To determine the microbial load found on used critical medical devices (5 spinal anesthesia needles, 21 catheters, and 28 sheaths) prior to sterilization and to evaluate the effectiveness of hydrogen peroxide gas plasma against inoculated Bacillus subtilis var giobigii (American Type Culture Collection 9372) spores.

Membrane filter and pour-plate methods were applied to estimate total microbial loads (aerobic and anaerobic, mesophilic and thermophilic, vegetative and spore forms). Spinal anesthesia needles (102 units) and sheath components (61 units) were inoculated with a suspension of B subtilis spores. After drying, the devices were sterilized with hydrogen peroxide gas plasma.

Higher counts of aerobic, mesophilic, and fungal organisms were recovered when the drying period was insufficient. Anaerobic spores were not found in any analyzed presterilization items. The hydrogen peroxide gas plasma effected a 5 to 7 log10-fold reduction in B subtilis spore counts in well-dried needles and sheath components.

The success of hydrogen peroxide gas plasma sterilization depends mostly on educating the staff to assure well-cleaned and dried reusable medical devices, allowing penetration of the hydrogen peroxide gas plasma into the critical points of the items and providing a reduction in organisms.

To determine the cost-effectiveness of a policy of screening high-risk patients for methicillin-resistant Staphylococcus aureus (MRSA) colonization on admission to hospital.

980-bed university-affiliated tertiary-care hospital.

Between June 1996 and May 1997, patients directly transferred from another hospital or nursing home, or who had been hospitalized in the previous 3 months, were screened for MRSA within 72 hours of hospital admission.

Nasal, perineal, and wound swabs were obtained for MRSA screening using standard laboratory methods. Laboratory and nursing costs associated with screening patients for MRSA on admission to hospital were calculated. The costs associated with the implementation of recommended infection control measures for patients with MRSA also were determined.

3,673 specimens were obtained from 1,743 patients. MRSA was found on admission in 23 patients (1.3%), representing 36% of the 64 patients with MRSA identified in the hospital during the year. MRSA-colonized patients were more likely to have been transferred from a nursing home (odds ratio [OR], 6.4; P=.04) or to have had a previous history of MRSA colonization (OR, 13.1; P=.05). Laboratory and nursing costs were found to be $8.34 per specimen, for a total cost of $30,632 during the year. The average cost of implementing recommended infection control measures for patients colonized with MRSA was approximately $5,235 per patient.

If early identification of MRSA in colonized patients prevents nosocomial transmission of the organism to as few as six new patients, the screening program would save money.

To estimate the incidence of methicillin-resistant Staphylococcus aureus (MRSA) in patients hospitalized in French public hospitals.

A 2-month survey that included 163,573 patients and 140,114 admissions.

Forty-three public or public-affiliated hospitals throughout France, including 12 university-affiliated hospitals. Information was recorded on all patients having MRSA recovered from culture of any clinical sample.

The overall median incidence rate (per 1,000 admissions) of clinically detected MRSA was 5.9 (range, 1.8-15.8); median rates were similar in hospitals affiliated or not affiliated to universities (6.4 and 5.9, respectively). Smaller unaffiliated hospitals (<500 beds) had higher MRSA incidence rates (mean, 7.2) than larger (>500 beds) unaffiliated hospitals or university hospitals (mean, 6.7 and 6.1, respectively). The incidence density (per 1,000 patient-days) of MRSA was higher in intensive-care units [ICUs] 2.39/1,000) than in surgical (0.80/1,000) and medical (0.70/1,000) wards, respectively; comparable rates were recorded in rehabilitation units (0.67/1,000), whereas in long-term-stay units, the incidence density of MRSA was 0.27/1,000 patient-days. Of 958 MRSA isolates, 660 (69%) also were resistant to all aminoglycosides. In 411 (43%) of 958 patients, the MRSA isolate was considered imported (ie, first recovered within 72 hours of the patient's admission to the unit). More than one half (53%) of imported cases were transfer patients from other hospitals, and 17% originated from ICUs.

