To assess possible transmission modes of, and risk factors for, gastroenteritis associated with Norwalk-like viruses (NLVs) in a geriatric long-term-care facility.

During a prolonged outbreak of acute gastroenteritis, epidemiological data on illness among residents and employees were collected in conjunction with stool, vomitus, and environmental specimens for viral testing. NLVs were identified by electron microscopy in stool and vomitus specimens, and further characterized by reverse-transcriptase polymerase chain reaction and nucleotide sequencing. Potential risk factors were examined through medical-record review, personal interview, and a self-administered questionnaire sent to all employees.

During the outbreak period, 52 (57%) of 91 residents and 34 (35%) of 90 employees developed acute gastroenteritis. Four case-residents were hospitalized; three residents died at the facility shortly after onset of illness. A point source was not identified; no association between food or water consumption and gastroenteritis was identified. A single NLV strain genetically related to Toronto virus was the only pathogen identified. Residents were at significantly higher risk of gastroenteritis if they were physically debilitated (relative risk [RR], 3.5; 95% confidence interval [CI95], 1.0-12.9), as were employees exposed to residents with acute gastroenteritis (RR, 2.6; CI95, 1.1-6.5) or ill household members (RR, 2.3; CI95, 1.4-3.6). Adherence to infection control measures among the nursing staff may have reduced the risk of gastroenteritis, but the reduction did not reach statistical significance.

In the absence of evidence for food-borne or waterborne transmission, NLVs likely spread among residents and employees of a long-term-care facility through person-to-person or airborne droplet transmission. Rapid notification of local health officials, collection of clinical specimens, and institution of infection control measures are necessary if viral gastroenteritis transmission is to be limited in institutional settings

To describe the investigation and control of transmission of vancomycin-resistant enterococci (VRE) in a residential long-term-care (LTC) setting.

A strain of vancomycin-resistant Enterococcus faecium not previously isolated in Ontario colonized five residents of a 254-bed LTC facility in Toronto. The index case was identified when VRE was isolated from a urine culture taken after admission to a local hospital. Screening of rectal swabs from all 235 residents identified four others who were colonized with the same strain of E faecium.

Colonized residents were cohorted. VRE precautions were established as follows: gown and gloves for resident contact, restriction of contact between colonized and noncolonized residents, no sharing of personal equipment, and daily double-cleaning of residents' rooms and wheelchairs.

Two colonized residents died of causes unrelated to VRE. Although bacitracin therapy (75,000 units four times a day X 14 days) failed to eradicate carriage in two of three surviving residents, both cleared their carriage within 7 weeks. Repeat rectal swabs from 224 residents (91%) 2 months after isolation precautions were discontinued and from 125 residents (51%) 9 months later identified no new cases. Total cost of investigation and control was $12,061 (Canadian).

VRE may be transmitted in LTC facilities, and colonized LTC residents could become important VRE reservoirs. Control of VRE transmission in LTC facilities can be achieved even with limited resources.

To identify risk factors for vancomycin resistance and mortality in enterococcal bacteremia.

Historical cohort study.

A large academic medical center with a high prevalence of vancomycin-resistant enterococci (VRE).

Two hundred sixty patients with enterococcal bacteremia, of whom 72 (28%) had VRE.

Independent risk factors for infection with VRE were the mean number of antibiotic days (P<.001), renal insufficiency (P<.001), mean days of vancomycin use (P=.005), and neutropenia (P=.013). A trend toward a significant association between metronidazole use and VRE also was noted (P=.068). Mortality was attributable to the bacteremia in 96 patients (37%). Severity of illness (P<.001) and age (P=.020) were independent risk factors for mortality. Vancomycin resistance was not, however, an independent predictor of mortality.

These results suggest that restrictions on antibiotic use, particularly in patients with renal insufficiency and neutropenia, may help to combat the rising incidence of VRE. Although patients with VRE bacteremia demonstrated higher mortality rates than patients with infection due to susceptible isolates, vancomycin resistance was not an independent predictor of mortality in these patients and likely serves more as a marker of underlying severity of illness.

To assess the mycobactericidal efficacy of an agent relatively new to disinfection, ortho-phthalaldehyde (OPA) and to compare the resistances of three Mycobacterium species. Mycobacterium bovis (strain BCG) was compared with Mycobacterium chelonae and Mycobacterium terrae to investigate the feasibility of using either of the latter two species in tuberculocidal testing. M chelonae (a rapid grower) and M terrae (an intermediate grower) both grow faster and are less virulent than M bovis (a slow grower).

