were recorded for all patients culture-positive for MRSA between 1989 and 1992. Ribotyping of MRSA strains was performed using three restriction enzymes: EcoRv, HindHI, and KpnI.

From 1989 to 1992, MRSA was isolated from clinical specimens in 98 patients and from surveillance cultures in 27 patients. Among the 122 isolates available for typing, 26 different ribotypes were identified. In 20% of the cases, MRSA was community-acquired, and a third of these patients never had been hospitalized previously. Nine ribotypes were responsible for more than one case (2 to 64 patients); 17 appeared only once. Epidemiological data correlated with ribotyping results revealed 14 epidemiologic clusters involving six different ribotypes, whereas only three outbreaks were suspected initially. The median follow-up after the last isolation of a given ribotype was 14 months (range, 1 to 42) for clusters and 25 months (range, 1 to 46) for ribotypes that appeared only once. During clusters, only 16% of the cases occurred after the implementation of control measures in the ward (breakthrough cases).

The high diversity of MRSA strains observed over 4 years suggested that new strains were introduced continuously in our hospital. Furthermore, that 17 ribotypes were isolated only once, that breakthrough cases represented only 16% of the cases in clusters, and that the follow-up duration after the last isolation of a given ribotype was more than 14 months suggest that infection control measures were effective in limiting the nosocomial spread of MRSA over a prolonged period of time.

To characterize disposal-related sharps injuries.

A three-part study including (a) descriptive analysis of disposal-related injuries in a l-year period, (b) 4:l matched case-control study of nurses injured while using sharps disposal containers, and (c) survey to solicit opinions of users of containers.

An 1,181-bed teaching hospital in New York City.

For epidemiologic analyses, persons with self-reported injuries identified via New York State and Occupational Safety and Health Administration forms and control nurses without self-reported injuries. For survey, convenience sample of hospital nurses, laboratory workers, and maintenance workers.

Circumstances of injuries determined by study questionnaires. Employee opinions obtained by questionnaires and discussions during small group sessions.

Three hundred sixty-one persons reported sharps injuries, of whom 72 (20%) had disposal-related injuries. Persons with disposal-related injuries included four hospital visitors and one patient. Of 67 disposal-related injuries among employees, 25 (37%) directly involved use of a sharps disposal container. Significant risk factors for injury included container height greater than 4 ft above the floor, distance less than 5 ft from site of sharp object use to nearest container, and lack of attendance at universal precautions inservice classes. Survey groups involved 69 employees who identified a variety of preferred features for sharps disposal containers.

Disposal of sharp objects is an important cause of sharps injuries. Ergonomic factors, worker education, and appropriate container design should be considered in injury prevention strategies. Relevant guidelines and regulations are lacking and are needed.

To characterize risk factors for outbreak-associated influenza illness and death in a nursing home.

Outbreak investigation with predetermined and concurrently determined risk information.

A nursing home service in a multiward chronic care hospital, Honolulu, Oahu, 1989 to 1990.

Elderly nursing home patients receiving long-term care.

Influenza vaccination, amantadine administration, and infection control measures.

Neither routine infection control measures nor vaccination prevented illness, complications, or death in a nursing home outbreak of influenza A. The 55% case-fatality rate resulted from severe pneumonia. Influenza transmission may have been mediated by staff via either contaminated hands or fomites.

Data from this and other outbreaks suggest that recommendations for preventing nosocomial influenza in the nation’s 1.5 million nursing home residents should be reconsidered.

A biological indicator (BI), based on fluorescent detection of a spore-associated enzyme, has been developed. We evaluated the new BI against five conventional self-contained BIs in a 121°C gravity-displacement sterilizer and, packaged in towel packs and disposable steam test packs, in a 132°C vacuum-assisted sterilizer.

In the 121°C gravity-displacement sterilizer, rapid readout BIs and conventional BIs were tested together in an otherwise empty chamber. Exposure times were 5, 10, and 15 minutes. In the 132°C vacuum-assisted steam sterilizer, BIs were contained in towel packs or disposable steam test packs. Surgical packs were added to represent a full load. Exposure times were 0, 1, and 2 minutes.

In gravity-displacement 5-minute cycles, the rapid readout BIs yielded 100% positive results within 30 minutes. The conventional BIs ranged from 72% to 100% positive in 48 hours. At 10 minutes, the rapid readout BIs were 83% positive after 3 hours, whereas the conventional BIs ranged from 0% to 37% positive after 48 hours. All indicators were negative after 15-minute exposures. In vacuum-assisted cycles, all indicators were negative after 3 minutes. After 1-minute exposures, the rapid readout BIs were 40% to 60% positive, whereas the conventional BIs were 15% to 20% positive.

The rapid readout BIs are a more sensitive indicator of marginal steam sterilization cycles than conventional selfcontained BIs. They yield results within 3 hours, as compared to 24 to 48 hours for the conventional BIs.

To evaluate the impact of Occupational Safety and Health Administration (OSHA) regulations on the vaccination of healthcare workers (HCWs), to assess interpretation of these regulations, and to evaluate changes in hospital vaccination policies.

Between June 1, 1992, and August 15, 1992, a telephone survey was conducted among 150 hospitals selected randomly from participants in the American Hospital Association 1991 annual survey.

Of the 150 hospitals, 96 (64%) provided information on hepatitis B vaccination coverage of their employees. Of the 103,419 employees in these hospitals, 77,302 (75%) were eligible to receive the hepatitis B vaccine, and 38,850 (51%) of these were vaccinated completely (had received 3 doses of vaccine). Following issuance of the final regulations, 73% of hospitals reported greater employee acceptance of hepatitis B vaccine, and hospitals were more likely to offer hepatitis B vaccine to maintenance workers, security personnel, dietary staff, and clerical personnel. Seventy-five hospitals (59%) reported conducting postvaccination serologic testing on all hospital employees, 12 (8%) as a result of OSHA regulations. Twenty-three hospitals (16%) reported administering routine booster doses of hepatitis B vaccine at 3, 5, or 7 years.

The new OSHA standard resulted in a greater awareness of risk for HBV infection among HCWs and an increase in the number of HCWs receiving hepatitis B vaccine; however, vaccination coverage remained suboptimal. Postvaccination serologic testing of employees with negligible risk and the routine administration of vaccine booster doses may be diverting resources and preventing comprehensive coverage of high-risk employees.