CTP-based estimated ischemic core: A comparative multicenter study between Olea and RAPID software.

BACKGROUND AND PURPOSE: CTP is increasingly used to assess eligibility for endovascular therapy (EVT) in patients with large vessel occlusions (LVO). There remain variability and inconsistencies between software packages for estimation of ischemic core. We aimed to use heterogenous data from four stroke centers to perform a comparative analysis for CTP-estimated ischemic core between RAPID (iSchemaView) and Olea (Olea Medical). METHODS: In this retrospective multicenter study, patients with anterior circulation LVO who underwent pretreatment CTP, successful EVT (defined TICI ≥ 2b), and follow-up MRI included. Automated CTP analysis was performed using Olea platform [rCBF < 25% and differential time-to-peak (dTTP)>5s] and RAPID (rCBF < 30%). The CTP estimated core volumes were compared against the final infarct volume (FIV) on post treatment MRI-DWI. RESULTS: A total of 151 patients included. The CTP-estimated ischemic core volumes (mean ± SD) were 18.7 ± 18.9 mL on Olea and 10.5 ± 17.9 mL on RAPID significantly different (p < 0.01). The correlation between CTP estimated core and MRI final infarct volume was r = 0.38, p < 0.01 for RAPID and r = 0.39, p < 0.01 for Olea. Both software platforms demonstrated a strong correlation with each other (r = 0.864, p < 0.001). Both software overestimated the ischemic core volume above 70 mL in 4 patients (2.6%). CONCLUSIONS: Substantial variation between Olea and RAPID CTP-estimated core volumes exists, though rates of overcalling of large core were low and identical. Both showed comparable core volume correlation to MRI infarct volume.

Overestimation of ischemic core on baseline MRI in acute stroke.

BACKGROUND AND PURPOSE: In patients with acute ischemic stroke (AIS), overestimation of ischemic core on MRI-DWI has been described primarily in regions with milder reduced diffusion. We aimed to assess the possibility of ischemic core overestimation on pretreatment MRI despite using more restricted reduced diffusion (apparent diffusion coefficient (ADC) ≤620 × 10-6 mm2/s) in AIS patients with successful reperfusion. MATERIALS AND METHODS: In this retrospective single institutional study, AIS patients who had pretreatment MRI underwent successful reperfusion and had follow-up MRI to determine the final infarct volume were reviewed. Pretreatment ischemic core and final infarction volumes were calculated. Ghost core was defined as overestimation of final infarct volume by baseline MRI of >10 mL. Baseline clinical, demographic, and treatment-related factors in this cohort were reviewed. RESULTS: A total of 6/156 (3.8%) patients had overestimated ischemic core volume on baseline MRI, with mean overestimation of 65.6 mL. Three out of six patients had pretreatment ischemic core estimation of >70 mL, while the final infarct volume was <70 mL. All six patients had last known well-to-imaging <120 min, median (IQR): 65 (53-81) minutes. CONCLUSIONS: Overestimation of ischemic core, known as ghost core, is rare using severe ADC threshold (≤620 × 10-6 mm2/s), but it does occur in nearly 1 of every 25 patients, confined to hyperacute patients imaged within 120 min of symptom onset. Awareness of this phenomenon carries implications for treatment and trial enrollment.

Automated Assessment of the DWI-FLAIR Mismatch in Patients with Acute Ischemic Stroke: Added Value to Routine Clinical Practice.

BACKGROUND AND PURPOSE: The DWI-FLAIR mismatch is used to determine thrombolytic eligibility in patients with acute ischemic stroke when the time since stroke onset is unknown. Commercial software packages have been developed for automated DWI-FLAIR classification. We aimed to use e-Stroke software for automated classification of the DWI-FLAIR mismatch in a cohort of patients with acute ischemic stroke and in a comparative analysis with 2 expert neuroradiologists. MATERIALS AND METHODS: In this retrospective study, patients with acute ischemic stroke who had MR imaging and known time since stroke onset were included. The DWI-FLAIR mismatch was evaluated by 2 neuroradiologists blinded to the time since stroke onset and automatically by the e-Stroke software. After 4 weeks, the neuroradiologists re-evaluated the MR images, this time equipped with automated predicted e-Stroke results as a computer-assisted tool. Diagnostic performances of e-Stroke software and the neuroradiologists were evaluated for prediction of DWI-FLAIR mismatch status. RESULTS: A total of 157 patients met the inclusion criteria. A total of 82 patients (52%) had a time since stroke onset of ≤4.5 hours. By means of consensus reads, 81 patients (51.5%) had a DWI-FLAIR mismatch. The diagnostic accuracy (area under the curve/sensitivity/specificity) of e-Stroke software for the determination of the DWI-FLAIR mismatch was 0.72/90.0/53.9. The diagnostic accuracy (area under the curve/sensitivity/specificity) for neuroradiologists 1 and 2 was 0.76/69.1/84.2 and 0.82/91.4/73.7, respectively; both significantly (P < .05) improved to 0.83/79.0/86.8 and 0.89/92.6/85.5, respectively, following the use of e-Stroke predictions as a computer-assisted tool. The interrater agreement (κ) for determination of DWI-FLAIR status was improved from 0.49 to 0.57 following the use of the computer-assisted tool. CONCLUSIONS: This automated quantitative approach for DWI-FLAIR mismatch provides results comparable with those of human experts and can improve the diagnostic accuracies of expert neuroradiologists in the determination of DWI-FLAIR status.

