To determine the effect of different methods of training on the ability of hospital workers to wear respirators and pass a qualitative fit test, and to compare the direct cost of the training.

179 hospital employees were recruited for study and were stratified into three groups based on the type of training they received in the use of respirators. Employees in Group A received one-on-one training by the hospital's industrial hygienist and were fit tested as part of this training. Employees in Group B received classroom instruction and demonstration by infection control nurses in the proper use of respirators, but were not fit tested as part of training. Employees in Group C received no formal training. Each participant in our study underwent a subsequent qualitative fit test using irritant smoke to check for the employee's ability to adjust correctly the fit and seal of the respirator. The direct cost of each method of training was determined by accounting for the cost of trainers and the cost of employee-hours lost during training.

775-bed Veterans' Affairs hospital.

94% of Group A participants (49 of 52) passed the qualitative fit test, compared to 91% of Group B participants (58 of 64) and 79% of Group C participants (50 of 63; P=.036, 2 × 3 chi-square). Group A had a significantly higher pass rate than Group C (P=.043), but Group B did not differ significantly from Group A or Group C. Location or professional status did not affect pass rate, but prior experience wearing respirators did. When the study groups were compared after stratifying for prior experience, we found no difference in pass rates, except when Groups A and B (those with any training) were combined and compared with Group C (107 of 116 versus 50 of 63, P=.05, Mantel-Haenszel chi-square).

We estimate that the method of training involving individual instruction followed by fit testing took 20 minutes per employee to complete, compared to 10 minutes per six employee class for the method of classroom demonstration. The difference in direct cost between the two methods, applied to the training of 1,200 employees at our hospital, would be approximately $19,000 per year.

Our study indicates that training in the proper use of respirators is important, but the method of training may not be, as the two methods we evaluated were nearly equivalent in their pass rates on fit testing (94% versus 91%). Fit testing as part of training may have enhanced the performance of our participants marginally, but was more time consuming and accounted for most of the excess cost.

To study compliance with preventive strategies at a university hospital during an outbreak of nosocomial influenza A during the winter of 1988, and the rates of vaccination of healthcare workers and of nosocomial influenza following changes in vaccine practices after the outbreak.

Retrospective review of employee health, hospital epidemiology, hospital computing, and clinical microbiology records.

A university hospital.

Unvaccinated personnel with exposure within the previous 72 hours to an unisolated case of influenza were offered influenza vaccine and 14 days of amantadine hydrochloride prophylaxis. Personnel with exposure more than 72 hours before evaluation were offered vaccine. A mobile cart was introduced for vaccinating personnel after the 1988 outbreak.

An outbreak of influenza with 10 nosocomial cases occurred in 1988. Only 4% of exposed employees had been vaccinated previously and 23% of exposed, unvaccinated employees agreed to take vaccine, amantadine, or both. A mobile-cart vaccination program was instituted, and annual vaccination rates steadily increased from 26.3% in 1989 to 1990 to 38% in 1993 to 1994 (P<.0001). The relative frequency of documented cases of influenza in employees with symptoms of influenza decreased significantly during this period (P=.025), but nosocomial influenza rates among patients did not change significantly.

A mobile-cart influenza vaccination program was associated with a significant increase in compliance among healthcare workers, but a majority still remained unvaccinated. The rate of nosocomial influenza among patients was not reduced by the modest increase in the vaccination rate, but influenza rates remained acceptably low, perhaps due to respiratory isolation of patients and furlough of employees with influenza.

To evaluate endemic colonization with Staphylococcus aureus resistant to methicillin, ciprofloxacin, or both among patients of a private skilled nursing facility, with regard to colonization rate and site, and relation to infection and prior antibiotic use.

Prospective quarterly culture surveillance of nares and rectal specimens over 20 months' observation.

