To describe a nosocomial outbreak caused by multiresistant Acinetobacter baumannii.

Descriptive and case-control study. Antibiotic susceptibilities and pulsed-field gel electrophoresis (PFGE) of genomic DNA digested with Sfil and also with Apal were used as markers of strain identity.

A large medical school-affiliated hospital in the city of Houston, Texas.

During a 10-week period, A baumannii was isolated from 25 patients admitted to the intensive care unit (ICU). The attack rate was 14.3 per 100 ICU admissions. Case patients were intubated more frequently and for longer periods, and had longer ICU and hospital stays (P<0.05 for each of these characteristics). Multivariate logistic regression analysis identified the length of ICU stay and the use of third-generation cephalosporins as associated with the acquisition of A baumannii. Patients infected with A baumannii had a higher mortality rate than colonized patients and control patients [P<0.0l). Sixteen isolates recovered from these 25 patients were susceptible only to imipenem/ cilastatin, and PFGE confirmed that a single clone was the cause of this outbreak. Nine isolates of A baumannii from patients infected or colonized in two other hospitals in Houston during the same period, differed from the outbreak isolates by their susceptibility to ciprofloxacin. However, PFGE results were identical, indicating unsuspected genetic relatedness among isolates from three different hospitals.

A baumannii is an important nosocomial opportunistic pathogen and can adversely affect the outcome of ICU patients who acquire this organism. This outbreak was caused by a single clone that was isolated concurrently from three hospitals.

To describe the frequency and patterns of infection caused by methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S aureus (MRSA) infections in a single nursing home population and to determine the effect of MRSA's entry into the facility on subsequent experience with both MSSA and MRSA infections.

Observational and descriptive. Surveillance data on nursing home-acquired infections were reviewed to identify all patients with MSSA and MRSA infections occurring during the 5-year period from 1987 to 1991. The medical records of these patients were reviewed retrospectively to collect additional information about the patients and their infections.

A 120-bed Veterans' Affairs nursing home care unit (NHCU) whose residents predominantly were elderly men with severe underlying diseases and functional impairments,

During the 5-year study period, 40 MSSA and 28 MRSA infections were acquired by NHCU residents. Twelve to 19 S aureus infections occurred each year. S aureus accounted for 13% to 17% of all NHCU-acquired infections during the years of study, occurring with a frequency of 0.29 to 0.47 infections per 1,000 resident-care days. MRSA infections, first detected in 1988, accounted for an increasing percentage of S aureus infections in subsequent years, but this increase had little effect on the facility's overall infection rates, the composite S aureus infection rates, or the types of infections observed. MSSA and MRSA infections acquired in the NHCU were comparable. Both affected patients with severe underlying diseases and functional impairments. Pneumonia, urinary tract infections, skin and soft tissue infections, and conjunctivitis were the types of infections observed most frequently, accounting for 28%, 25%, 22%, and 15% of all S aureus infections, respectively. Four bacteremic infections occurred in the MSSA group, and five in the MRSA group (P=.47). Four of the MSSA and three of the MRSA infections resulted in death (P= 1.0). Nine of the MSSA and 12 of the MRSA infections resulted in the patient's transfer to the associated acute care hospital for additional care (P= .13).

In the NHCU setting, MSSA and MRSA infections were similar in terms of the types of residents affected, the sites involved, and the frequency of adverse outcomes. The entry of MRSA into the facility appeared to have no effect on the subsequent experience with NHCU-acquired infections caused by S aureus.

To characterize disposal-related sharps injuries.

A three-part study including (a) descriptive analysis of disposal-related injuries in a l-year period, (b) 4:l matched case-control study of nurses injured while using sharps disposal containers, and (c) survey to solicit opinions of users of containers.

An 1,181-bed teaching hospital in New York City.

For epidemiologic analyses, persons with self-reported injuries identified via New York State and Occupational Safety and Health Administration forms and control nurses without self-reported injuries. For survey, convenience sample of hospital nurses, laboratory workers, and maintenance workers.

Circumstances of injuries determined by study questionnaires. Employee opinions obtained by questionnaires and discussions during small group sessions.

Three hundred sixty-one persons reported sharps injuries, of whom 72 (20%) had disposal-related injuries. Persons with disposal-related injuries included four hospital visitors and one patient. Of 67 disposal-related injuries among employees, 25 (37%) directly involved use of a sharps disposal container. Significant risk factors for injury included container height greater than 4 ft above the floor, distance less than 5 ft from site of sharp object use to nearest container, and lack of attendance at universal precautions inservice classes. Survey groups involved 69 employees who identified a variety of preferred features for sharps disposal containers.