The quantitative suspension protocol specified by the Environmental Protection Agency (EPA), the Tuberculocidal Activity Test Method (EPA test), was used throughout this study. Standard suspensions of all three species were prepared in a similar manner. Two suspensions of M bovis, created in different laboratories, were used. These were tested against two concentrations of alkaline glutaraldehyde to provide reference data. Two concentrations of OPA were evaluated against all mycobacterial test suspensions. Four replicates of each organism-disinfectant combination were performed.

Results were assessed by analysis of variance. M terrae was significantly more resistant to 0.05% OPA than either M bovis or M chelonae. At 0.21% OPA, M terrae was slightly more susceptible than one test suspension of M bovis, but not significantly different from the other. M chelonae was significantly less resistant than the other species at both OPA concentrations. At their respective minimum effective concentration, OPA achieved a 6-log10 reduction of M bovis in nearly one sixth the time required by glutaraldehyde (5.5 minutes vs 32 minutes).

These data, along with other recent studies, lend support to the idea that M terrae may be a suitable test organism for use in the tuberculocidal efficacy testing of disinfectants. They also confirm the relatively rapid tuberculocidal activity of OPA.

To measure the frequency of occupational exposures reported by dentists in Canada and to identify factors associated with occupational exposure.

A national mailed survey of a stratified random sample of 6,444 dentists with three follow-up attempts. Weighted data were analyzed using t tests, analysis of variance, and multiple logistic regression.

The response rate was approximately 66%. Occupational exposures, percutaneous injuries, and mucous membrane exposures in the last year were reported by 67%, 62%, and 29% of respondents, respectively. Fewer than 1% reported exposure to human immunodeficiency virus or hepatitis B virus (HBV). Respondents reported means of 1.5 mucous membrane and 3.0 percutaneous exposures per year. HBV immunization was reported by 91% of dentists, but of these 28% reported no post-immunization serology. Other reports of suboptimal compliance included use of a postexposure protocol by only 41% and HBV vaccination of all assistants or of hygienists by 74% and 77% of respondents, respectively. Factors associated with percutaneous exposure included non-use of postexposure protocol or puncture-proof containers for sharps disposal, treating ⩾20 patients per day, and male gender. Risk factors for mucous membrane exposure included non-use of eye protection or masks.

This study provides evidence of the protective effect of puncture-proof containers, eye protection, and masks and raises concerns related to HBV post-immunization serology and postexposure protocols. To reduce risk of infection, educational interventions are required to improve compliance with Universal Precautions, with emphasis on comprehensive HBV immunization and post-immunization serology, the use of barriers, puncture-proof containers for sharps disposal, and postexposure protocols.

To determine trends in compliance with the guidelines for preventing the transmission of Mycobacterium tuberculosis in healthcare facilities among New Jersey hospitals from 1989 through 1996.

A voluntary questionnaire was sent to all 96 New Jersey hospitals in 1992. The 53 that responded were resurveyed in 1996.

Of the 96 hospitals surveyed in 1992, 53 (55%) returned a completed questionnaire; 33 (64%) were community, nonteaching hospitals. In 1991, patients with tuberculosis (TB) were admitted at 38 (72%) of 53 hospitals, and from 1989 through 1991, patients with multidrug-resistant (MDR) TB were admitted at 15 (29%) of 52 hospitals. Twenty-nine (57%) of 51 reported having rooms meeting the Centers for Disease Control and Prevention (CDC) criteria for acid-fast bacilli (AFB) isolation. A nonfltted surgical mask was used as a respiratory protective device by healthcare workers (HCWs) at 28 (55%) of 51 hospitals. Attending physicians were included in tuberculin skin-testing (TST) programs at 5 (11%) of 45 hospitals. In the 1996 resurvey, 48 (94%) of 53 surveyed hospitals returned a completed questionnaire; 34 (81%) of 42 had TB patient admissions, and 4 (9%) of 43 had MDR TB patient admissions in 1996. Forty-five (96%) of 47 reported having rooms that met CDC criteria for AFB isolation. N95 respiratory devices were used by HCWs at 45 (94%) of 48 hospitals. Attending physicians were included in the TST programs at 22 (54%) of 41 hospitals.

New Jersey hospitals have made improvements in availability of AFB isolation rooms, use of proper respiratory protective devices, and expansion of TST programs for HCWs from 1989 through 1996.