Spontaneous high-grade glial intramedullary tumor of the spine in a rhesus macaque (Macaca mulatta).

BACKGROUND: A 4-year-old rhesus macaque presented with acute, progressive paresis of the extremities. METHODS: A complete blood count, serum biochemical analysis, neurologic exam and necropsy were performed. RESULTS: The clinical, histopathological, and immunohistochemical findings confirmed a high-grade intramedullary glial tumor of the spinal cord that was most consistent with an ependymoma. CONCLUSIONS: We describe a case of a naturally occurring spontaneous spinal cord neoplasia in a non-human primate.

Spontaneous and carcinogen-induced tumorigenesis in p53-deficient mice.

Using gene targeting techniques, mice that have been generated with two germ-line p53 null alleles (homozygotes) develop normally but are highly susceptible to early onset spontaneous tumours. Here, we show that mice with a single null p53 allele (heterozygotes) produced in the same way are also susceptible to spontaneous tumours, but with a delayed onset compared to homozygotes. The most frequent tumour type in homozygotes was malignant lymphoma; in heterozygotes, osteosarcomas and soft tissue sarcomas predominated. Heterozygous mice treated with a liver carcinogen, dimethylnitrosamine, showed a decreased survival time in comparison to treated wild type mice, suggesting that the p53-deficient mice may be useful for some in vivo carcinogenesis assays.

Risk factors associated with veterinary attrition from clinical practice: a descriptive study.

A sustainable workforce is important for the veterinary profession to meet the demands of society. To maintain a sustainable workforce, it has been recommended to retain veterinary clinicians. However, there seems to be an increasing issue with retention of veterinarians in clinical practice. In the following study, the researchers sought to understand the associations between demographic and work-related factors and attrition of veterinarians from clinical practice. Responses to an online cross-sectional survey of 881 current and former Australian veterinary clinicians were analysed. A logistic regression model was used to identify and describe associations between attrition from veterinary clinical practice and salary, working hours, role in practice, years of experience, field of work, interaction with regulatory authorities, region of work and on-call duties. Lower salary, longer working hours, having on-call duties and having worked in both rural and metropolitan regions were found to significantly (P < 0.05) increase the likelihood of leaving clinical practice. The results may inform intervention strategies to assist the industry to retain veterinarians in clinical practice.

Spontaneous skin ulceration and defective T cell function in CD18 null mice.

A null mutation was prepared in the mouse for CD18, the beta2 subunit of leukocyte integrins. Homozygous CD18 null mice develop chronic dermatitis with extensive facial and submandibular erosions. The phenotype includes elevated neutrophil counts, increased immunoglobulin levels, lymphadenopathy, splenomegaly, and abundant plasma cells in skin, lymph nodes, gut, and kidney. Very few neutrophils were found in spontaneously occurring skin lesions or with an induced toxic dermatitis. Intravital microscopy in CD18 null mice revealed a lack of firm neutrophil attachment to venules in the cremaster muscle in response to N-formyl- methionyl-leucyl-phenylalanine. A severe defect in T cell proliferation was found in the CD18 null mice when T cell receptors were stimulated either by staphylococcal enterotoxin A or by major histocompatibility complex alloantigens demonstrating a greater role of CD11/CD18 integrins in T cell responses than previously documented. The null mice are useful for delineating the functions of CD18 in vivo.

Hospital-acquired invasive group a streptococcal infections in Ontario, Canada, 1992-2000.