MRSA is extensive in French hospitals. All categories of hospitals are involved to a similar extent, and there is intense circulation of patients colonized or infected with MRSA between units and hospitals. Containment of MRSA would mandate increasing resources devoted to infection control, especially in smaller hospitals, and control programs should involve notification of carriers and screening of patients at risk of MRSA carriage on admission to detect carriers and to implement isolation precautions rapidly.

To compare the microbial contamination rate of infusate in the intravenous tubing of newborns receiving lipid therapy, replacing the intravenous delivery system at 72-hour versus 24-hour intervals.

Infants requiring intravenous lipid therapy were randomly assigned to have intravenous sets changed on a 72- or a 24-hour schedule, in a 3:1 ratio, in order to compare the infusate contamination rates in an equivalent number of tubing sets.

A 35-bed, teaching, referral, neonatal intensive-care unit (NICU).

All neonates admitted to the NICU for whom intravenous lipid was ordered.

Patients were randomized in pharmacy, on receipt of the order for intravenous lipid therapy, to either 72- or 24-hour administration set changes, and followed until 1 week after discontinuation of lipids or discharge from the NICU. Microbial contamination of the infusate was assessed in both groups at the time of administration set changes. Contamination rates were analyzed separately for the lipid and amino acid-glucose tubing sets. Patient charts were reviewed for clinical and epidemiological data, including birth weight, gestational age, gender, age at start of lipid therapy, duration of parenteral nutrition, and type of intravenous access.

During the study period, 1,101 and 1,112 sets were sampled in the 72- and 24-hour groups, respectively. Microbial contamination rates were higher in die 72-hour group than the 24-hour group for lipid infusions (39/1,101 [3.54%] vs 15/1,112 [1.35%]; P=.001) and for amino acid infusions (12/1,093 [1.10%] vs 4/1,103 [0.36%]; P=.076). Logistic regression analysis controlling for birth weight, gestational age, and type of venous access showed that only the tubing change interval was significanfly associated with lipid set contaminations (odds ratio, 2.69; P=.0013). The rate of blood cultures ordered was higher in die 72-versus the 24-hour group (6.11 vs 4.99 per 100 patient days of total parenteral nutrition; P=.017), and a higher proportion of infants randomized to the 72-hour group died (8% vs 4%; P=.05), although the excess deaths could not clearly be attributed to bacteremia.

Microbial contamination of infusion sets is significantiy more frequent with 72- than witii 24-hour set changes in neonates receiving lipid solutions. This may be associated with an increased mortality rate.

To evaluate and compare the risk of long-term central venous catheter (CVC) infection in human immunodeficiency virus (HIV)-infected and cancer patients.

Prospective multicenter cohort study based on active surveillance of long-term CVC manipulations and patient outcome over a 6-month period.

Services of infectious diseases and oncology of 12 university hospitals in Paris, France.

In 1995, all HIV and cancer patients with solid malignancy were included at the time of long-term CVC implantation.

Overall, 31.6% of long-term CVC infections were identified in 32% of 201 HIV and 5% of 255 cancer patients. Most were associated with bacteremia, most commonly coagulase-negative staphylococci. The long-term CVC time-related infection risk was greater in HIV than in cancer patients (3.78 vs 0.39 infections per 1,000 long-term CVC days; P<.001). The independent risk factors of long-term CVC infection were as follows: in HIV patients, frequency of long-term CVC handling and neutropenia; in cancer patients, poor Karnofsky performance status; in both HIV and cancer patients, recent history of bacterial infection. The risk of long-term CVC infection was similar for tunneled catheters and venous access ports in each population.

Prevention of long-term CVC infection should focus first on better sterile precautions while handling long-term CVC, especially in HIV patients who have frequent and daily use of the long-term CVC.

To determine which influenza vaccination program characteristics were associated with high resident vaccination rates in Canadian long-term–care facilities (LTCFs).

A cross-sectional survey consisting of a mailed questionnaire conducted in spring 1991.

