Results of a comprehensive infection control program for reducing surgical-site infections in coronary artery bypass surgery.

OBJECTIVE: To evaluate the efficacy of a comprehensive infection control program on the reduction of surgical-site infections (SSIs) following coronary artery bypass graft (CABG) surgery. DESIGN: Prospective cohort study. SETTING: 1,000-bed tertiary-care hospital. PATIENTS: Persons undergoing CABG with or without concomitant valve surgery from April 1991 through December 1994. INTERVENTIONS: Prospective surveillance, quarterly reporting of SSI rates, chlorhexidene showers, discontinuation of shaving, administration of antibiotic prophylaxis in the holding area, elimination of ice baths for cooling of cardioplegia solution, limitation of operating room traffic, minimization of flash sterilization, and elimination of postoperative tap-water wound bathing for 96 hours. Logistic regression models were fitted to assess infection rates over time, adjusting for severity of illness, surgeon, patient characteristics, and type of surgery. RESULTS: 2,231 procedures were performed. A reduction in infection rates was noted at all sites. The rate of deep chest infections decreased from 2.6% in 1991 to 1.6% in 1994. Over the same period, the rate of leg infections decreased from 6.8% to 2.7%, and of all SSI from 12.4% to 8.9%. The adjusted odds ratio (OR) for all SSIs for the end of 1994 compared to December 31, 1991, was 0.37 (95% confidence interval [CI95], 0.22-0.63). For deep chest and mediastinal infections, the adjusted OR comparing the same period was 0.69 (CI95, 0.28-1.71). CONCLUSIONS: We observed significant reductions in SSI rates of deep and superficial sites in CABG surgery following implementation of a comprehensive infection control program. These differences remained significant when adjusted for potential confounding covariables.

Use of personal protective equipment and operating room behaviors in four surgical subspecialties: personal protective equipment and behaviors in surgery.

OBJECTIVE: To evaluate Universal Precautions (UP) compliance in the operating room (OR). DESIGN: Prospective observational cohort. Trained observers recorded information about (1) personal protective equipment used by OR staff; (2) eyewear, glove, or gown breaks; (3) the nature of sharps transfers; (4) risk-taking behaviors of the OR staff; and (5) needlestick injuries and other blood and body-fluid exposures. SETTING: Barnes-Jewish Hospital, a 1,000-bed, tertiary-care hospital affiliated with Washington University School of Medicine, St Louis, Missouri. PARTICIPANTS: OR personnel in four surgical specialties (gynecologic, orthopedic, cardiothoracic, and general). Procedures eligible for the study were selected randomly. Hand surgery and procedures requiring no or a very small incision (eg, arthroscopy, laparoscopy) were excluded. RESULTS: A total of 597 healthcare workers' procedures were observed in 76 surgical cases (200 hours). Of the 597 healthcare workers, 32% wore regular glasses, and 24% used no eye protection. Scrub nurses and medical students were more likely than other healthcare workers to wear goggles. Only 28% of healthcare workers double gloved, with orthopedic surgery personnel being the most compliant. Sharps passages were not announced in 91% of the surgical procedures. In 65 cases (86%), sharps were adjusted manually. Three percutaneous and 14 cutaneous exposures occurred, for a total exposure rate of 22%. CONCLUSION: OR personnel had poor compliance with UP. Although there was significant variation in use of personal protective equipment between groups, the total exposure rate was high (22%), indicating the need for further training and reinforcement of UP to reduce occupational exposures.

Management and outcome of tuberculosis in two St Louis hospitals, 1988 to 1994.

OBJECTIVE: To describe management and outcome of tuberculosis (TB) and current practices for isolation in two urban hospitals in the Midwest. DESIGN: Retrospective cohort study. SETTING: Barnes Hospital and Jewish Hospital, tertiary-care and community hospitals affiliated with Washington University School of Medicine in St Louis, Missouri. PATIENTS: All adult patients with a positive culture for Mycobacterium tuberculosis from 1988 to 1994. RESULTS: 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%. CONCLUSIONS: 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.