BACKGROUND: A significant proportion of invasive group A streptococcal infections are hospital acquired. No large, prospective studies have characterized this subgroup of cases and evaluated the risk of transmission in hospitals. METHODS: We conducted prospective, population-based surveillance of invasive group A streptococcal infections in Ontario, Canada, from 1992 to 2000. Epidemiologic and microbiologic investigations were conducted to identify cross-transmission. RESULTS: We identified 291 hospital-acquired cases (12.4%) among 2351 cases of invasive group A streptococcal disease. Hospital-acquired invasive group A streptococcal infections are heterogeneous, including surgical site (96 cases), postpartum (86 cases), and nonsurgical, nonobstetrical infections (109 cases). Surgical site infections affected 1 of 100,000 surgical procedures and involved all organ systems. Postpartum infections occurred at a rate of 0.7 cases per 10,000 live births and exhibited an excellent prognosis. Nonsurgical, nonobstetrical infections encompassed a broad range of infectious syndromes (case-fatality rate, 37%). Nine percent of cases were associated with in-hospital transmission. Transmission occurred from 3 of 142 patients with community-acquired cases of necrotizing fasciitis requiring intensive care unit (ICU) admission, compared with 1 of 367 patients with community-acquired cases without necrotizing fasciitis admitted to the ICU and 1 of 1551 patients with other cases (P<.001). Fifteen outbreaks were identified; 9 (60%) involved only 2 cases. Hospital staff were infected in 1 of 15 outbreaks, but colonized staff were identified in 6 (60%) of 10 investigations in which staff were screened. CONCLUSIONS: Presentation of hospital-associated invasive group A streptococcal infections is diverse. Cross-transmission is common; illness occurs in patients but rarely in staff. Isolation of new cases of necrotizing fasciitis and intervention after a single nosocomial case may also prevent transmission.

Beta-cell mass dynamics in Zucker diabetic fatty rats. Rosiglitazone prevents the rise in net cell death.

The evolution of diabetes in the male leptin receptor-deficient (fa/fa) Zucker diabetic fatty (ZDF) rat is associated with disruption of normal islet architecture, beta-cell degranulation, and increased beta-cell death. It is unknown whether these changes precede or develop as a result of the increasing plasma glucose, or whether the increased beta-cell death can be prevented. Early intervention with thiazolidinediones prevents disruption of the islet architecture. To determine the specific effects of rosiglitazone (RSG) on beta-cell mass dynamics, male fa/fa (obese) and +/fa or +/+ (lean) rats age 6 weeks were fed either chow (control group [CN]) or chow mixed with rosiglitazone (RSG group) at a dosage of 10 micromol. kg(-1) body wt.day(-1). Rats were killed after 0, 2, 4, 6, or 10 weeks of treatment (at age 6, 8, 10, 12, or 16 weeks). Plasma glucose increased from 8.9 +/- 0.4 mmol/l at 0 weeks to 34.2 +/- 1.8 mmol/l (P = 0.0001) at 6 weeks of treatment in obese CN rats and fell from 8.0 +/- 0.3 to 6.3 +/- 0.4 mmol/l in obese RSG rats (P = 0.02). beta-cell mass fell by 51% from 2 to 6 weeks of treatment (ages 8-12 weeks) in obese CN rats (6.9 +/- 0.9 to 3.4 +/- 0.5 mg; P < 0.05), whereas beta-cell mass was unchanged in obese RSG rats. At 10 weeks of treatment (age 16 weeks), beta-cell mass in obese CN rats was only 56% of that of obese RSG rats (4.4 +/- 0.4 vs. 7.8 +/- 0.3 mg, respectively; P = 0.0001). The beta-cell replication rate fell from a baseline value of 0.95 +/- 0.12% in lean rats and 0.94 +/- 0.07% in obese rats (at 0 weeks) to approximately 0.3-0.5% in all groups by 6 weeks of treatment (age 12 weeks). After 10 weeks of treatment, beta-cell replication was higher in obese RSG rats than in CN rats (0.59 +/- 0.14 vs. 0.28 +/- 0.05%, respectively; P < 0.02). Application of our mass balance model of beta-cell turnover indicated that net beta-cell death was fivefold higher in obese CN rats as compared with RSG rats after 6 weeks of treatment (age 12 weeks). The increase in beta-cell death in obese CN rats during the 6-week observation period was well correlated with the increase in plasma glucose (r2 = 0.90, P < 0.0001). These results suggest that the development of hyperglycemia in ZDF rats is concomitant with increasing net beta-cell death. beta-cell proliferation compensates for the increased beta-cell loss at a time when plasma glucose is moderately elevated, but compensation ultimately fails and the plasma glucose levels increase beyond approximately 20 mmol/l. Treatment with rosiglitazone, previously shown to reduce insulin resistance, prevents the loss of beta-cell mass in obese ZDF rats by maintaining beta-cell proliferation and preventing increased net beta-cell death.

