To evaluate the efficacy of a multistep cleaning method using a cleaner and a chemical disinfectant on blood-contaminated angiographic catheters and spinal needles intended to be sterilized by hydrogen peroxide gas plasma.

A mixture of radiopaque iodine contrast, bovine blood (plus ethylenediaminetetraacetic acid), and a suspension of Bacillus subtilis spores was used to simulate catheterization and needle use. The mixture was a 1:1 proportion of contrast and blood, inoculated so that there was a final concentration of B subtilis spores of 1.0×106 colony-forming units (CFU)/mL. The inoculated devices were cleaned using a hydrogen peroxide solution at a concentration of 1.5±0.5 percent by weight, followed by distilled water with enzymatic detergent. After drying, the devices were sterilized with hydrogen peroxide gas plasma.

The initial B subtilis spore concentration inoculated into catheters and needles varied from 2.12×104 to 2.74×107 CFU/mL. The residual load of B subtilis spores after cleaning varied from zero (no count) to a maximum of 200 CFU/device. The multistep cleaning procedure was responsible for an average 5-log10 reduction of B subtilis spores in the catheter and needle lumens.

The hydrogen peroxide and enzymatic detergent aqueous solutions were shown to be efficacious when used as part of a multistep cleaning method. The low level of microbial contamination prior to sterilization with hydrogen peroxide gas plasma assured that the intended sterility assurance level was reached.

To determine differences in the identity and quantity of microbial flora from healthcare workers (HCWs) wearing artificial nails compared with control HCWs with native nails.

Two separate studies were undertaken. In study 1, 12 HCWs who did not normally wear artificial nails wore polished artificial nails on their nondominant hand for 15 days. Identity and quantity of microflora were compared between the artificial nails and the polished native nails of the other hand. In study 2, the microbial flora of the nails of 30 HCWs who wore permanent acrylic artificial nails were compared with that of control HCWs who had native nails. In both studies, nail surfaces were swabbed and subungual debris was collected to obtain material for culture. Staphylococcus aureus, gram-negative bacilli, enterococci, and yeasts were considered to be potential pathogens. All organisms were identified and quantified.

In study 1, potential pathogens were isolated from more samples obtained from artificial nails than native nails (92% vs 62%; P<.001). Colonization of artificial nails increased over time; by day 15, 71% of cultures yielded a pathogen compared with 21% on day 1 (P=.004). A significantly greater quantity of organisms (expressed as mean log10 colony-forming units ± standard deviation) was isolated from the subungual area than the nail surface; this was noted for both artificial (5.0±1.4 vs 4.1 ±1.0; P<.001) and native nails (4.9±1.3 vs 3.7±0.8; P<.001). More organisms were found on the surface of artificial nails than native nails (P=.008), but there were no differences noted in the quantities of organisms isolated from the subungual areas. In study 2, HCWs wearing artificial nails were more likely to have a pathogen isolated than controls (87% vs 43%; P=.001). More HCWs with artificial nails had gram-negative bacilli (47% vs 17%; P=.03) and yeasts (50% vs 13%; P=.006) than control HCWs. However, the quantities of organisms isolated from HCWs wearing artificial nails and controls did not differ.

Artificial fingernails were more likely to harbor pathogens, especially gram-negative bacilli and yeasts, than native nails. The longer artificial nails were worn, the more likely that a pathogen was isolated. Current recommendations restricting artificial fingernails in certain healthcare settings appear justified.

To describe the epidemiology of nosocomial infections in combined medical-surgical (MS) intensive care units (ICUs) participating in the National Nosocomial Infection Surveillance (NNIS) System.

Analysis of surveillance data on 498,998 patients with 1,554,070 patient-days, collected between 1992 and 1998 from 205 MS ICUs following the NNIS Intensive Care Unit protocol, representing 152 participating NNIS hospitals in the United States.