Does clinical experience affect medical students' knowledge, attitudes, and compliance with universal precautions?

OBJECTIVE: To investigate differences in second-, third-, and fourth-year medical students' knowledge of bloodborne pathogen exposure risks, as well as their attitudes toward, and intentions to comply with, Universal Precautions (UP). DESIGN: Cross-sectional survey. PARTICIPANTS AND SETTING: Surveys about students' knowledge, attitudes, and intentions to comply with UP were completed by 111 second-year (preclinical), 80 third-year, and 60 fourth-year medical students at Washington University School of Medicine in the spring of 1996. RESULTS: Preclinical students knew more than clinical students about the efficacy of hepatitis B vaccine, use of antiretroviral therapy after occupational exposure to human immunodeficiency virus, and nonvaccinated healthcare workers' risk of infection from needlestick injuries (P<.001). Students' perceived risk of occupational exposure to bloodborne pathogens and attitudes toward hepatitis B vaccine did not differ, but preclinical students agreed more strongly that they should double glove for all invasive procedures with sharps (P<.001). Clinical students agreed more strongly with reporting only high-risk needlestick injuries (P=.057) and with rationalizations against using UP (P=.008). Preclinical students more frequently reported contemplating or preparing to comply with double gloving, wearing protective eyewear, reporting all exposures, and safely disposing of sharps, whereas students with clinical experience were more likely to report compliance. Clinical students also were more likely to report having "no plans" to practice the first three of these precautions (P<.001). CONCLUSIONS: Differences in knowledge, attitudes, and intentions to comply with UP between students with and without clinical experience may have important implications for the timing and content of interventions designed to improve compliance with UP.

Tuberculosis, hepatitis B, rubella, rubeola, and varicella infection and immunity among medical school employees.

OBJECTIVE: To assess baseline health status of a medical school employee population and to assess this population's acceptance of vaccination and other interventions to reduce risk of disease transmission. DESIGN: A retrospective review of an employee health records database for a 4-year period. SETTING: A large, urban university hospital. PARTICIPANTS: 5,007 employees screened by employee health for immunity to vaccine-preventable illnesses and tuberculosis. RESULTS: 9.4% of the employees had positive tuberculin skin tests, with a conversion rate of 6.4% for those who had negative tests within the previous 2 years. Two individuals were identified who had active pulmonary tuberculosis. Fewer than 10% of the individuals for whom isoniazid chemoprophylaxis was recommended completed the 6 months of therapy. Most clinical employees (96.1%) did not have a history of prior hepatitis B virus (HBV) infection or immunization, but 77% of them subsequently completed the vaccination series. Most employees with a negative history for infection with or immunization against rubella, rubeola, and varicella had serological evidence of immunity (90.2%, 97.9%, and 87.2%, respectively). CONCLUSIONS: Review of aggregate employee health databases may assist individuals who must establish strategies for prevention of occupational illness and disease transmission in this specialized setting. While many employees at risk for HBV complete the vaccination series, strategies for improving this rate could be helpful. Substantial work is needed to analyze reasons why so few individuals for whom isoniazid chemoprophylaxis is recommended complete the therapy, and strategies tailored to the impediments identified should be implemented.

Healthcare workers' attitudes and compliance with universal precautions: gender, occupation, and specialty differences.

We describe variations in healthcare workers' attitudes toward double gloving and reporting needlesticks, and in their readiness to comply with double gloving and hepatitis B vaccine. Differences related to occupation, specialty, and gender have implications for the need to tailor interventions for specific groups of healthcare workers to improve compliance with Universal Precautions.

Varied approaches to tuberculosis control in a multihospital system.