Quantification of DNaseI-sensitivity by real-time PCR: quantitative analysis of DNaseI-hypersensitivity of the mouse beta-globin LCR.

We employ real-time PCR to allow us to quantify the sensitivity of chromatin to digestion by DNaseI. This approach has three clear advantages over the more conventional use of the Southern hybridization assay: the accuracy of quantification is improved; the resolution of the assay is enhanced, by designing primers to amplify small amplicons it is possible to analyze sequences both co-incident and proximal to sites of DNaseI-hypersensitivity; less material is needed, as little as 5 ng of treated genomic DNA. We applied this method in an analysis of the chromatin structure of the previously described mouse beta-globin locus control region (LCR) using fetal liver cells. The four hypersensitive sites of the canonical mouse LCR, HS1 to HS4, are shown to have kinetics of digestion consistent with these sequences being nucleosome-free in vivo. A different pattern was seen for HS6, a recently described "weak" hypersensitive site. The site was also rapidly lost but more of the sites proved resistant, we interpreted this to show that this hypersensitive was only forming in a portion of the erythroid cells. This finding implies that in vivo the LCR is structurally heterogeneous. Sequences proximal to the hypersensitive sites show a third pattern of intermediate sensitivity, consistent with the chromatin being unfolded but the sites still bound by a continual nucleosomal array. Our results demonstrate that this method has the potential to achieve accurate and detailed mapping of chromatin structure from small amounts of tissue samples.

The 5'HS4 core element of the human beta-globin locus control region is required for high-level globin gene expression in definitive but not in primitive erythropoiesis.

To assess the contribution of DNase I-hypersensitive site 4 (HS4) of the beta-globin locus control region (LCR) to overall LCR function we deleted a 280 bp fragment encompassing the core element of 5'HS4 from a 248 kb beta-globin locus yeast artificial chromosome (beta-YAC) and analyzed globin gene expression during development in beta-YAC transgenic mice. Four transgenic lines were established; each contained at least one intact copy of the beta-globin locus. The deletion of the 5'HS4 core element had no effect on globin gene expression during embryonic erythropoiesis. In contrast, deletion of the 5'HS4 core resulted in a significant decrease of gamma and beta-globin gene expression during definitive erythropoiesis in the fetal liver and a decrease of beta-globin gene expression in adult blood. We conclude that the core element of 5'HS4 is required for globin gene expression only in definitive erythropoiesis. Absence of the core element of HS4 may limit the ability of the LCR to provide an open chromatin domain and/or enhance gamma and beta-globin gene expression in the adult erythroid cells.

Inhibition of retinoid signaling in transgenic mice alters lipid processing and disrupts epidermal barrier function.

To explore the role of retinoids in epidermal development, we recently targeted expression of a dominant-negative, retinoic acid receptor mutant (RAR alpha403) in the epidermis of transgenic mice and observed an unexpected loss of barrier function. In this paper, we demonstrate that transgenic mice expressing the RAR alpha403 transgene show attenuated responsiveness to topical application of all-trans retinoic acid, in agreement with our previous in vitro data. We also show that the vitamin D3 receptor is unaffected in its ability to transactivate in the presence of the dominant-negative RAR alpha403 transgene, indicating that the RAR alpha403 is unlikely to be functioning through a global sequestration of retinoid X receptors. Additionally, we show that the disruption of epidermal barrier function results in a dramatic 4 C drop in mean body surface temperature, probably accounting for the extremely high incidence of neonatal mortality in severely phenotypic pups. Some severely affected pups do survive and show a pronounced hyperkeratosis at postpartum day 4, consistent with previously documented effects of vitamin A deficiency. Biochemical analysis of the severely phenotypic neonates indicates elevated phospholipids and glycosylceramides in the stratum comeum, which results from altered lipid processing. Taken together with previous studies, these data provide strong evidence linking the retinoid-signaling pathway with modulation of lipid processing required for formation of epidermal barrier function.

Risk factors for pneumonia and other lower respiratory tract infections in elderly residents of long-term care facilities.

