Paediatric tuberculosis among the foreign-born: utility of the Canadian TB immigration medical surveillance programme.

BACKGROUND: There are few data on the utility of screening paediatric immigrants for tuberculosis (TB) in low TB burden countries. OBJECTIVE: To evaluate the utility of the Canadian immigration medical examination and TB Medical Surveillance (TBMS) for detecting paediatric TB disease. DESIGN: A 10-year population-based retrospective cohort study of foreign-born children (ages 0-10 years) and adolescents (ages 11-17 years) immigrating to Ontario, Canada, using linked immigration and public health databases. RESULTS: Among 232 169 individuals (median follow-up of 5.7 years), active TB was diagnosed at or after immigration in 125 cases (20 children and 105 adolescents), at an overall rate of 54/100 000 (14/100 000 children, 116/100 000 adolescents). All cases originated from 34 countries. Active TB was diagnosed in 0/419 children and 10/418 adolescents referred for medical surveillance, representing only 8.0% of all cases. TBMS referrals were correlated with a previous diagnosis of TB (κ = 0.8) and were driven by country of origin (e.g., hazard ratio 31.2 for the Philippines). Rates of pre-immigration TB diagnosis varied considerably among high TB burden countries. CONCLUSIONS: The current Canadian system detects little TB disease, and reveals very different rates of pre-immigration paediatric TB diagnosis in different high TB burden countries. These data provide a basis for improving TB screening strategies for immigrants to low TB burden countries.

Available from Available from A cluster of tuberculosis cases linked to smoking: An under-recognized challenge for tuberculosis elimination.

BACKGROUND: Smoking is known to increase the risk of tuberculosis (TB) infection, active TB disease, relapse following treatment and death from TB, but its significance is often underappreciated as a potentially reversible risk factor in public health and clinical TB practice in Canada. OBJECTIVE: To review the current evidence on smoking and the risk of TB, describe a cluster investigation of local TB transmission related to smoking in Toronto, Ontario, and discuss the practical implications of smoking for TB elimination in Canada. INVESTIGATION AND PUBLIC HEALTH RESPONSE: Three TB cases were identified at the same workplace over a two year period. All three strains matched on genotyping. Extensive interviews with the cases and workplace / building managers confirmed that the three cases did not work or socialize together. The only epidemiologic link identified was that all three were regular smokers and used the same location outside the building for smoke breaks. A building ventilation assessment confirmed that unfiltered air was not recirculated between floors. Based on the epidemiological and laboratory evidence, we determined that transmission likely occurred at the partly-sheltered smoking area outside of the worksite. We established and advertised an active case-finding clinic on-site to all workers who frequented smoking areas near the building. Of 60 individuals screened with tuberculin skin testing (TST), no additional active TB cases were identified. One Canadianborn person was found to be TST positive. We also offered TB education sessions to all staff in the building, and used the opportunity to promote smoking cessation for interested individuals. CONCLUSION: This cluster shows compelling evidence for smoking-related transmission of TB in Toronto. The World Health Organization has called for integration of anti-smoking efforts as a key strategy toward TB elimination. Opportunities to integrate smoking and TB work in Canada include assessment for smoking-related transmission during contact investigations, routine use of smoking cessation supports for contacts and others with latent tuberculosis infection as well as those with active TB, and public health outreach.

The Valence of Self-Generated (Status Updates) and Other-Generated (Wall-Posts) Information Determines Impression Formation on Facebook.

We examined whether self-generated (status updates) or other-generated (wall-posts) information on Facebook influenced the impression formed of the target individual. Along with examining reliance on particular types of information, we explored the valence (positive/ neutral/ negative) of the information, as reliance on self-generated or other-generated information may depend on whether self-presentation is perceived (i.e., presenting oneself positively / not negatively). Self-presentation may be perceived if the targets have positive/ neutral statuses, while negative statuses would indicate a lack of self-presentation. In line with previous research, participants should rely on other-generated information (wall-posts) to form an impression when participants are viewed to have self-presented (positive / neutral status updates), as this information could be viewed as unreliable. Forty participants rated nine Facebook profiles where statuses and wall-posts portrayed personality traits varying in valence. Each profile consisted of a neutral profile photo, three status updates (all positive, negative, or neutral) and three wall-posts (all positive, negative, or neutral). Materials were established in two pilots. Impression formation was measured as perceived social, task, and physical attractiveness of the target individual. Participants also ranked the profiles for likeability. Supporting our expectations, other-generated information (wall-posts) dominated impression formation for social attractiveness when self-generated information (status updates) was positive/ neutral. Task attractiveness was affected by information valence, regardless of source (self or other). Despite the inclusion of neutral photos, physical attractiveness was affected by self-generated information, with negative statuses lowering physical attractiveness. We suggest that these findings have implications for impression formation beyond the Facebook setting. The 557 traits analyzed in Pilot 1 are available as supporting information (S1 Dataset) and may be useful for other impression formation researchers.