Infections at three major sites represented 68% of all reported infections (nosocomial pneumonia, 31%; urinary tract infections (UTIs), 23%; and primary bloodstream infections (BSIs), 14%: 83% of episodes of nosocomial pneumonia were associated with mechanical ventilation, 97% of UTIs occurred in catheterized patients, and 87% of primary BSIs in patients with a central line. In patients with primary BSIs, coagulase-negative staphylococci (39%) were the most common pathogens reported; Staphylococcus aureus (12%) was as frequently reported as enterococci (11%). Coagulase-negative staphylococcal BSIs were increasingly reported over the 6 years, but no increase was seen in candidemia or enterococcal bacteremia. In patients with pneumonia, S aureus (17%) was the most frequently reported isolate. Of reported isolates, 59% were gram-negative bacilli. In patients with UTIs, Escherichia coli (19%) was the most frequently reported isolate. Of reported isolates, 31% were fungi. In patients with surgical-site infections, Enterococcus (17%) was the single most frequently reported pathogen. Device-associated nosocomial infection rates for BSIs, pneumonia, and UTIs did not correlate with length of ICU stay, hospital bed size, number of beds in die ICU, or season. Combined MS ICUs in major teaching hospitals had higher device-associated infection rates compared to all other hospitals with combined medical-surgical units.

Nosocomial infections in MS ICUs at the most frequent infection sites (bloodstream, urinary, and respiratory tract) almost always were associated with use of an invasive device. Device-associated infection rates were die best available comparative rates between combined MS ICUs, but the distribution of device-associated rates should be stratified by a hospital's major teaching affiliation status.

To assess the activity against three non-enveloped viruses (an adeno-, a rhino- and a rotavirus) of a gel containing 60% ethanol, using experimentally contaminated thumb- and fingerpads of 12 panelists, as per standard procedure E-1838-96 of the American Society of Testing and Materials.

Each digit received 10 μL of the test virus suspension. The inocuLum from the thumbs was eluted immediately with 990 μL of Earle's balanced salt solution (EBSS) to assess the amount of virus on each digit (0-minute control). The inoculum on the fingers was allowed to dry (20-25 minutes), and virus was eluted from two fingerpads to determine the loss in virus infectivity upon drying (baseline titer). Then the dried inoculum on randomly selected fingers was exposed to 1 mL of the test product or standard hard water (200-ppm calcium carbonate) for 20 seconds. The virus remaining was eluted with 1 mL of EBSS, titrated to determine the amounts eliminated, and compared to the baseline titer.

Each digit received at least 104 plaque-forming units of virus in 10 μL The amounts of adeno-, rhino-, and rotaviruses surviving the drying were 30%, 75%, and 42%, respectively. The product reduced the infectivity titers of the three viruses by 3 to >4 log10 when compared to a reduction of ≤ 1 log10 for the hard-water rinse.

The level of virus reduction by gel was statistically significantly higher than that seen with the water control. Evidence for such activity against non-enveloped viruses supports further investigation of the benefits of this product.

To determine the prevalence and determinants of fecal carriage of vancomycin-resistant enterococci (VRE) in intensive care unit (ICU), hematology-oncology, and hemodialysis patients in The Netherlands.

Descriptive, multicenter study, with yearly 1-week point-prevalence assessments between 1995 and 1998.

All patients hospitalized on the testing days in ICUs and hematology-oncology wards in nine hospitals in The Netherlands were included.

Rectal swabs obtained from 1,112 patients were screened for enterococci in a selective broth and subcultured on selective media with and without 6 mg/L vancomycin. Resistance genotypes were determined by polymerase chain reaction. Further characterization of VRE strains was done by pulsed-field gel electrophoresis (PFGE). We studied possible determinants of VRE colonization with a logistic regression analysis model. Determinants analyzed included gender, age, and log-transformed length of prior hospital stay.

The results showed that 614 (55%) of 1,112 patients were colonized with vancomycin-sensitive enterococci, and 15 (1.4%) of 1,112 carried VRE. No increase in VRE colonization was observed from 1995 to 1998. Eleven strains were identified as Enterococcus faecium and four as Enterococcus faecalis. All E faecium and one E faecalis carried the vanA gene; the other E faecalis strains harbored the vanB gene. PFGE revealed that three vanB VRE isolated from patients hospitalized in one single ICU were related, suggesting nosocomial transmission. Though higher age seemed associated with VRE colonization, exclusion of patients with the nosocomial strain from the regression analysis decreased this relation to nonsignificant. Duration of hospital stay was not associated with VRE colonization.

VRE colonization in Dutch hospitals is an infrequent phenomenon. Although nosocomial spread occurs, most observed cases were unrelated, which suggests the possibility of VRE acquisition from outside the hospital. Prolonged hospital stay, age, and gender proved unrelated to VRE colonization.