Disposal of sharp objects is an important cause of sharps injuries. Ergonomic factors, worker education, and appropriate container design should be considered in injury prevention strategies. Relevant guidelines and regulations are lacking and are needed.

To evaluate an outbreak of fever and hypotension after cardiac surgical procedures and the role of polygeline, a plasma expander.

Unmatched case-control study.

A six-bed cardiac surgery intensive care unit (SICU) of the Hospital Clinic of Barcelona (Spain), a 940-bed public teaching hospital.

Eight cases and 25 control patients admitted to the SICU over a 4-week epidemic period.

Development of hypotension (systolic blood pressure ≤ 90 mm Hg or a drop of 40 mm Hg from baseline systolic blood pressure) and fever (axillary temperature >38.5°C) within 24 hours of a cardiac surgical procedure.

The single risk factor significantly different between cases and controls was the total volume of polygeline used throughout the surgical procedure for extracorporeal circulation: a median of 1,250 mL (mean, 1,312.5 ± 842.5 mL) in cases versus 500 mL (mean, 566.0 ± 159.9 mL) in controls (P = .0029). By multiple logistic regression analysis, polygeline use was the single risk factor significantly related to the outcome (odds ratio, 8.75; CI95, 1.36 to 56.2; P= .01). Neither blood cultures from patients nor cultures of the polygeline used yielded growth of any microorganism. Stopping use of the implicated polygeline lot controlled the outbreak.

Use of polygeline was associated with an outbreak of fever and hypotension in a SICU. Information from the manufacturer indicated the likelihood of contamination of the product with Bacillus stearothermophilus components. The manufacturer has since changed the production and control processes, and no further adverse events have been seen.

To describe the incidence and types of first Hickman catheter-related infection (HCRI) in cancer patients and to identify indicators for catheter removal.

Retrospective cohort study.

A regional, tertiary, referral cancer center and its supportive care university teaching hospital.

A retrospective review was conducted of 316 consecutive adult oncology patients who underwent Hickman catheter placement from 1986 to 1990 at a regional oncology center. HCRI was determined on the basis of clinical information incriminating the Hickman catheter as the source of infection. Patient characteristics and data about HCRIs (exit site cellulitis, tunnel infection with concomitant exit site cellulitis, bloodstream infection, and exit site cellulitis with bloodstream infection) were abstracted from patient medical records. Subsequently, univariate and multivariate analyses for the risk of HCRI and catheter removal were completed.

The incidence of first HCRI was 5.98 infections per 1,000 catheter days. Overall, 156 (49%) of 316 patients developed their first HCRI prior to catheter removal. The median time to HCRI was 90 days. Male gender (P= .0004) and hematologic malignancy (P= .0001) emerged as significant risk factors for HCRI in the univariate analysis. A Cox model verified that male gender (P=.02) and hematologic malignancy (P= .004) were associated with an enhanced risk of HCRI. There were 35 exit site infections (23%), three infections of the tunnel and the exit site (2%)) 80 bloodstream infections (51%), and another 38 bloodstream infections with concomitant exit site infections (24%). The incidence of bloodstream infection was 3.05 per 1,000 catheter days. Gram-positive pathogens outnumbered gram-negatives and fungi, with Staphylococcus epidermidis being most common. Fifty (32%) of 156 HCRIs resulted in catheter removal. Predictors of Hickman catheter removal in the univariate analysis were bloodstream infection (P= .046) and pathogen type (P= .006). Multiple regression analysis suggested that having a gram-negative (P= .014) or fungal (P= .057) pathogen was the most important factor for catheter removal.

These data suggest that first HCRIs occur more commonly in male patients with hematologic malignancies than in patients with solid tumors. The removal of Hickman catheters in oncology patients probably is predicated on the causative pathogen, but further investigations are necessary to delineate this issue.

To study the spread of strains of Enterobacter aerogenes in our hospital in 1992 and 1993 by using two genotypic markers, and to evaluate these methods for the epidemiological investigation of this species.

Ribotyping (using two endonucleases) and arbitrarily primed (AP)-PCR (using two different 10-mer primers) were applied to the epidemiological typing of clinical strains of E aerogenes isolated from hospitalized patients.

The intensive care unit (ICU; 5 patients, 13 isolates), nephrology units (3 patients, 5 isolates), and surgery units (2 patients, 2 isolates) of the university hospital of Saint-Etienne (France).

Eight epidemiologically unrelated isolates, chosen as controls, exhibited distinct profiles, both by AP-PCR and ribotyping. Two clones of E aerogenes circulated in the ICU; both were isolated successively from samples of a single patient who stayed in the unit for almost 1 year. A third clone was recovered from patients of surgery units. A fourth clone was shown to have infected patients of nephrology units.

