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 investigate suspected pseudo-outbreaks of Mycobacterium tuberculosis (MTB) during August 1994 and July 1995 among patients who did not have clinical findings consistent with tuberculosis.

Retrospective and prospective surveys of all clinical and laboratory data using standard epidemiological tools and DNA fingerprinting.

A university-affiliated community hospital.

Those with positive MTB cultures during periods when we noted that the number of MTB positive cultures greatly outnumbered the usual monthly average (retrospective analysis, 1994) and patients with positive MTB cultures without clinical findings consistent with tuberculosis (prospective survey, 1995).

Epidemiological and molecular studies revealed specimen cross-contamination in the laboratory due to a faulty exhaust hood. Improvement in laboratory ventilation and change of the implicated hood prevented further specimen contamination.

The identification of positive MTB cultures from patients without clinical evidence of tuberculosis should be a signal to suspect laboratory contamination and implement control measures. These should include a thorough epidemiological investigation, DNA fingerprint analysis, and an environmental inspection.

To assess the prevalence of nosocomial infections at a rural government hospital from 1992 to 1995.

Retrospective review of data from 1992 to 1995 regarding rates of nosocomial infections, cost to government, and infection control practices.

653-bed rural hospital providing primary and tertiary care.

Patients admitted to the hospital between 1992 and 1995 who were found with hospital-acquired infections during their stay.

None.

Over the 4-year period, 7,158 nosocomial infections were identified from 72,532 patients (10.0/100 admissions). High nosocomial infection rates were found on the intensive-care unit (67/100 admissions), urology (30/100 admissions), neurosurgery (29.5/100 admissions), and newborn nursery (28.4/100 admissions). Urinary tract infections (4.1/100 admissions) accounted for most nosocomial infections (42%), followed by postoperative wound infections (26.8%) with a rate of 2.6/100 admissions. Nosocomial pneumonias and bloodstream infections also were common with 13.2% and 8.0%, respectively. The highest rates occurred on the intensive-care unit for both pneumonia (26.4/100 admissions) and bloodstream infection (7.0/100 admissions). The cost to the government for nosocomial infections was estimated at US $697,000 annually (US $1=$6 Trinidad and Tobago). Poor infection control practices, inadequate handwashing facilities, lack of supplies, and nonexistent garbage cans on most wards were quite evident.

Strict adherence to proper infection control practices, such as handwashing techniques, and improvement of facilities are crucial steps in preventing cross-infections in the hospital environment. Implementing these measures may substantially reduce the massive drain on the hospital budget in treating nosocomial infections. The saved revenue could go toward improvement of ward facilities and reduction of over-crowding, thus further reducing cross-infection.