Do "Virtual" and "Outpatient" Public Health Tuberculosis Clinics Perform Equally Well? A Program-Wide Evaluation in Alberta, Canada.

BACKGROUND:Meeting the challenge of tuberculosis (TB) elimination will require adopting new models of delivering patient-centered care customized to diverse settings and contexts. In areas of low incidence with cases spread out across jurisdictions and large geographic areas, a "virtual" model is attractive. However, whether "virtual" clinics and telemedicine deliver the same outcomes as face-to-face encounters in general and within the sphere of public health in particular, is unknown. This evidence is generated here by analyzing outcomes between the "virtual" and "outpatient" public health TB clinics in Alberta, a province of Western Canada with a large geographic area and relatively small population. METHODS:In response to the challenge of delivering equitable TB services over long distances and to hard to reach communities, Alberta established three public health clinics for the delivery of its program: two outpatient serving major metropolitan areas, and one virtual serving mainly rural areas. The virtual clinic receives paper-based or electronic referrals and generates directives which are acted upon by local providers. Clinics are staffed by dedicated public health nurses and university-based TB physicians. Performance of the two types of clinics is compared between the years 2008 and 2012 using 16 case management and treatment outcome indicators and 12 contact management indicators. FINDINGS:In the outpatient and virtual clinics, respectively, 691 and 150 cases and their contacts were managed. Individually and together both types of clinics met most performance targets. Compared to outpatient clinics, virtual clinic performance was comparable, superior and inferior in 22, 3, and 3 indicators, respectively. CONCLUSIONS:Outpatient and virtual public health TB clinics perform equally well. In low incidence settings a combination of the two clinic types has the potential to address issues around equitable service delivery and declining expertise

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

TB Prevention and Care Program of Alberta: The organization of TB services in the Province of Alberta, Canada.

<p>TB services are delivered out of three public health clinics, two outpatient (the Calgary and Edmonton TB Clinics) and one virtual. The virtual clinic also maintains the TB Registry and oversees provincial program activities. Abbreviations: PHO Provincial Health Office; AH Alberta Health; AHS Alberta Health Services; PHAC Public Health Agency of Canada; CIC Citizenship and Immigration Canada; FNIHB First Nations and Inuit Health Branch; AB Alberta.</p

Individual and public health consequences associated with a missed diagnosis of pulmonary tuberculosis in the emergency department: A retrospective cohort study.

ObjectivesTo determine: i) the emergency department (ED) utilization history of pulmonary tuberculosis (PTB) patients, and ii) the potential individual and public health consequences of a missed diagnosis of PTB in this setting.DesignRetrospective observational cohort study.ParticipantsPatients with PTB aged >16 years diagnosed between April 1, 2010 and December 31, 2016 in the Province of Alberta, Canada.MethodsWe identified valid new cases of PTB from a provincial registry and linked them to ED attendees in administrative databases. Visits are considered 'PTB', pulmonary 'other', and non-pulmonary based on the most responsible discharge diagnosis. Individual consequences of a missed diagnosis included health system delay and PTB-related death; public health consequences included nosocomial ED exposure time and secondary cases.ResultsOf 711 PTB patients, 378 (53%) made 845 ED visits in the six months immediately preceding the date of diagnosis. The most responsible ED discharge diagnosis was PTB in 92 (10.9%), pulmonary 'other' in 273 (32%) and non-pulmonary in 480 (56.8%). ED attendees had a median (IQR) health system delay of 27 (7,180) days and, compared to non-ED attendees were more likely to die a TB-related death 5.9% vs 1.2%, p = 0.001. Emergency attendees generated 3812 hours of ED nosocomial exposure time, and 31 secondary cases (60.8% of all secondary cases reported). Mycobacterium tuberculosis isolates from ED-attendees were more likely than non-attendees to be clustered-i.e., have an identical DNA fingerprint with another isolate (27% vs. 21%, p = 0.037).ConclusionsED utilization by PTB patients, and related consequences, are substantial. EDs are a potential resource for earlier PTB diagnosis

Is there a fundamental flaw in Canada's post-arrival immigrant surveillance system for tuberculosis?

BackgroundNew immigrants to Canada with a history of tuberculosis or evidence of old healed tuberculosis on chest radiograph are referred to public health authorities for medical surveillance. This ostensible public health protection measure identifies a subgroup of patients (referrals) who are at very low risk (compared to non-referrals) of transmission.MethodsTo assess whether earlier diagnosis or a different phenotypic expression of disease explains this difference, we systematically reconstructed the immigration and transmission histories from a well-defined cohort of recently-arrived referral and non-referral pulmonary tuberculosis cases in Canada. Incident case chest radiographs in all cases and sequential past radiographs in referrals were re-read by three experts. Change in disease severity from pre-immigration radiograph to incident radiograph was the primary, and transmission of tuberculosis, the secondary, outcome.ResultsThere were 174 cohort cases; 61 (35.1%) referrals and 113 (64.9%) non-referrals. Compared to non-referrals, referrals were less likely to be symptomatic (26% vs. 80%), smear-positive (15% vs. 50%), or to have cavitation (0% vs. 35%) or extensive disease (15% vs. 59%) on chest radiograph. After adjustment for referral status, time between films, country-of-birth, age and co-morbidities, referrals were less likely to have substantial changes on chest radiograph; OR 0.058 (95% CI 0.018-0.199). All secondary cases and 82% of tuberculin skin test conversions occurred in contacts of non-referrals.ConclusionsPhenotypically different disease, and not earlier diagnosis, explains the difference in transmission risk between referrals and non-referrals. Screening, and treating high-risk non-referrals for latent tuberculosis is necessary to eliminate tuberculosis in Canada

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

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

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

The prevalence, risk factors, and public health consequences of peripheral lymph node–associated clinical and subclinical pulmonary tuberculosis

Objectives: Relatively little is known about the prevalence, risk factors, and public health consequences of peripheral lymph node (PLN)–associated pulmonary tuberculosis (PTB). Methods: We developed a 10-year (2010-2019) population-based cohort of PLNTB patients in Canada. We used systematically collected primary source data and expert reader chest radiograph interpretations in a multivariable logistic regression to determine associations between sputum culture positivity and demographic, clinical, and radiographic features. Public health risks were estimated among contacts of PLNTB patients. Results: There were 306 patients with PLNTB, among whom 283 (92.5%) were 15-64 years of age, 159 (52.0%) were female, and 293 (95.8%) were foreign-born. Respiratory symptoms were present in 21.6%, and abnormal chest radiograph in 23.2%. Sputum culture positivity ranged from 12.9% in patients with no symptoms and normal lung parenchyma to 66.7% in patients with both. Respiratory symptoms, abnormal lung parenchyma, and HIV-coinfection (borderline) were independent predictors of sputum culture positivity (odds ratio [OR] 2.24 [95% confidence interval [CI] 1.15-4.39], P = 0.01, OR 4.78 [95% CI 2.41-9.48], P < 0.001, and OR 2.54 [95% CI 0.99-6.52], P = 0.05), respectively. Among contacts of sputum culture-positive PLNTB patients, one secondary case and 16 new infections were identified. Conclusion: Isochronous PTB is common in PLNTB patients. Routine screening of PLNTB patients for PTB is strongly recommended

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