To evaluate the risk of nosocomial transmission of parvovirus B19 (B19) infection to healthcare workers (HCWs) exposed to patients with transient aplastic crisis (TAC) caused by acute B19 infection.

Cohort study.

1,000-bed, urban teaching hospital in Atlanta, Georgia.

Eighty-seven exposed HCWs who cared for two patients with TAC prior to the time they were isolated and a comparison group of 88 unexposed HCWs from wards or clinics where the patients did not receive care.

Self-administered questionnaire on hospital contact with index patients, B19 community risk factors, and signs and symptoms suggestive of B19 disease. Serology for B19-specific IgM and IgG antibodies measured by antibody-capture enzyme-linked immunosorbent assay.

1 (3.1%) of the 32 nonimmune exposed HCWs had serologic evidence of recent B19 infection compared to 3 (8.1%) of the 37 nonimmune HCWs in the comparison group (P=.6). In a subgroup analysis of exposed HCWs who cared for index patients during the time when the virus load was expected to be greatest, a recent infection rate of 5.8% (1/17) was found among nonimmune HCWs.

The finding of similar rates of recent infection in nonimmune exposed and unexposed HCWs suggests that transmission to HCWs did not occur, despite failure to place the patients in isolation at the onset of hospitalization.

To determine the annual cost of implementing and maintaining a respiratory personal protective equipment (PPE) program at an urban hospital.

St Clare's Hospital and Health Center, a 250-bed hospital in Manhattan that treats 60 to 100 cases of tuberculosis annually.

Review of Purchasing Department records for all masks acquired by the hospital from 1992 to 1995, and an estimate of administrative time spent developing and implementing the guidelines recommended by various agencies during the study interval.

Respiratory isolation was provided for 6,360 to 10,883 days annually during the 4-year interval. Yearly costs for the PPE program ranged from $86,560 to $175,690. Of note, the daily cost for a respiratory isolation day decreased dramatically between 1994 and 1995 ($25/day to $13/day), when the high-efficiency particulate air-filter (HEPA) respirator was used by all staff. The decrease occurred because of lower administrative costs and a sharp decrease in the numbers of HEPA units purchased. Objective measures of worker compliance with HEPA respirators demonstrated the decrease was not due to less HEPA use but rather that employees were using each HEPA unit for several weeks, as recommended.

We found a significant decrease in cost in the second year of our HEPA program due to increasing employee familiarity with the program. Newly approved, cheaper, but less durable, N-95 masks are unlikely to withstand multiple wearings and may be discarded after a few uses. Thus, cheaper masks may result in a more expensive PPE program.

To determine the cost of nonrespirator-related tuberculosis (TB) control measures at several hospitals, following publication of the Centers for Disease Control and Prevention (CDC)'s revised TB infection control guidelines.

Infection control (IC) and TB coordinators obtained cost information on tuberculin skin-test (TST) programs, addition of IC and employee health service (EHS) personnel, and the retrofit or new construction of environmental controls.

Four hospitals with, and one community hospital without, prior nosocomial multidrug-resistant TB transmission.

During the study period, the TST program costs remained constant at four of five hospitals and increased at one hospital (median 1994 TST program cost: $5,568; range, $2,393-$44,902). Additional IC or EHS personnel were hired at four of five hospitals (median cost increase, $125,500; range, $63,000-$228,000). The median cost of new construction or new equipment purchases (ie, sputum induction booths, ultraviolet lights, or portable high-efficiency particulate air filters) at study hospitals was $163,000 (range, $45,000-$524,000) and $70,000 (range, $31,000-$93,000), respectively.

Costs associated with implementing control measures similar to those recommended in the CDC TB IC guidelines varied widely by hospital. Engineering controls involved the largest capital outlay, but increases in personnel were the largest continuing cost. These costs represent improvements made to upgrade selected aspects of hospital TB control programs, not the cost of an optimal TB control program.

To determine the rates and routes of Acinetobacter baumanii colonization and pneumonia among ventilated patients in a surgical intensive-care unit (SICU) before and after architectural modifications.

A nonsequential study comparing two groups of patients. All isolates from systematic and clinical samples were genotyped by pulsed-field gel electrophoresis (PFGE). Records of patients hospitalized during the first and second periods were reviewed and findings were compared. Between the two periods, the SICU was remodeled from enclosed isolation rooms and open rooms to only enclosed isolation rooms with handwashing facilities in each room.