BACKGROUND: Little is known about the risk factors, outcome, and impact of pneumonia and other lower respiratory tract infections (LRTIs) in residents of long-term care facilities. OBJECTIVE: To determine the risk factors and the effect of these infections on functional status and clinical course. METHODS: Active surveillance for these infections was conducted for 475 residents in 5 nursing homes from July 1, 1993, through June 30, 1996. Information regarding potential risk factors for these infections, functional status, transfers to hospital, and death was also obtained. RESULTS: Two hundred seventy-two episodes of pneumonia and other LRTIs occurred in 170 residents during 228 757 days of surveillance for an incidence of 1.2 episodes per 1000 resident-days. Multivariable analysis revealed that older age (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1-2.6 per 10-year interval; P = .01), male sex (OR, 1.9; 95% CI, 1.1-3.5; P = .03), swallowing difficulty (OR, 2.0; 95% CI, 1.2-3.3; P = .01), and the inability to take oral medications (OR, 8.3; 95% CI, 1.4-50.3; P = .02) were significant risk factors for pneumonia; receipt of influenza vaccine (OR, 0.4; 95% CI, 0.3-0.5; P = .01) was protective. Age (OR, 1.6 [95% CI, 1.0-2.5] per 10-year interval; P = .05) and immobility (OR, 2.6; 95% CI, 1.8-3.8; P = .01) were significant risk factors for other LRTIs, and influenza vaccination was protective (OR, 0.3; 95% CI, 0.2-0.4; P = .01). Residents with pneumonia (OR, 0.7; 95% CI, 0.3-1.4; P = .31) or with other LRTIs (OR, 0.5; 95% CI, 0.2-1.1; P = .43) were no more likely to have a deterioration in functional status than individuals in whom infection did not develop. CONCLUSIONS: Swallowing difficulty and lack of influenza vaccination are important, modifiable risks for pneumonia and other LRTIs in elderly residents of long-term care facilities. Our findings challenge the commonly held belief that pneumonia leads to long-term decline in functional status in this population.

A pilot mixed methods investigation of the use of Oswestry standing frames in the homes of nine people with severe multiple sclerosis.

PURPOSE: People with multiple sclerosis (MS) commonly experience muscle weakness which limits their ability to stand. Supported standing may minimise the secondary complications of prolonged sitting but evidence for this is scarce. This study investigated the effects of regular standing in an Oswestry frame on some secondary complications of immobility and explored the lived experience of standing. METHODS: Nine people with MS participated in a mixed-methods study over 48 weeks. Single-case experiments were used. Outcomes included: Amended Motor Club Assessment, Canadian Occupational Performance Measure, Penn Spasm Scale, bowel frequency and a numerical pain-scale. The qualitative strand used a case-study approach with a phenomenological perspective. RESULTS: Significant improvements (p < 0.05) were demonstrated for individuals in strength, ADL and spasms but not in bowel frequency or pain. Subjective improvements occurred in continence, clonus and fall-rate. Being upright or strengthened by standing enabled participants to re-engage with activities and re-establish themselves within relationship roles. This engendered a sense of achievement and increased optimism. CONCLUSION: This study provides preliminary evidence of the effectiveness of regular frame-standing in improving strength, function, spasms, continence and fall-rate in people with severe MS. Standing reinstated a sense of belonging and optimism by restoring important life-roles and feelings of normality as participants regained previously valued activities. Implications for Rehabilitation Regular standing in an Oswestry frame may improve functional ability in people with severe MS. Regular frame standing may have a positive psychological effect on people with severe MS. Self-management of a standing regime may be feasible.

The bistratenes: new cytotoxic marine macrolides which induce some properties indicative of differentiation in HL-60 cells.

The biological effects of cytotoxic macrolide polyethers, the bistratenes, isolated from the ascidian Lissoclinum bistratum, have been examined. Bistratene A was toxic to HL-60 human promyelocytic leukemia cells with an IC50 value of 424 nM. At lower concentrations (10-100 nM), bistratene A induced the incomplete differentiation of these cells along the monocyte/macrophage pathway. These effects were not due to inhibition of DNA synthesis. Bistratene B had similar effects to bistratene A. At micromolar concentrations these compounds enhance the phospholipid-dependent activity of type II protein kinase C from bovine spleen. The bistratenes provide new probes for studying the molecular mechanisms governing cell growth and differentiation.

A comparison of model-building strategies for lower respiratory tract infection in long-term care.