OBJECTIVES: To document the actual tuberculosis (TB) control policies and procedures in a nonoutbreak setting in a variety of hospitals. To determine if any particular practices are linked to higher rates of employee tuberculin skin-test conversion. DESIGN: Survey of hospital occupational health and infection control practitioners for the year 1994 regarding hospital TB policies. Review of hospital records to verify the number of patients with TB at each hospital and to verify the number of employees with positive tuberculin skin tests. Smoke-stick testing of negative-pressure ventilation rooms. SETTING: A 13-hospital health system in the Midwest. RESULTS: Hospitals ranged in size from 40 to 1,208 beds (median 220) and employed 150 to 6,500 workers (median 875). There were seven rural and six urban centers, including four teaching hospitals. All 13 hospitals had TB control plans, and all performed annual tuberculin skin testing on employees. Annual skin-test positivity rates ranged from 0% to 1.0% (median 0.3%). Negative-pressure ventilation rooms were available in 11 hospitals. The percentage of negative-pressure rooms with effective negative pressure ranged from 44% to 100% (median 95%). Three of the 13 hospitals used high-efficiency particulate air (HEPA) masks as primary personal respiratory protection, and 8 used dust-mist or dust-mist-fume masks. We found no relation between the type of face mask used, number of functional negative-pressure rooms, or hospital TB risk category, and employee skin-test conversion rates. CONCLUSIONS: Considerable variation existed in the TB control policies and procedures between hospitals, but employee TB skin-test conversion rates were low in all settings.

Issues complicating the implementation of postexposure prophylaxis.

Occupational exposures to blood-borne pathogens occur regularly in diverse settings and involve multiple groups of healthcare workers. Current compliance of healthcare workers with behavioral controls is poor, and additional engineering and work-practice controls for exposure prevention are inadequate and/or underutilized. Barriers to effective postexposure management include deficient knowledge and fear and denial among healthcare workers, the diverse risks associated with different exposures, the costs and personnel necessary for providing exposure management 24 hours a day, variable levels of expertise in postexposure prophylaxis strategies, and administrative requirements for standardized policies and procedures. In the current environment, healthcare institutions are largely ill equipped to provide timely and effective postexposure prophylaxis. Widespread worker education, simplified reporting mechanisms, and availability of prompt source and worker testing along with timely, free postexposure prophylaxis is central to an institution's postexposure program. Postexposure management programs should be comprehensive and provide standardized procedures, expand workers' access to postexposure prophylaxis by establishing responsible parties in diverse areas, disseminate program information to all workers, and ensure confidentiality in the care and follow-up of exposed workers. To implement such programs, it may be necessary to merge resources and link local management of exposures with regional expertise to provide up-to-date counseling in a rapidly changing field. Careful surveillance of occupational exposures is essential to evaluate program efficacy, direct prevention efforts, and to determine necessary resources to ensure continued successful delivery of postexposure prophylaxis.

Randomized prospective study of the impact of three needleless intravenous systems on needlestick injury rates.

OBJECTIVE: To determine the impact of three needleless intravenous systems on needlestick injury rates. DESIGN: Randomized controlled trial. SETTING: 1,000-bed tertiary-care Midwestern hospital. PARTICIPANTS: Nursing personnel from general medical, general surgical, and intensive-care units. INTERVENTIONS: From June 1992 through March 1994, a metal blunt cannula (MBC), two-way valve (2-way), and plastic blunt cannula (PBC) were introduced into three study areas, and needlestick injury rates were compared to three control areas using traditional needled devices. RESULTS: 24 and 29 needlestick injuries were reported in study and control areas. Intravenous-therapy-related injuries comprised 45.8% and 57.1% of injuries in each area. Thirty-seven percent and 20.7% of study and control area needlestick injuries were considered to pose a high risk of bloodborne infection. The 2-way group had similar rates of total and intravenous-related needlestick injuries compared to control groups. The PBC group had lower rates of total and intravenous-related needlestick injuries per 1,000 patient-days (rate ratios [RR], 0.32 and 0.24; 95% confidence intervals [CI95], 0.12-0.81 and 0.09-0.61; P = .02 and P = .003, respectively) and per 1,000 productive hours worked (RR, 0.11 and 0.08; CI95, 0.01-0.92 and 0.01-0.69; P = .03 and P = .005, respectively) compared to controls. CONCLUSIONS: Needlestick injuries continued in study areas despite the introduction of needleless devices, and risks of bloodborne pathogen transmission were similar to control areas. The PBC device group noted lower rates of needlestick injuries compared to controls, but there were problems with product acceptance, correct product use, and continued traditional device use in study areas. Low needlestick injury rates make interpretations difficult. Further studies of safety devices are needed and should attempt greater control of worker behavior to aid interpretation.

