Barriers to the recognition and reporting of occupational asthma by Canadian pulmonologists

BACKGROUND: Occupational asthma is a common, but probably under-recognized problem

Is early tuberculosis death associated with increased tuberculosis transmission?

Tuberculosis (TB) is now a relatively uncommon disease in high income countries. As such, its diagnosis may be missed or delayed resulting in death before or shortly after the introduction of treatment. Whether early TB death is associated with increased TB transmission is unknown. To determine the transmission risk attributable to early TB death we undertook a case-control study.All adults who were: (1) diagnosed with culture-positive pulmonary TB in the Province of Alberta, Canada between 1996 and 2012, and (2) died a TB-related death before or within the first 60 days of treatment, were identified. For each of these "cases" two sets of "controls" were randomly selected from among culture-positive pulmonary TB cases that survived beyond 60 days of treatment. "Controls" were matched by age, sex, population group, +/- smear status. Secondary cases of "cases" and "controls" were identified using conventional and molecular epidemiologic tools and compared. In addition, new infections were identified and compared in contacts of "cases" that died before treatment and contacts of their smear-matched "controls". Conditional logistic regression was used to find associations in both univariate and multivariate analysis."Cases" were as, but not more, likely than "controls" to transmit. This was so whether transmission was measured in terms of the number of "cases" and smear-unmatched or -matched "controls" that had a secondary case, the number of secondary cases that they had or the number of new infections found in contacts of "cases" that died before treatment and their smear-matched "controls".In a low TB incidence/low HIV prevalence country, pulmonary TB patients that die a TB-related death before or in the initial phase of treatment and pulmonary TB patients that survive beyond the initial phase of treatment are equally likely to transmit

Tuberculin skin test results in contacts of “cases” that died before treatment (n = 15) and their matched (for age, sex, population group and smear status) “controls” (n = 30).

<p>Abbreviations: TST tuberculin skin test</p><p>* New positive TSTs and TST converters were defined according to the Canadian TB Standards, 7^th Edition</p><p>† TST converters include those contacts diagnosed with prevalent active TB</p><p>Tuberculin skin test results in contacts of “cases” that died before treatment (n = 15) and their matched (for age, sex, population group and smear status) “controls” (n = 30).</p

Adult culture-positive pulmonary TB cases that died either before or within the first 60 days of treatment, according to time of death and cause of death (“cases” in the case-control analysis).

<p>Adult culture-positive pulmonary TB cases that died either before or within the first 60 days of treatment, according to time of death and cause of death (“cases” in the case-control analysis).</p

TB Cases in Alberta from 1996–2012: Cases with Early Death and Other Outcomes.

<p>TB Cases in Alberta from 1996–2012: Cases with Early Death and Other Outcomes.</p

Identified contacts of “cases” and “controls” by age, sex and smear status of source case or control.

<p>* p < 0.05: conditional logistic regression with logarithm transformation of number of contacts. We imputed 0.01 as the number of contacts for patients who have no contact.</p><p>Identified contacts of “cases” and “controls” by age, sex and smear status of source case or control.</p

Demographic and clinical characteristics of pulmonary tuberculosis patients who died before or within 60 days of treatment (cases) or survived beyond 60 days of treatment (controls).

<p>*One set of controls was matched by age (± 5 years), sex and population group. Another set of controls was matched by age, sex, population groups and smear status. Among the controls matched by age (± 5 years), sex, population group and smear status there were 8 that could only by matched by age ± 10 years</p><p>^†Canadian-born Aboriginal includes individuals identified as First Nations, Métis, or Inuit according to the <i>Constitution Act</i> of 1982</p><p>^‡p < 0.05</p><p>^§Only multidrug-resistant cases (defined as resistance to isoniazid and rifampin with or without resistance to other drugs), were included.</p><p>Demographic and clinical characteristics of pulmonary tuberculosis patients who died before or within 60 days of treatment (cases) or survived beyond 60 days of treatment (controls).</p

Characteristics of early TB deaths that were “case transmitters” and characteristics of their secondary cases.

<p>Abbreviations: M male; F female; CBA Canadian-born Aboriginal; CBO Canadian-born “Other”; FB Foreign-born; Tx treatment; Dx diagnosis; Hosp hospital; COPD Chronic Obstructive Pulmonary Disease; CVA cerebro-vascular accident</p><p>*See text for definitions of type of secondary case.</p><p>†Time to diagnosis is the number of days between the diagnosis of the “case transmitter” and the diagnosis of the secondary case.</p><p>Characteristics of early TB deaths that were “case transmitters” and characteristics of their secondary cases.</p