Ribotyping and AP-PCR appear to be reliable methods for typing E aerogenes strains implicated in nosocomial infection. The spread of independent clones of E aerogenes in different units of our hospital in 1992 and 1993 was demonstrated by both methods. This study emphasizes the need to choose the endonucleases or primers with care to obtain high discriminatory results in genotypic investigations.

To evaluate engineering control measures to prevent nosocomial transmission of diseases such as tuberculosis, we studied four portable high-efficiency air filtration units, including three high-efficiency particulate air (HEPA) filtration units, for their ability to remove aerosolized particles.

Studies were conducted in either a non-ventilated aerosol chamber or in a hospital isolation room that met CDC guidelines for TB control (negative pressure, ≧6 air changes per hour, air exhausted directly to the outside). The rooms were challenged with aerosolized mineral oil in the size range of 0.3 to 5.0 μm at levels 10 to 20 times the normal airborne particle load in the room at baseline. Airborne particles were counted with a laser counter capable of simultaneously measuring sizes ≧ = 0.3, ≧ 0.5, ≧ 1.0, and ≧ 5.0 μm. Experimental runs were conducted with the filtration units in the center or comer of the chamber or room, and the particle counter in the center of the room or at the exhaust vent.

Portable filtration units were effective in accelerating the removal of aerosolized submicron particles. In the nonventilated room, time required by the various portable filtration units for removal of 90% of aerosolized particles (≧ 0.3 μm) ranged from a low of 5 to 6 minutes to a high of 18 to 31 minutes, compared to the control (no filtration unit), >171 minutes. In the hospital room, individual filtration units removed 90% of aerosolized particles ( ≧ 0.3 μm) in times ranging from 5 to 8 minutes to 9 to 12 minutes, compared to the control (no filtration unit), 12 to 16 minutes. The location of the portable filtration unit (center versus comer) did not affect the clearance rate of airborne particles.

Our data indicate that portable filtration units can rapidly reduce levels of airborne particles similar in size to infectious droplet nuclei and, therefore, may aid in reducing the risk of tuberculosis exposure.

To reduce the risk of needlestick injuries to laboratory workers.

Continuous Quality Improvement (CQI) tools were applied to data collected on the number of blood gas syringes that arrived in the laboratory with needles still attached and to the reasons for these occurrences.

A clinical chemistry department within a 900-bed tertiary referral university teaching hospital.

Clinical chemistry laboratory staff and medical staff responsible for sending syringes with needles still attached.

Changing to a preheparinized blood gas syringe that included a syringe cap within the packaging.

Fivefold reduction in the number of syringes arriving in the laboratory with needles still attached.

The risk of needlestick injury to laboratory workers can be reduced by provision to clinical staff of preheparinized blood gas syringes that include a syringe cap within the packaging. The techniques of CQI provide powerful tools for the identification, solving, and monitoring of safety-related issues within the healthcare environment.

To report the results of an 8-year analysis of percutaneous injuries (PI), to describe interventions to decrease these injuries, and to discuss future prevention strategies.

Using consistent methods, 881 percutaneous injury reports were reviewed, categorized, and analyzed from 1986 through 1993.

A 620-bed acute-care county teaching hospital located in San Jose, California, that is affiliated with Stanford University Medical School, Palo Alto, California.

Employees of Santa Clara Valley Medical Center who reported percutaneous injuries from 1986 through 1993.

Placement of needle disposal containers in all patient care areas, 1987; education, 1987 to present; communication of percutaneous injury analyses to all departments, 1988 to present; and safety product evaluation and purchases, 1991 to present.

The total number of PI decreased by 65% (P=.0007) from 1986 through 1993. Recapping injuries decreased from 1986 through 1993 by 88% (P<.0002); interventions that included convenient placement of needle disposal containers and consistent annual education may have contributed to this decrease. Injuries from manipulating intravenous lines or heparin locks decreased in 1992 (P<.03) after purchase of a needleless system for intravenous lines. Injuries from improper disposal or from abrupt patient movement did not decrease significantly over the 8-year period.

This institution has conducted percutaneous injury analysis for 8 years, utilizing consistent reviewers and categorization methods. Successful interventions have reduced recapping injuries, injuries from manipulating intravenous lines/heparin locks, and the overall numbers of PI. The categories of “Improper Disposal” and “Patient Moved Abruptly” present challenges for future reductions, as well as the recently identified problem of staff not using available safety devices or using them improperly.