Genotypic characterization of tuberculosis transmission within Toronto's under-housed population, 1997-2008.

Toronto has been the site of a recent extended tuberculosis (TB) outbreak in the homeless or under-housed population. Genotyping has identified a unique strain that continues to circulate within this population, with spread to individuals with no links to the shelter system, and anecdotally appears to progress rapidly from infection to active disease in some cases. The recent appearance and transmission of another unique strain was also identified, indicating that TB transmission continues to be a problem within the under-housed population. Enhanced surveillance utilizing molecular epidemiology is a useful tool to assist in TB control in vulnerable populations.

Duration and distance of exposure are important predictors of transmission among community contacts of Ontario SARS cases.

We report attack rates and contact-related predictors among community contacts of severe acute respiratory syndrome (SARS) cases from the 2003 Toronto-area outbreak. Community contact data was extracted from public health records for single, well-defined exposures to a SARS case. In total, 8662 community-acquired exposures resulted in 61 probable cases; a crude attack rate of 0.70% [95% confidence interval (CI) 0.54-0.90]. Persons aged 55-69 years were at higher risk of acquiring SARS (1.14%) than those either younger (0.60%) or older (0.70%). In multivariable analysis exposures for at least 30 min at a distance of

Outbreak of measles in a highly vaccinated secondary school population.

OBJECTIVE: To examine the factors associated with measles vaccine effectiveness and the effect of two doses of vaccine on measles susceptibility during an outbreak. DESIGN: Retrospective cohort study. SETTING: A secondary school in the City of Toronto. SUBJECTS: The entire school population (1135 students 14 to 21 years of age). MAIN OUTCOME MEASURES: Risk of measles during an outbreak associated with age at first measles vaccination, length of time since vaccination, vaccination before 1980 and whether date of vaccination was estimated; vaccine efficacy of one dose versus two doses. RESULTS: Eighty-seven laboratory-confirmed or clinically confirmed cases of measles were identified (for an attack rate of 7.7%). The measles vaccination rate was 94.2%, and 10% of the students had received two doses of measles vaccine before the outbreak. Among those who had received only one dose of vaccine, vaccination at less than 15 months of age was associated with vaccine failure (relative risk 3.62, 95% confidence interval 2.32 to 5.66). There was no increased risk of vaccine failure associated with length of time since vaccination once the relative risk was adjusted for age at vaccination in a stratified analysis. Vaccination before 1980 and an estimated date of vaccination were not associated with increased risk of vaccine failure. Administration of a second dose of vaccine during the outbreak was not protective. Two doses of vaccine given before the outbreak conferred significant protection, and the relative risk of failure after one dose versus two doses was 5.0 (95% confidence interval 1.25 to 20.15). Of the 87 cases, 76 (87%) could have been prevented had all the students received two doses of measles vaccine before the outbreak, with the first at 12 months of age or later. CONCLUSIONS: Delayed primary measles vaccination (at 15 months of age or later) significantly reduced measles risk at later ages. However, revising the timing of the current 12-month dose would leave children vulnerable during a period in which there is increased risk of complications. The findings support a population-based two-dose measles vaccination strategy for optimal measles control and eventual disease elimination.

Low blood lead levels in Northern Ontario - what now?

OBJECTIVE: To assess the extent of childhood lead exposure and provide guidance for public health efforts to reduce exposure in Northern communities in Ontario. DESIGN: Population-based cross-sectional survey. SETTING: Northern Ontario, September-October 1992. PARTICIPANTS: 395 children aged 1 to 6 living in Moosonee or Moose Factory (68% of all children in target group). OUTCOME MEASURES: Blood lead levels. RESULTS: The geometric mean lead level was 3.10 micro g/dL (range, 0 to 18.9 micro g/dl); 4% of children had a lead level > 10 mu g/dL, and none had levels over 20 mu g/dL. Two-year-olds and boys had the highest lead levels. CONCLUSIONS: Blood lead levels in this survey are low but unexpectedly close to inner city Toronto children in both non-point-source and point-source neighbourhoods. Population-level rather than individual interventions are required to further reduce exposure. Lead shot is among the important sources of insidious environmental lead exposure in this population and may be very important for some children involved in hunting activities. Results suggest the development of safer alternatives for lead shot.