All 1,520 Canadian LTCFs for the elderly with at least 25 beds.

The mean overall influenza vaccination rate in the 1,270 (84%) responding facilities was 79%. In multivariate analysis, the variables significantly associated with increased vaccination rates were: a single nonphysician staff person organizing the program, having more program aspects covered by written policies, the offering of vaccine to all residents, a policy of obtaining consent on admission that was durable for future years rather than repeating consent annually, and automatically administering vaccine to residents whose guardians could not be contacted for consent. Any encouragement to staff to be vaccinated had a significant impact on staff vaccination rates.

Well-organized influenza vaccination programs increase the influenza vaccination rates of residents in Canadian LTCFs. Facilities need to develop resident vaccination programs further and to focus on vaccinating staff.

To determine the seroconversion rate after varicella immunization of healthcare workers (HCWs) and the effect of seroconversion rate on current cost-based recommendations for universal vaccination.

A voluntary vaccination program for HCWs was performed at a tertiary-care cancer center in New York City. A commercial latex agglutination assay was used to test postvaccination antibody response. Costs for vaccination and postvaccination serological testing were compared to potential costs of postexposure employee furloughs.

Of 263 seronegative HCWs, 96 (36.5%) began the vaccine program. Thirty-nine HCWs received only one dose of vaccine. Seven returned for follow-up antibody testing, of whom 4 were seropositive. Of the 57 HCWs who received two doses, 38 returned for follow-up serology. Thirty-one (81.6%) HCWs were seropositive for varicella-zoster virus antibodies, and seven HCWs (18.4%) remained seronegative. Total cost of vaccination for all 263 seronegative HCWs was estimated and compared to the cost of varicella-related furloughs at our institution.

We found a considerably lower rate of vaccine-induced seroconversion at our hospital compared to that of the published literature. Despite this finding, universal varicella vaccination remained an extremely cost-effective alternative to the furloughing of exposed, seronegative HCWs. Projected hospital savings exceeded $53,000 in the first year after vaccination alone.

To evaluate efficacy of laminar airflow facilities plus high-efficiency particulate air (HEPA) filtration and HEPA filtration alone in preventing environmental Aspergillus contamination during hospital renovation. To show the usefulness of environmental surveillance to facilitate protection of patients at risk for invasive pulmonary aspergillosis.

Prospective sampling of air and surfaces for Aspergillus conidia during 2-year period.

A hematological department adjacent to building renovation at a university hospital.

1,047 air samples and 1,178 surface samples were collected from January 1996 to December 1997. Significantly more air samples were positive for Aspergillus species during the period of building renovation than during the periods before and after renovation in a unit without a protected air supply adjacent to the building work area (51.5% vs 31.7%; odds ratio [OR], 2.3; 95% confidence interval [CI95, 1.4-3.7; P<.001). A major increase in the frequency of positive air samples was also found in another adjacent unit that was protected with HEPA filtration alone (from 1.8% to 47.5%; OR, 48.9; CI95,12-229; P<10-7). In addition, in this unit, the mean count of Aspergillus conidia in positive air samples increased significantly during construction (4 colony-forming units [CFU]/m3 to 24.7 CFU/m3; P=.04) and the proportion of positive surface samples showed a significant increase during renovation (from 0.4% to 9.7%; OR, 28.3; CI95, 3.4-623; P=104). However, none of 142 air samples collected during renovation in the area protected with laminar airflow plus HEPA filtration showed Aspergillus conidia. In a unit distant from the building renovation site, the results of air and surface samples were not affected by renovation.

This study showed a strong association between building renovation and an increase in environmental Aspergillus contamination. Results confirmed the high efficacy of laminar airflow plus HEPA filtration and a high air-change rate. Although filtration with HEPA was effective during normal conditions, it alone was unable to prevent the rise of Aspergillus contamination related to building renovation. This study emphasized the necessity of an environmental survey of airborne contamination related to construction, to facilitate prevention of nosocomial aspergillosis outbreaks. A standardized protocol for aerobiological surveillance is needed.