Five strategies for creating predictive models of lower respiratory tract infection in residents of long-term care facilities were compared. A linear judgment model was derived by administering clinical vignettes to physicians who indicated the risk of infection based on the presence or absence of five predictor variables. A model based on physician consensus was created using the same variables. Three models based on empirical data (logistic regression, proportional hazards, and recursive partitioning) were created from a "derivation" sample of data from a cohort study of lower respiratory tract infections in nursing homes using the five predictor variables. All models were applied to a validation set and compared using receiver operating characteristic (ROC) curves. The data-derived and consensus models showed the highest discriminative ability while the linear judgment model showed inferior performance.

Influenza and pneumococcal vaccination and tuberculin skin testing programs in long-term care facilities: where do we stand?

OBJECTIVE: 1) To compare policies and procedures for distribution of influenza and pneumococcal vaccines to long-term care facilities for the elderly in Canada, 2) to determine vaccination rates of residents and staff, and 3) to describe vaccination and tuberculin skin testing programs in these facilities. DESIGN: A cross-sectional survey consisting of telephone interviews and a mailed questionnaire was conducted in the spring of 1991. Telephone interviews were conducted with provincial/territorial epidemiologists. The questionnaire was sent to all (N = 1.520) Canadian long-term care facilities for the elderly with > or = 25 beds. RESULTS: There were 1,270 responding facilities (84%). The mean overall influenza vaccination rate for residents was 78.5%. The mean vaccination rate was higher in those provinces in which the vaccine was paid for by the government (79% versus 71%; P = 0.002). Only 19% of facilities reported staff vaccination rates > 25%; rates again were higher in those provinces in which vaccine for staff was provided by the government. Pneumococcal vaccine was offered to residents in 12% of the facilities. The proportions of facilities with > 10% and > 75% of residents vaccinated were significantly higher in the provinces where the pneumococcal vaccine was recommended and paid for as compared with those where it was not (P < 0.001 for both). Tuberculin skin testing programs for residents existed in 360 long-term care facilities (28%) across the country. CONCLUSION: In 1990, the number of residents living in Canadian long-term care facilities who were vaccinated against influenza and Streptococcus pneumoniae was suboptimal. Staff influenza vaccination rates were very low across the country. Most facilities did not have a baseline tuberculin skin test status for their residents. Vaccination rates are higher in jurisdictions in which governments provide the vaccine without charge.

Influenza vaccination in long-term-care facilities: structuring programs for success.

OBJECTIVES: To determine which influenza vaccination program characteristics were associated with high resident vaccination rates in Canadian long-term-care facilities (LTCFs). DESIGN: A cross-sectional survey consisting of a mailed questionnaire conducted in spring 1991. PARTICIPANTS: All 1,520 Canadian LTCFs for the elderly with at least 25 beds. RESULTS: 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. CONCLUSION: 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.

Tuberculosis surveillance practices in long-term care institutions.

OBJECTIVES: To identify the tuberculosis (TB) skin-testing practices of long-term care facilities for the elderly in Toronto, Ontario. DESIGN: A telephone survey using a 25-item questionnaire. SETTING: Twenty-nine nursing homes (NHs) and 26 Homes for the Aged (HFAs) in metropolitan Toronto. RESULTS: Thirty-one percent of facilities (17 of 55) had no formal tuberculin skin-testing program, including 52% of NHs (15 of 29) versus 8% of HFAs (2 of 26; P = 0.001). Ninety-two percent of HFAs (24 of 26), compared with 45% of NHs (13 of 29), obtained preadmission or admission skin-test status of residents (P = 0.0005). Annual testing was performed at 46% of HFAs (12 of 26) and 27% of NHs (8 of 29; P = 0.28). Of facilities that carried out any skin testing, 64% of HFAs (16 of 25) versus 32% of NHs (6 of 19) measured induration to establish test positivity (P = 0.068). Fifty-two percent of HFAs (13 of 25), compared with 21% of NHs (4 of 19), recorded the actual size of induration in the patient record (P = 0.085). Only 28% of HFAs (7 of 25) and 21% of NHs (4 of 19) correctly defined a positive tuberculin skin test. CONCLUSIONS: TB surveillance practices in long-term care institutions in Toronto are inadequate and often yield results that do not predict the risk of infection and cannot be used to investigate outbreaks. Tuberculin skin-testing practices were better at HFAs, which are subject to provincial legislation regarding TB surveillance, than at NHs, which are not subject to this legislation. Staff at HFAs and NHs require education regarding tuberculin skin-testing policies and procedures.