To determine the epidemiology of Staphylococcus aureus infections in hemodialysis patients.

S aureus isolates from surveillance cultures and from sites of infection were evaluated by both bacteriophage typing and restriction endonuclease digestion of plasmid DNA.

A hemodialysis unit in Brugge, Belgium.

S aureus isolates from 11 chronic hemodialysis patients who had participated in the placebo arm of a previously reported placebo-mupirocin comparative study.

Of 75 S aureus isolates evaluated, 63 were from cultures of nares and 12 from infections (three arteriovenous fistula infections, four wound infections, and five bacteremias). All isolates were typed by bacteriophages and 56 (75%) had plasmids. Three patients developed 12 infections. Eleven infections were caused by isolates previously identified in surveillance cultures. Only one infection was caused by a strain not identified previously in surveillance cultures.

These results support the hypothesis that S aureus isolates causing infections in hemodialysis patients are of endogenous origin.

A cluster of bacterial contamination of platelets occurred at a university hospital in a one-month period. This unusual clustering allowed us to examine the likely mechanism of contamination and clinical sequelae.

We reviewed medical records of patients receiving random donor platelet transfusions to determine numbers of platelets transfused, reactions reported, and episodes of bacterial contamination. We also reviewed procedures at the collecting blood agencies and the hospital blood bank.

Four patients received bacterially contaminated platelets during June and July 1991. The rates of reported platelet transfusion reactions increased significantly (P<0.001) from September 1989 through July 1991 (study period); in addition, the rate of contamination of platelets during June and July 1991 was 23-fold higher than during the previous 21 months (P< 0.00 1). Surveillance methodology changed dramatically during the study period, contributing to the recognition of the current cluster. Pathogens isolated from the contaminated platelet pools were Bacillus cereus, Staphylococcus epidermidis, or Pseudomonas aeruginosa in titers ranging from 106 to 108 colony forming units/ml. Four constituent individual platelet units identified as the probable cause of the outbreak (including one postepidemic episode) were significantly older (mean age, 4.8 days) than 106 randomly selected individual platelet units (mean age, 3.7 days; P = 0.04). Platelet pools were transfused an average of 2.5 hours after pooling. Review of blood collection and platelet preparation practices did not identify breaks in procedure or technique that could have caused contamination.

Increased awareness of platelet transfusion reactions by clinical staff and routine culturing of all platelets associated with transfusion reactions will identify contaminated platelets. Identification of contaminated platelets is necessary to treat affected patients appropriately and to determine the prevalence of and risk factors for contaminated platelets.

To better define the role of multiple risk factors for cytotoxic Clostridium difficile-associated diarrhea.

Case-control study.

A Veterans Affairs Medical Center.

Thirty-three case patients with C difficile -associated diarrhea. Two control groups were used: one group consisted of 32 patients from the same ward as the case patients, and one group consisted of 34 patients with nosocomial diarrhea and negative C difficile toxin assays.

None.

Multivariate analyses revealed that exposure to second- or third-generation cepha-losporins was the most important independent risk factor, even after controlling for other antimicrobial use (odds ratio [OR]=8.3, 95% confidence interval [CI95] = 1.4 to 48.9 compared to ward controls; OR= 9.6, CI95 = 2.1 to 44.1 compared with diarrhea controls). Persons exposed to two or more antimicrobials simultaneously were at substantially elevated risk (OR= 18.7, CI95 = 4.1 to 85.8 compared with ward controls; OR=21.5, CI95=3.2 to 141.9 compared with diarrhea controls).

Physicians should consider carefully the appropriateness of second- and third-generation cephalosporin use and combination antimicrobial therapy, especially during nosocomial C difficile -associated diarrhea outbreaks.

To determine the prevalence of tuberculous infection among a sample of physicians at Barnes Hospital and to determine the frequency of tuberculin skin testing and the adequacy of follow-up for physicians with positive tuberculin skin tests.

Convenience sample.

1,000-bed, university-affiliated tertiary care hospital.

Physicians attending departmental conferences were screened for tuberculosis. Prior history of tuberculosis, antituberculous therapy, BCG vaccination, and previous tuberculin skin test results were obtained with a standardized questionnaire. Tuberculin skin tests were performed on those who were previously skintest negative.

Tuberculosis infection, prophylactic therapy.

Eighty-six (24.5%) of 351 physicians in the study were skin test positive by history or currently performed skin test. Of 61 who reported a previously reactive skin test, 40 (66%) had been eligible for isoniazid prophylaxis, but only 15 (37.5%) of 40 had completed at least six months of therapy. Of 290 physicians reporting a previously negative skin test, 25 conversions (8.6%) were identified. Previously undiagnosed, asymptomatic pulmonary tuberculosis was identified in one physician.

Infection with Mycobacterium tuberculosis is common among physicians. Physicians were screened irregularly for tuberculosis, and the use of prophylactic therapy was inconsistent. Aggressive tuberculosis screening programs for healthcare workers should be instituted.

To ascertain the etiology and outcome of episodes of bacteremia and fungemia over a three-year period (1990-1992) in patients with hematological malignancies.

Retrospective study.

Hematology service of a 1,500-bed Spanish university hospital.

Of a total of 178 episodes of significant bacteremia or fungemia in 101 patients, 53% affected patients with acute leukemia. Grampositive microorganisms were found to be the cause in 70% of the monomicrobial episodes. The most frequently isolated microorganism was coag-ulase-negative Staphylococcus (35%), followed by Staphylococcus aureus (11%). Most bloodstream infections occurred during an episode of neutropenia (59%). A total of 34 patients died during hospitalization; in 14, infection was the cause of death.

A marked increase in the incidence of bacteremias caused by grampositive microorganisms has been observed in our hospital over the last 10 years, especially in patients with hematological malignancies. The mortality due to bacteremia is similar to that found by other authors in series of bacteremia in hematological patients, and we have not found significant differences in the mortality due to bacteremia between neutropenic and non-neutropenic patients.