Adult dental health in the Keewatin.

In 1990, as part of a major health status assessment, a dental survey was carried out on a 20 per cent random sample of the adult population in the Keewatin region of the Northwest Territories. A 73 per cent response rate was obtained. Of the 397 people examined, 334 (88 per cent) identified themselves as Inuit. More than 20 per cent of the respondents were edentulous, including 10 per cent of those 18 to 34 years old. The median DMFT was 24 for all respondents and 21 for dentulous respondents. There was a significant difference between Inuit and non-Inuit respondents, which was most marked in the 18 to 34 year old age group (mean DMFT 22.1 versus 15.6, p < .001). The proportion of filled to decayed and filled surfaces (F/DF) was 50 per cent. Periodontal disease was common and increased with age. More than 73 per cent of the dentate individuals had gingival bleeding at one or more sites. Very few were free of calculus. Mean pocket depth increased with age (1.3 mm at 18-34 years of age, rising to 2.3 at 55 plus, p < .001). Sixty per cent of adults needed at least one restorative procedure, 68 per cent needed prophylaxis, and 45 per cent needed periodontal treatment. Men required more treatment of all types than women. The results of this study confirm the clinical impression that dental disease is rampant among the Inuit population. There are major needs for both preventive and treatment services.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of different dosage schedules of cisapride on gastric emptying in idiopathic gastroparesis.

The aim of this study was to determine the optimal dosage regimen of cisapride for the treatment of idiopathic gastroparesis. We studied 17 patients with documented idiopathic gastroparesis in a three-way, cross-over, double-blind study with three 4-day treatment periods separated by at least 3 days without treatment. In each period, the patients were preloaded with cisapride (10 mg tid) for three days. On the fourth day (the test day) they took either 10 mg or 20 mg before breakfast and placebo before lunch (1 x 10 mg), (1 x 20 mg), or 10 mg before breakfast and 10 mg before lunch (2 x 10 mg). The medications were taken 30 min before meals. Gastric emptying of solids (99mTc-sulphur colloid) was measured at lunch time under basal conditions and during each treatment period. Plasma concentrations of cisapride were determined before the breakfast dose, before the lunch dose, and at 1, 2, 3, 4 and 5 h after. The greatest acceleration in gastric emptying occurred with the 2 x 10 mg regimen. Although the single morning dose of 20 mg also significantly accelerated gastric emptying (P = 0.05), the reduction was not as substantial. Plasma concentrations of cisapride were significantly higher after 2 x 10 mg than after 1 x 20 mg or 1 x 10 mg. There was a significant relation between cisapride plasma concentrations and changes in gastric emptying. Peak concentrations of cisapride greater than 60 ng.ml-1 were invariably associated with acceleration of gastric emptying. We conclude that cisapride 10 mg tid before meals is the optimal dose for the treatment of idiopathic gastroparesis.

Medical audit of hysterectomy in the Hunter Area of New South Wales.

A computer search in the New South Wales (NSW) Department of Health statistical data base was made to obtain the medical record numbers of patients who had had hysterectomies in the public or private hospitals of the Hunter Area of the State during the years 1987-89. The medical records of patients so identified were then extracted and reviewed by a medical team. The age at and the principal indication for hysterectomy were noted in each case and these data were then compared with those for the rest of NSW. The hysterectomy rate in the Hunter Area was 66.5 per 10,000 women aged 15 years or more, compared with a rate of 33.8 per 10,000 in the rest of NSW. When the 9.04% of hysterectomies performed on patients whose domicile was outside the Hunter Area were excluded, the corrected hysterectomy rate for the area was 57.46 per 10,000 women. The commonest indications for hysterectomy were menorrhagia (25.4%) and fibroids (15.32%). The limitations of this kind of retrospective study are discussed and suggestions are made for an improved methodology to be used in a future study.

Rapid laser-wavelength modulation spectroscopy used as a fast temperature measurement technique in hydrocarbon combustion.

