To describe management and outcome of tuberculosis (TB) and current practices for isolation in two urban hospitals in the Midwest.

Retrospective cohort study.

Barnes Hospital and Jewish Hospital, tertiary-care and community hospitals affiliated with Washington University School of Medicine in St Louis, Missouri.

All adult patients with a positive culture for Mycobacterium tuberculosis from 1988 to 1994.

We identified 122 cases at Barnes and Jewish Hospitals (36.5/100,000 hospital discharges), median age was 59.0 years, 61.5% were non-Caucasian, and 54.9% resided within the city limits. Underlying risk conditions were common: substance abuse (25%), recent TB contact (24%), and foreign birth (13%). Coexistent human immunodeficiency virus infection (8%) was uncommon. Of skin-tested cases, 22% were anergic; of the rest, 22% tested negative. Almost 20% of cases had prior positive skin tests, and thus were preventable, but had not received adequate prophylaxis. Of hospitalized patients with pulmonary TB, 70% received respiratory isolation. Antibiotic resistance was recognized in 16%; only 19% of cases initially received four-drug therapy. TB-related death occurred in 16%.

In this area, TB cases primarily involve traditional risk groups without HIV coinfection. Current infection control practices, diagnostic strategies, and initial treatment regimens are suboptimal. Education about local disease epidemiology is needed to prevent nosocomial TB transmission.

To evaluate a clinical guideline and an automated computer protocol for detection and respiratory isolation of tuberculosis (TB) patients.

An automated computer protocol was tested on a retrospective cohort of adult culture-positive TB patients admitted from 1992 to 1993 to Columbia-Presbyterian Medical Center and evaluated prospectively from July 1995 until July 1996.

A large teaching hospital in New York City.

171 adult patients admitted from 1992 to 1993 and 43 patients admitted between July 1995 and July 1996.

The 1990 Centers for Disease Control and Prevention guidelines for preventing transmission of TB were adapted to formulate clinical guidelines to ensure early isolation of TB patients at Columbia-Presbyterian Medical Center.

Implementation of a clinical respiratory isolation protocol resulted in a significant improvement in TB patient isolation rates, from 45 (51%) of 88 in 1992 to 62 (75%) of 83 in 1993 (P<.001). In testing automated protocols, the theoretical improvement would have identified an additional 27 patients not isolated by clinicians, making the overall isolation rate 134 (78%) of 171.

For the prospective evaluation, 30 (70%) of 43 TB patients were isolated by clinicians adhering to the clinical protocol. Four additional patients were identified by the automated TB protocol, making the combined isolation rate 34 (79%) of 43.

A clinical policy to isolate TB patients and suspected human immunodeficiency virus-infected patients with cough, fever, or radiographic abnormalities improved isolation of culture-documented TB patients from 1992 to 1993. Automated computer protocols were successful in identifying additional potentially infectious patients that clinicians failed to place on respiratory isolation. Clinical and automated protocols combined resulted in better isolation rates than a clinical protocol alone.

To identify the etiologic agent and risk factors associated with a hospital ward outbreak of gastroenteritis.

A regional referral hospital in upstate South Carolina.

We reviewed patient charts, surveyed staff, and tested stool from acutely ill persons. A case was defined as diarrhea and vomiting in a staff member or patient from January 5 to 13, 1996.

The initial case occurred on January 5 in a staff nurse who subsequently was hospitalized on the ward and visited by many staff colleagues. The staff were at a significantly greater risk for gastroenteritis than were patients (28/89 [31%] vs 10/91 [11%]; relative risk [RR], 2.9; 95% confidence interval [CI95], 1.5-5.5). All 10 case-patients had been exposed to case-nurses (assigned nurses who were primary caretakers), and eight had documented exposure to case-nurses 1 to 2 days before their illness. Patients exposed to case-nurses had a significantly increased risk of illness (8/57 [14%] vs 0/32; RR, >4.5; CI95, undefined). Neither staff nor patients had significantly increased risk from food, water, ice, or exposure to case-patients. Electron microscopy identified small round-structured viruses (SRSVs) in nine of nine stool samples.

This nosocomial outbreak of gastroenteritis was likely caused by SRSVs introduced by a staff member and spread via person-to-person transmission from and among staff. The potential for spread of SRSV-associated gastroenteritis from and among staff should be considered in developing strategies to prevent similar outbreaks in hospital settings

To determine the frequency of, and risk factors for, infections associated with intra-arterial catheters used for cancer chemotherapy.

Between September 1992 and September 1995, we conducted a surveillance study of all 807 intra-arterial catheters placed for chemotherapy at our center. The insertion site was disinfected with povidone iodine and alcohol, and the arterial catheter was placed using maximal sterile barrier precautions. Upon removal, all intravascular segments were submitted for semiquantitative culture.

No episodes of catheter-related bloodstream infection (95% confidence interval [CI95], 0%-1.6%) were observed. However, the risk of colonization (>15 colony-forming units) of arterial catheters was 15% (CI95, 12%-17%). Retrospective risk-factor analysis conducted on 224 intra-arterial catheters placed for chemotherapy in 1993 showed that colonization was associated significantly with duration of catheterization (median of 1 day for culture-negative catheters vs median of 4 days for culture-positive catheters, P<.001). Age, gender, prior radiotherapy, underlying cancer, neutropenia, and hypoalbuminemia were not associated with catheter colonization.

Intra-arterial catheters for cancer chemotherapy placed under maximal sterile barrier precautions for a short period of time are associated with a very low risk of bloodstream infection.

To investigate a cluster of cases of legionnaires' disease among patients at a hospital.

A university hospital that is a regional transplant center.

Retrospective review of microbiology and serology data from the hospital laboratories and prospective surveillance via the radiology department; a case-control study and environmental sampling within the hospital and from nearby cooling towers.

Diagnosis of seven cases of legionnaires' disease in the first 9 months of 1996 led to recognition of a nosocomial outbreak that may have begun as early as 1979. Review of charts from 1987 through September 1996 identified 25 culture-confirmed cases of nosocomial or possibly nosocomial legionnaires' disease, including 18 in bone marrow and heart transplant patients. Twelve patients (48%) died. During the first 9 months of 1996, the attack rate was 6% among cardiac and bone marrow transplant patients. For cases that occurred before 1996, intubation was associated with increased risk for disease. High-dose corticosteroid medication was strongly associated with the risk for disease, but other immunosuppressive therapy or cancer chemotherapy was not. Several species and serogroups of Legionella were isolated from numerous sites in the hospital's potable water system. Six of seven available clinical isolates were identical and were indistinguishable from environmental isolates by pulsed-field gel electrophoresis. Initial infection control measures failed to interrupt nosocomial acquisition of infection. After extensive modifications to the water system, closely monitored repeated hyperchlorinations, and reduction of patient exposures to aerosols, transmission was interrupted. No cases have been identified since September 1996.

Legionella can colonize hospital potable water systems for long periods of time, resulting in an ongoing risk for patients, especially those who are immunocompromised. In this hospital, nosocomial transmission possibly occurred for more than 17 years and was interrupted in 1996, after a sudden increase in incidence led to its recognition. Hospitals specializing in the care of immunocompromised patients (eg, transplant centers) should prioritize surveillance for cases of legionnaires' disease. Aggressive control measures can interrupt transmission of this disease successfully.