All patients hospitalized and mechanically ventilated for more than 48 hours in the 15-bed SICU of the University Hospital of Besançon (France).

For the first and second periods, the rates of colonization were, respectively, 28.1% and 5.0% of patients (P<10−7; relative risk [RR], 2.23; 95% confidence interval [CI95], 1.8-2.75) and the specific rates of bronchopulmonary (BP) colonization were, respectively, 9.1 and 0.5 per 1,000 days of mechanical ventilation (P<10−5). Seven major PFGE isolate types were identified, 4 of which were isolated from 44 of the 47 colonized or infected patients. Logistic regression analysis showed that colonization was not associated with patient characteristics.

Conversion from open rooms to isolation rooms may help control nosocomial BP tract acquisition of A baumanii in mechanically ventilated patients hospitalized in an SICU.

To study the possible role of contaminated environmental surfaces as a reservoir of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals.

A prospective culture survey of inanimate objects in the rooms of patients with MRSA.

A 200-bed university-affiliated teaching hospital.

Thirty-eight consecutive patients colonized or infected with MRSA. Patients represented endemic MRSA cases.

Ninety-six (27%) of 350 surfaces sampled in the rooms of affected patients were contaminated with MRSA. When patients had MRSA in a wound or urine, 36% of surfaces were contaminated. In contrast, when MRSA was isolated from other body sites, only 6% of surfaces were contaminated (odds ratio, 8.8; 95% confidence interval, 3.725.5; Pく.0001). Environmental contamination occurred in the rooms of 73% of infected patients and 69% of colonized patients. Frequently contaminated objects included the floor, bed linens, the patient's gown, overbed tables, and blood pressure cuffs. Sixty-five percent of nurses who had performed morning patient-care activities on patients with MRSA in a wound or urine contaminated their nursing uniforms or gowns with MRSA. Forty-two percent of personnel who had no direct contact with such patients, but had touched contaminated surfaces, contaminated their gloves with MRSA.

We concluded that inanimate surfaces near affected patients commonly become contaminated with MRSA and that the frequency of contamination is affected by the body site at which patients are colonized or infected. That personnel may contaminate their gloves (or possibly their hands) by touching such surfaces suggests that contaminated environmental surfaces may serve as a reservoir of MRSA in hospitals.

To assess the effectiveness of a multi-faceted infection control strategy in limiting the nosocomial transmission of respiratory syncytial virus (RSV) infection to patients in a bone marrow transplant (BMT) unit.

Before/after trial.

University-affiliated tertiary cancer center.

Adult BMT recipients hospitalized during two consecutive wintertime community outbreaks of RSV infection.

An infection control strategy against nosocomial RSV infection was implemented in the BMT unit in February 1993. The strategy involved prompt identification, isolation, and cohorting of RSV-infected patients; prompt therapy with aerosolized ribavirin; use of masks and gloves by anyone entering an infected BMT patient's room; screening visitors for respiratory symptoms; restricting visitation by all children under 12 years of age and all family members and other visitors with RSV symptoms; and restricting symptomatic hospital staff from working in the BMT unit.

After implementation of the multifaceted infection-control strategy, there were four cases of nosocomial RSV infection in 3,870 patient days (incidence density, 1.0 case/1,000 patient days) compared with 14 cases of nosocomial RSV infection in 3,152 patient days (incidence density, 4.4 cases/1,000 patient days) during the 1992-1993 RSV season (rate ratio, 4.4; 95% confidence interval [CI95], 1.4-17.9; P<.01). This decrease in incidence occurred despite a comparable prevalence of community-acquired RSV cases between the two seasons (2.2% vs 3.2% in 1992-1993 and 1993-1994, respectively; prevalence ratio, 0.7; CI95, 0.2-2.1; P=0.5)

Institution of a multifaceted infection control strategy significantly reduced the frequency of nosocomial RSV infection in a high-risk group of adult BMT recipients

To determine risk factors for patients whose cultures grew Stenotrophomonas maltophilia.

Retrospective case-control study of 60 patients with cultures positive for S maltophilia, matched by specimen site to 120 controls whose cultures grew other gram-negative aerobic bacteria.

University medical center.