A fast temperature measurement technique is described which is suitable for use in dynamic reacting gases, particularly in situations which involve hydrocarbon-air combustion. Temperature is determined from the relative intensity of a pair of fully resolved absorption lines probed with a rapid-tuning single-frequency laser. Demonstration of the technique using 300-micros scans across the R(1) (7) and R(1)(11) lines in the (0, 0) band of the A(2)Sigma(+) ? X(2)II system of OH present in the postflame gases above a CH(4)-air flat-flame burner is reported. Fluorescence monitoring of the absorption spectra was used to provide improved spatial resolution. Temperatures inferred from simultaneous absorption and fluorescence measurements showed good agreement with radiation-corrected thermocouple scans.

Effect of chronic administration of cisapride on gastric emptying of a solid meal and on dyspeptic symptoms in patients with idiopathic gastroparesis.

In a double blind crossover comparison with placebo, the effects of cisapride (10 mg tid for two weeks), a non-antidopaminergic gastrointestinal prokinetic drug, on gastric emptying times and on symptoms were evaluated in 12 patients with chronic idiopathic dyspepsia and gastroparesis. Gastric emptying was studied by a radioisotopic gamma camera technique. The test meal was labelled in the solid component (99mTc-sulphur colloid infiltrated chicken liver). Nine symptoms (nausea, belching, regurgitations, vomiting, postprandial drowsiness, early satiety, epigastric pain or burning, heartburn) were graded weekly on a questionnaire. Cisapride was significantly more effective than placebo in shortening the t1/2 of gastric emptying (p2 = 0.04), but no significant difference was observed between the two treatments with regard to the improvement of total symptom score (p2 = 0.09). No side effects were reported during the study.

Temperature measurements in shock tubes using a laser-based absorption technique.

A laser-based technique for monitoring temperature in shock tube flows is reported. The method employs a rapid-tuning ring-dye laser to record the fully resolved absorption spectrum of the R(1)(7) and R(1)(11) lines of OH near 306.5 nm. The temperature is inferred from the ratio of the peak absorption coefficients of the two lines. Comparisons with calculated reflected shock temperatures show agreement within +/-3% for the 1300-3500 K range.

[Effect of tiropramide on solid gastric emptying time in man]. / Effetto della Tiropramide sul tempo di svuotamento gastrico dei solidi, nell'uomo.

The influence of Thyropramide, a recently developed spasmolytic on the gastric emptying times of a solid meal was assessed in 10 healthy subjects aged 23-54. Thyropramide (300 mg per diem for 3 days per os) does not significantly modify gastric emptying time compared to the placebo though a slight average increase in T 1/2 was noted. No side effects were noted during the study. Thyropramide therefore appears to have a spasmolytic effect on the large intestine without in any way influence the stomach either proximally or distally.

The role of colloidal bismuth subcitrate in the short-term treatment of duodenal ulcer.

Colloidal bismuth subcitrate (CBS) is a drug used in the treatment of duodenal ulcer; it acts mainly by increasing mucosal resistance against endoluminal aggressive agents, without inhibiting gastric secretion. In previous clinical trials, CBS solution induced healing rates significantly higher than placebo and similar to those observed with cimetidine. In spite of these promising results, the drug has never been widely employed, mainly because of its unpleasant taste, which greatly reduced patient compliance. For this reason, chewing tablets have been introduced. CBS tablets have been reported to induce healing rates significantly higher than placebo and similar to those obtained with CBS solution, cimetidine, and ranitidine. CBS may therefore represent an important alternative to antisecretory drugs in the therapy of duodenal ulcer patients.

Laser-induced fluorescence technique for velocity field measurements in subsonic gas flows.

A nonintrusive optical technique is reported for multiple-point velocity measurements in subsonic flows. The technique is based on the detection of fluorescence from a Doppler-shifted absorption line of seeded iodine molecules excited at a laser frequency fixed in the wing of the line. Counterpropagating laser sheets are used to illuminate the flow, in the present case a nitrogen round jet, thereby eliminating the need for an unshifted reference signal. The fluorescence is detected simultaneously at 10,000 points in a plane of the flow using a 100 x 100 element photodiode-array camera. The velocity at each point is computed from four successive camera frames, each recorded with a different beam direction. The measured mean velocities between 5 and 50 m/sec agree well with data from the literature.