The mean prevalence was 3.8% in new admissions and 5.4% for in-house patients; cumulatively, 7.5% of the patients were colonized during the study period. The colonization rate remained stable during the study period. Screening of rectal, as well as nares, specimens detected substantially more colonized patients than would have been detected by nasal cultures alone. Five to seven percent of the colonized patients developed later infection with methicillin-ciprofloxacin-resistant S aureus. Colonized patients did not differ significantly from the noncolonized group in prior use of quinolones, but the colonized group was exposed significantly more frequently to other antibiotics than the noncolonized group. Eighty-three percent of methicillin-resistant S aureus (MRSA) isolated from infections and 89% from colonization were also ciprofloxacin resistant.

Although all infecting and most colonizing isolates of MRSA were resistant to quinolones, the overall rate of colonization remained low and stable despite the continued use of quinolones. The findings suggest that good infection control practice has prevented broader spread of such strains in this facility.

Evaluation of the quantitative antibiogram as an epidemiological tool for the prospective typing of methicillin-resistant Staphylococcus aureus (MRSA), and comparison with ribotyping.

The method is based on the multivariate analysis of inhibition zone diameters of antibiotics in disk diffusion tests. Five antibiotics were used (erythromycin, clindamycin, cotrimoxazole, gentamicin, and ciprofloxacin). Ribotyping was performed using seven restriction enzymes (EcoRV, HindIII, KpnI, PstI, EcoRI, SfuI, and BamHI).

1,000-bed tertiary university medical center.

During a 1-year period, 31 patients were found to be infected or colonized with MRSA. Cluster analysis of antibiogram data showed nine distinct antibiotypes. Four antibiotypes were isolated from multiple patients (2, 4, 7, and 13, respectively). Five additional antibiotypes were isolated from the remaining five patients. When analyzed with respect to the epidemiological data, the method was found to be equivalent to ribotyping.

Among 206 staff members who were screened, six were carriers of MRSA. Both typing methods identified concordant of MRSA types in staff members and in the patients under their care.

The quantitative antibiogram was found to be equivalent to ribotyping as an epidemiological tool for typing of MRSA in our setting. Thus, this simple, rapid, and readily available method appears to be suitable for the prospective surveillance and control of MRSA for hospitals that do not have molecular typing facilities and in which MRSA isolates are not uniformly resistant or susceptible to the antibiotics tested.

To determine persistence of coagulase-negative staphylococci (CNS) on a hematology-oncology ward and to determine the value of phenotypic and genotypic procedures for establishing clonality among CNS isolates.

Strains of CNS isolated from bacteremic patients (n=139) were typed by biochemical reactivity, antibiotic susceptibility, DNA macrorestriction analysis by pulsed-field gel electrophoresis (PFGE), and arbitrary primed polymerase chain reaction (AP PCR). Coagulase-negative staphylococci were subgrouped in a random collection (n=20) used for the evaluation of the typing procedures and a collection of 119 CNS isolates from hematologic patients displaying multiple bacteremic episodes.

Analysis of the reference collection demonstrated the usefulness of the DNA typing procedures, indicating that AP PCR and PFGE can be used for epidemiologic typing of CNS in a concordant fashion. Certain strains appeared to be permanent colonizers of the hematology ward or ward-related personnel. In individual patients, persistent colonization by a single type was demonstrated. However, a number of patients also experienced bacteremic episodes caused by CNS belonging to different types.

We conclude that monitoring of CNS infections on a hematology ward by various genotypic techniques provides insight into nosocomial epidemiology and elucidates the complexity of the infections taking place. DNA typing is preferred over phenotypic procedures and can identify persistent CNS strains in a given location.

Evaluate a plasmid typing technique for a diverse group of staphylococci.

In vitro testing on known isolates.

University hospital.

The plasmid content of 195 isolates representing 26 staphylococcal species was analyzed by agarose gel electrophoresis following lysostaphin-alkaline-SDS lysis, with and without acetone treatment.

Isolates yielded plasmid profiles with 0 to 7 extra-chromosomal bands (median, 1; 1.5); 171 (88%) had a profile with at least 1 band. Species with more than one isolate available for testing showed considerable diversity of plasmid profiles, except for Staphylococcus haemolyticus.

The ease of the procedure and the diversity of plasmid profiles within each species examined suggests that plasmid profiling is an accessible and useful epidemiologic tool applicable to most staphylococcal species by epidemiologic units or clinical laboratories.