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.

To compare patient outcomes when percutaneous feeding tubes were changed routinely each month or only when necessary (prn).

Prospective, randomized, nonblinded crossover study of 6 months of routine monthly changes compared with 6 months of prn changes.

416-bed long-term–care facility.

26 permanent residents with nutrition managed through percutaneous gastrostomy or jejunosto-my feeding tubes. The median age was 61.5 years; 8 (31%) also had tracheostomies, and 3 (12%) had indwelling urinary catheters.

The frequency of feeding tube changes was 40 per 1,000 patient-days during the 6 months of routine tube changes and 14 per 1,000 when tubes were changed prn (P<.001). There were no differences between the two study periods in frequency of stoma site infections, fever, episodes of emesis, and total antibiotic courses. The median duration in situ of feeding tubes with prn changes was 104 days. For both periods, feeding tubes were significantly more likely to fall out and require replacement within 24 hours of previous tube replacement.

There were no observed differences in clinical outcomes in long-term–care facility patients when feeding tubes were changed only as necessary as compared to routine monthly changes.

In May 1994, 43 persons in a nursing home were reported with gastroenteritis. An outbreak investigation was conducted to determine risk factors for gastroenteritis among residents and staff.

Data were analyzed using contingency tables; relative risks (RR) and statistical significance were determined with Fisher's Exact Test. The chi-squared statistic to perform a goodness of fit test for the binomial distribution was used to determine whether cases occurred randomly and independently of each other. Stools were tested for bacterial enteric pathogens, ova, and parasites and were examined by electron microscopy, Southern hybridization, and reverse transcription-polymerase chain reaction. Paired sera were collected to detect fourfold rises in antibody titer by enzyme immunoassay against Norwalk viruses.

Of 121 residents, 62 (51%) had gastroenteritis, as did 64 (47%) of the 136 staff. The index case was a nurse who became ill at work and continued to work, while symptomatic, for another 2 days. Only residents who had received medications from this nurse between May 17 and May 20 became ill on the first day of the outbreak (13 of 35 versus 0 of 5). Nurses and nurse aides were more likely than employees without direct resident contact to be cases (46 of 68 versus 18 of 58; RR, 2.18;P<.001). Bacterial stool cultures and parasite examinations were negative. Results of electron microscopy, polymerase chain reaction with Southern hybridization, and enzyme immunoassay indicated the causative agent was a small, round, structured virus similar to the Snow Mountain Agent.

To minimize outbreaks in nursing homes, we recommend that ill staff be excluded from work until symptoms resolve.

To assess risk factors associated with Clostridium difficile diarrhea in hospitalized adult patients, and to test the hypothesis that sucralfate ingestion is associated with nondetection of C difficile cytotoxin in stool specimens.

A retrospective case-control study of hospitalized adult patients who had stool specimens assayed for C difficile cytotoxin. For each patient who had positive C difficile cytotoxin, a patient who had negative C difficile cytotoxin was used as a control. The study period was January to December 1993.

A community teaching hospital affiliated with a medical school in northeastern Ohio.

There were 91 case patients and 91 control patients. Cephalosporin exposure was identified as a risk factor in patients with C difficile diarrhea. The number of patients who had sucralfate ingestion was comparable in both groups of patients.

Administration of cephalosporins was identified as a risk factor in patients with C difficile diar-rhea. We were not able to confirm a recent report of the association between ingestion of sucralfate and nondetection of C difficile cytotoxin in stool specimens. Our findings suggest that sucralfate ingestion is not associated with nondetection of C difficile cytotoxin in stool specimens. Assay ofC difficile cytotoxin in stool specimens remains a valid method of diagnosing C difficile diarrhea, even in patients who ingest sucralfate.

To determine the prevalence of gastrointestinal tract colonization with antibiotic-resistant enterococci at ward entry and to study the incidence and risk factors for nosocomial acquisition of colonization with resistant enterococci.

A prospective cohort study conducted between February 1 and March 15, 1993.

Rectal cultures were obtained within 24 hours of admission or transfer onto the study wards and repeated at weekly intervals and at the time of discharge. Patients harboring antibiotic-resistant enterococci at the time of admission or after admission were compared to patients who were not colonized with these organisms. Clinical and epidemiologic risk factors for colonization were abstracted prospectively by daily chart review. Following a univariate analysis of risk factors associated with colonization, a multivariate statistical analysis using three separate models was done.

A 1,125-bed, tertiary-care teaching hospital in North Carolina.

A total of 350 patients admitted to two general medical wards and the medical intensive care unit during the study period.

Antibiotic-resistant enterococci were isolated from 52 patients: 19 were colonized at admission to the study, and 33 later acquired resistant strains. At the time of admission, 5.4% of the patients were colonized with ampicillin-resistant enterococci (ARE), including 1.1% that were colonized with vancomycin-resistant enterococci. Prior hospitalization was associated with colonization with ARE at admission (P=.01). Independent risk factors for nosocomial acquisition of ARE included treatment with more than three antibiotics, empiric use of antibiotics, use of third-generation cephalosporins, and the use of enteral tube feedings. Antibiotics used prophylactically were not associated with resistant enterococcal colonization.

Our data help to elucidate the epidemiology of gastrointestinal tract colonization with resistant enterococci. We hypothesize that surveillance and control programs will be more likely to succeed if targeted at patients receiving more than three antibiotics, empiric antibiotics, and enteral tube feedings.