S maltophilia was identified from the following sites: respiratory (36), wound (13), urinary (6), blood (4), and cerebral spinal fluid (1). By univariate analysis, cases had a higher risk of exposure than controls for ampicillin (P<.001), gentamicin (P<.001), vancomycin (P=.001), metronidazole (P=.003), piperacillin (P=.007), cefotaxime (P=.014), ceftazidime (P=.017), ciprofloxacin (P=.030), tobramycin (P=.040), and chronic respiratory disease (P=.024). Length of time foreign objects were in place prior to positive culture differed significantly between cases and controls only for endotracheal tubes in patients with respiratory isolates (median number of days: 12.5 for cases, 5 for controls; P=.007). For patients with urinary tract infections, having a urinary catheter increased the odds of infection 10 times over controls. Exposures found by multivariate analysis to be significantly more prevalent in cases than controls included ampicillin, cefotaxime, erythromycin, gentamicin, metronidazole, piperacillin, tobramycin, chronic respiratory disease, and female gender. Odds ratios were >1 indicating higher risk for cases, except for erythromycin, which had an odds ratio <1.

The primary risk factor associated with isolation of S maltophilia was antibiotic use. For patients with pulmonary infections, chronic respiratory disease and length of time an endotracheal tube was in place also contributed to the risk. This suggests that judicious use of antibiotics may prevent some cases of S maltophilia infection.

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.

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.

A 13-hospital health system in the Midwest.

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.

Considerable variation existed in the TB control policies and procedures between hospitals, but employee TB skin-test conversion rates were low in all settings.

To investigate a mixed Salmonella heidelberg and Campylobacter jejuni foodborne outbreak in a nursing home.

Retrospective cohort study with a nested case-control design. Cases were defined by positive stool-culture results. Controls needed to be both asymptomatic and culture-negative.

Residents of a 580-bed nursing home in Brooklyn, New York.

Of the 580 residents, 119 (21%) developed illness. Of the 93 symptomatic patients who submitted specimens, cultures were positive for S heidelberg in 24 (26%), C jejuni in 14 (15%), and both microorganisms in 25 (27%).

Only the pureed diet was associated highly with infection by either Salmonella (odds ratio [OR], 17.6; 95% confidence interval [CI95], 4.8-68.7; P<.001), Campylobacter (OR, 13.3; CI95, 3.2-59.2; P<.001), or both organisms (OR, 8.9; CI95, 2.7-30.3; P<.001). Among the 52 pureed foods served during the 5 days before the outbreak, five meat or poultry items were associated most strongly with culture positivity.

Of these five meat items, only a chopped-liver salad was implicated by the two employees reporting illness. A reported food-handling error occurred when ground, cooked chicken livers were placed in a bowl containing raw chicken-liver juices.

Recommendations for proper cleaning and sanitizing of kitchen equipment to prevent cross-contamination between raw and cooked foods.

Mixed foodborne outbreaks occur rarely. During this outbreak, contamination of a single food item with multiple bacterial pathogens was the likely source of transmission. Improper food-handling techniques that promote growth of one microorganism also allow growth of other pathogens that may be present. Because different sources and routes of transmission may be implicated for different pathogens, specific preventive measures may vary depending on the organisms involved.

To evaluate the effectiveness of specific infection control measures on the incidence of Clostridium difficile-associated diarrhea (CDAD) and to identify risk factors for its development.

370-bed, tertiary-care teaching hospital with approximately 12,000 to 15,000 admissions per year.

Several infection control measures were implemented in 1991 and 1992, and the attack rates of CDAD were calculated quarterly. Antibiotic use for 1988 through 1993 was analyzed. A case-control study was conducted from January 1992 to December 1992 to identify risk factors for acquisition of CDAD.

From 1989 to 1992, the attack rate of CDAD increased from 0.49% to 2.25%. An increase in antibiotic use preceded the rise in the incidence of CDAD in 1991. Despite implementation of various infection control measures, the attack rate decreased to 1.32% in 1993, but did not return to baseline. Ninety-two cases and 78 controls (patients with diarrhea but with negative toxin assay) were studied. By univariate analysis, history of prior respiratory tract infections (odds ratio [OR], 3.6; 95% confidence interval [CI95], 1.2-10.4), the number of antibiotics, and the duration of exposure to second-generation cephalosporins (OR, 3.55; CI95, 1.47-9.41) and to ciprofloxacin (OR, 7.27; CI95, 1.13-166.0) were related significantly to the development of CDAD. By stepwise logistic regression analysis, only exposure to antibiotics and prior respiratory tract infections (P=.0001 and .0203, respectively) were found to be significant.

Antibiotic pressure might have contributed to failure of infection control measures to reduce the incidence of CDAD to baseline.