To evaluate measures intended to reduce Legionella infections in patients undergoing bone marrow transplantation (BMT).

Ongoing clinical and microbiological surveillance for Legionella colonization or infection was undertaken. All neutropenic patients with pulmonary infiltrates and fever unresponsive to broad-spectrum antibiotics were tested for Legionella organisms.

A 505-bed medical-surgical hospital with a designated BMT unit.

Two hundred twenty-five patients underwent BMT; 201 were treated on a new BMT unit. The incidence of Legionella infections was compared to that seen in an estimated 150 neutropenic patients treated on other units.

A combined approach to decontamination of a hospital water supply was assessed. This included heating, particulate filtration, ultraviolet sterilization, and monthly pulse hyperchlorination of water supplied to the BMT unit. The incidence of Legionella infections was assessed on the BMT unit and compared with the frequency elsewhere in the hospital.

There were only three cases of Legionella pneumonia among 201 patients undergoing transplantation on a new BMT unit. In contrast, 33 cases of Legionella infections were detected from approximately 150 patients treated on general medical floors.

A multifaceted approach to decontamination of a hospital water system led to a marked reduction in Legionella infections.

To describe the spectrum of clinical infection caused bymethicillin-resistant Staphylococcus aureus (MRSA) in healthcare workers.

Case series.

Two Veterans Affairs hospitals in which methicillin-resistant S aureus (MRSA) is endemic.

Five employees presenting to employee health or infectious disease clinic.

All employees had had direct exposure to patients colonized with MRSA. Employee infections included cellulitis, impetigo, folliculitis, paronychia, and conjunctivitis. MRSA was isolated from all clinically infected sites and from the anterior nares of two employees. Three employees received a variety of ineffective oral antimicrobials before MRSA was recognized as the causative agent. All infections responded to appropriate therapy.

Employees of hospitals with endemic MRSA may acquire MRSA infection. Presentation in our employees was that of relatively uncomplicated soft tissue infection, but several employees received inappropriate therapy before bacteriologic diagnosis. We recommend that culture and susceptibility testing be obtained prior to institution of therapy when hospital employees present with soft tissue infection.

To study risk factors for the highly variable local colonization rates with unrelated Enterobacter species strains previously found in 22 Swedish neonatal units (0% to 32.4% of the infants).

The fecal Enterobacter species carriage rates among 953 infants in the 22 special-care neonatal units were correlated with variables related to the ward (size, crowding, staffing, work load, antibiotic usage, level of care, hygienic precautions), and the hospital (temperature of water supplied, geographical location).

The average Enterobacter species carriage rate was highest at seven days of age (17% of the infants) and then declined to 3%. Only location of the hospital in an area with warmer climate according to horticultural zone showed an association with Enterobacter species carriage in multivariate analysis (P= 0.005).

Although Enterobacter species mainly cause nosocomially acquired infections, the occurrence of the organism in special-care neonatal units seemed to be determined more by extrahospital than by intrahospital factors.

The investigation and control of an outbreak of nosocomial Pseudomonas cepacia respiratory tract colonization and infection.

Epidemiologic investigation based on infection control surveillance data, including definition and characterization of case patients, environmental cultures based on epidemiologic information, and institution of control measures based on study results.

A 1,171 -bed, university-affiliated tertiary care hospital.

Between January 1, 1988, and June 30, 1989, 127 patients were culture-positive for P cepacia, 117 (92%) of whom were culture-positive from sputum and were treated in the intensive care unit. Review of respiratory care procedures revealed that when mechanical ventilators were serviced between patients, the electronic temperature probes used with servo-controlled humidifiers were wiped with the same odor-counteractant cleaning solution used on ventilator cabinets, P cepacia was isolated from nine of 12 in-use temperature probe tips, three of which were from patients with negative sputum cultures for P cepacia, one of whom subsequently developed culture positivity for P cepacia.

P cepacia also was isolated from the diluted odor-counteractant solution. Following the institution of a disinfection procedure for temperature probe tips, the incidence of P cepacia sputum culture positivity in ICU patients fell significantly compared to the outbreak period (138 of 5,225 discharges versus 52 of 3,678 discharges, P<0.01).

This investigation identified contamination of reusable electronic temperature probes as a source of nosocomial respiratory infection due to P cepacia and emphasizes the need to carefully evaluate disinfection practices for reusable patient care equipment.

To describe an outbreak of Candida tropicalis fungemia in a neonatal intensive care unit (NICU), to evaluate the risk factors associated with this infection and the possible mode of nosocomial transmission.

Descriptive and case-control study

Surveillance cultures were taken from hospitalized patients, personnel, and inanimate objects in the NICU. Six patients with C tropicalis fungemia (cases) were compared with C tropicalis culture-negative patients matched for duration of exposure to the NICU (controls).

During a five-month period, C tropicalis was isolated from 29 blood cultures of six premature infants. The same organism also was isolated from fingernail samples taken from the ward housekeeper, who had a mild onychomycosis, and an asymptomatic nurse. Other potential reservoirs of C tropicalis were not identified among all the other infants or in the hospital environment. The six patients with C tropicalis fungemia were more likely to have received a larger number of antibiotics (4.0 versus 1.8, R<0.001) and to have been subjected to a longer duration of total parenteral nutrition (TPN) therapy (8.5 versus 2.67 days, P= 0.004) than the controls.

The risk of fungemia in this outbreak can be attributed to a larger number of antibiotics and a longer period of TPN administered to the patients. Analysis of events suggests that the outbreak may have been the result of cross-infection between staff and patients.