Control of a prolonged outbreak of extended-spectrum beta-lactamase-producing enterobacteriaceae in a university hospital.

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLPE) were isolated from clinical specimens from 130 to 140 patients/year in 1989-1991 in our hospital. In February 1992, a control program was initiated: screening tests in 3 intensive care units (ICUs) and contact-isolation precautions in all units. The septic surgical unit served as an isolation ward for surgical patients from whom ESBLPE was isolated. In 1992, the incidence of ESBLPE acquisition failed to decrease, and most acquisitions occurred in 3 ICUs. Critical evaluation of implementation of isolation procedures in these ICUs prompted corrective measures for barrier precautions. The incidence of acquired cases subsequently decreased, and a second evaluation determined that these measures had been correctly applied. The incidence of acquired cases in the septic surgical unit was lower than those in the other units. Decreases were also found in the incidence of acquisition of other hand-transmitted multidrug-resistant organisms. Barrier precautions, screening tests for ICU patients, and grouping of cohorts after ICU discharge are effective in controlling the spread of multidrug-resistant microorganisms by cross-contamination. The outbreak was effectively controlled without restricting antimicrobial use.

A nosocomial outbreak of multidrug-resistant Mycobacterium bovis among HIV-infected patients. A case-control study.

OBJECTIVE: To identify risk factors in a nosocomial outbreak of multidrug-resistant Mycobacterium bovis (MDRMB) tuberculosis (TB) among HIV-infected patients. DESIGN: We evaluated the study period (from the first to the last MDRMB smear-positive patients hospitalized in the unit) using a case-control study with three control groups. Since MDRMB is extremely rare, we assumed that a single strain was responsible for all six cases. SETTING: A 19-bed infectious diseases unit in Paris, France. PATIENTS: The index case was an AIDS patient who was hospitalized in September 1989 because of MDRMB TB. The cases were five HIV-infected patients who developed MDRMB TB between January 1990 and October 1991. Controls were randomly selected from HIV-infected patients in our unit during the study period (case-control study 1, 15 patients), during the contact period (at least one MDRMB smear-positive patient hospitalized in the unit; case-control study 2,20 patients), and patients matched according to the length of contact (case-control study 3, 24 patients). INTERVENTIONS: After detecting the nosocomial outbreak, we took respiratory isolation precautions for all patients suspected of having active TB. MAIN OUTCOME MEASURES: Risk factors for MDRMB nosocomial transmission, and the occurrence of new cases of MDRMB infection in HIV-infected patients and health-care workers after the introduction of isolation precautions. RESULTS: The most important predictor of nosocomial transmission of MDRMB to HIV-infected patients was the (mean +/- s.d.) length of contact in days [cases, 22 +/- 15.8; study 1 controls, 11.2 +/- 18.9 (P = 0.07); study 2 controls, 14.6 +/- 8.5 (P = 0.043)]. Only one case of MDRMB TB resulted from exposure to MDRMB-smear-positive patient after the introduction of respiratory isolation measures. The incubation period in the single health-care worker who developed MDRMB TB was longer than in the cases. CONCLUSION: In a nosocomial outbreak of MDRMB TB, the contact time was the main risk factor of transmission to HIV-infected patients. Respiratory isolation measures appear to be effective.

[Occupational risk of exposure to blood in nurses. Results of a one-year monitoring of the risk for nurses in 17 hospitals]. / Exposition accidentelle au sang du personnel soignant. Résultats d'un an de surveillance du risque pour les infirmières dans 17 hôpitaux.

To evaluate the incidence of risk factors for exposure of health care providers to patients' blood, a prospective multicenter study was carried out in 1990 in 17 hospitals in continental France. 521 nurses from 20 departments of medicine and 9 intensive care nurses participated in the study. Trained investigators documented exposures to blood using a standardized questionnaire and carried out monthly 24 hours cross-sectional surveys to determine the number of high risk procedures performed on a given day. One hundred and eighty-three exposures to blood were documented, for an incidence of 0.35/nurse/year. Needle-stick injuries were the most common events (75%). Exposure to blood occurred during a sampling procedure in 48% of cases, an infusion-related procedure in 20% of cases, and an injection in 17% of cases. Comparisons of rates of procedures associated with needle-stick injuries and of procedures performed during a typical day demonstrated differences in the magnitude of the risk associated with each procedure: infusion-related procedures carried the greatest risk, followed by venous blood sampling procedures. Sixty-four percent of exposures to blood occurred after completion of the procedure. Forty-nine percent of documented exposures to blood would probably not have occurred if universal infection control recommendations (CDC, DGS) had been implemented. Twenty-seven percent of exposures to blood involved HIV-positive patients, who accounted for only 7% of patients managed in the participating centers during the study period.(ABSTRACT TRUNCATED AT 250 WORDS)