Follow-up evaluation of respiratory isolation rooms in 10 midwestern hospitals.

As a follow-up to a 1992 study or respiratory isolation, we studied compliance with recommendations for respiratory isolation through smokestick testing (1993) and surveys (1994). Effective negative pressure was demonstrated in 80 of 156 rooms and was associated with the presence of anterooms (P < .001). The proportion of surveyed hospitals periodically testing isolation rooms increased from 0% (1992) to 30% (1993) to 100% (1994; P < .001).

Nosocomial outbreak of gastroenteritis due to Salmonella senftenberg.

We describe a prolonged nosocomial outbreak of Salmonella senftenberg, an uncommon human pathogen. We detected 22 cases of infection due to S. senftenberg that occurred from March 1993 through November 1994 and involved 18 patients and four healthy employees. All infected persons had consumed food prepared by the hospital kitchen. The estimated attack rate for the period of the outbreak was 0.19-0.23 cases per 100,000 meals served. Infection control interventions included observation of food preparation, disinfection of kitchen devices, and education of food handlers. The consumption of lettuce (11 of 15 patients who could recount extended dietary histories vs. 4 of 20 controls; P = .005), cauliflower (5 of 15 vs. 0/20; P = .02), cottage cheese (4 of 15 vs. 0/20; P = .03), and deli turkey (8 of 15 vs. 0/20; P < .001) was associated with S. senftenberg infection. The isolates had identical antibiograms and pulsed-field gel electrophoretic patterns. Cultures of stool samples from food handlers as well as food items, kitchen devices, and kitchen surroundings were negative for S. senftenberg. Interruption of the outbreak occurred coincidentally with the institution of infection control measures. This prolonged outbreak of salmonellosis was probably related to contamination in the kitchen from turkey, with cross-contamination via equipment.

The epidemiology of chest and leg wound infections following cardiothoracic surgery.

The occurrence of wound infections following cardiothoracic surgery has significant implications. However, the epidemiology of all chest and leg wound infections is infrequently described, and the effects on morbidity, mortality, and cost of care remain undefined. We identified 182 superficial and deep chest and leg infections in 163 patients following 1,554 coronary artery bypass graft (CABG), valve, and CABG/valve procedures over 30 months. The overall infection rate was 11.7%; infections of specific sites involved in the 1,554 procedures occurred at the following rates: 3.1%, superficial chest wounds; 2.3%, deep chest wounds; 4.6%, superficial leg wounds; and 2.2%, deep leg wounds. Chest infection rates were similar for all procedures. Multiple infections occurred in 9.8% of patients and were associated with female sex, diabetes, and prolonged surgery (P < .05). Purulent drainage and fever were more common in chest infections; erythema and pain were more common in leg infections (P < .05). Staphylococcus aureus (32.9%), coagulase-negative staphylococci (27.4%), and Enterobacteriaceae (26.0%) were identified most commonly. Enterobacteriaceae were more commonly isolated from leg wounds (P < .05). Adverse outcomes included reexploration (20.9%), flap surgery (12.3%), and death (4.3%). All adverse outcomes were more commonly associated with deep chest infections (P < .05), but superficial chest and leg infections also had a substantial impact on cardiothoracic surgery-related morbidity. Studies are needed to define site-specific risk factors so that the full potential of prevention and control measures can be realized.