Epidemiology, clinical features and outcomes of incident tuberculosis in children in Canada in 2013-2016: results of a national surveillance study

PURPOSE

Childhood tuberculosis disease is difficult to diagnose and manage and is an under-recognised cause of morbidity and mortality. Reported data from Canada do not focus on childhood tuberculosis or capture key epidemiologic, clinical and microbiologic details. The purpose of this study was to assess demographics, presentation and clinical features of childhood tuberculosis in Canada.

METHODS

We conducted prospective surveillance from 2013 to 2016 of over 2700 paediatricians plus vertical tuberculosis programmes for incident tuberculosis disease in children younger than 15 years in Canada using the Canadian Paediatric Surveillance Program (CPSP).

RESULTS

In total, 200 cases are included in this study. Tuberculosis was intrathoracic in 183 patients of whom 86% had exclusively intrathoracic involvement. Central nervous system tuberculosis occurred in 16 cases (8%). Fifty-one per cent of cases were hospitalised and 11 (5.5%) admitted to an intensive care unit. Adverse drug reactions were reported in 9% of cases. The source case, most often a first-degree relative, was known in 73% of cases. Fifty-eight per cent of reported cases were Canadian-born Indigenous children. Estimated study rates of reported cases (per 100 000 children per year) were 1.2 overall, 8.6 for all Indigenous children and 54.3 for Inuit children.

CONCLUSION

Childhood tuberculosis may cause significant morbidity and resource utilisation. Key geographies and groups have very high incidence rates. Elimination of childhood tuberculosis in Canada will require well-resourced community-based efforts that focus on these highest risk groups.

Tuberculosis in Canada - Summary 2015

BACKGROUND

Tuberculosis (TB) is a global health problem that affects an estimated 10 million people each year. In Canada, the Public Health Agency of Canada (PHAC) monitors active TB disease through the Canadian Tuberculosis Reporting System (CTBRS).

OBJECTIVE

To report on and analyze the number of new and re-treatment cases of TB cases in Canada reported for 2015. Results are discussed in the context of previous year's data. Treatment outcomes for cases diagnosed in 2014 are also presented.

METHODS

The CTBRS is a case-based surveillance system that maintains non-nominal data on active cases of TB. Data are collected and analyzed by PHAC and validated by each province and territory; no statistical tests were used.

RESULTS

A total of 1,639 cases of active TB disease were reported in 2015, representing a slight increase from the number of cases reported in 2014 (1,614) and a corresponding increase in the incidence rate from 4.5 per 100,000 to 4.6 per 100,000 population. Although the incidence rate of TB remained highest in Nunavut at 119.2 per 100,000 population in 2015, it was nearly half of what it was in 2014. An outbreak in Newfoundland and Labrador resulted in a notable increase in the number of reported cases and incidence rate in this province. In 2015, males accounted for just over half of the reported cases at 53% and older Canadians carried the highest burden of TB with an incidence rate of 10.3 per 100,000 population. Foreign-born individuals continued to account for the majority of reported cases at 71%, but the incidence rate remained highest among Canadian-born Indigenous people at 17.1 per 100,000 population and in particular within the Inuit population at 166.2 per 100,000. Pulmonary TB remained the most commonly reported site of disease. Treatment outcome data for cases reported in 2014 indicated that 85% of cases had been cured or had completed treatment.

CONCLUSION

Tuberculosis rates in Canada have changed little over the last decade and overall, remain stable and low in the global context. However, foreign-born individuals and Indigenous Canadians continued to be disproportionately represented among reported cases of TB in 2015. As the primary source of national data on TB cases, the data within this report provide timely information for public health action, as well as policy and program development and assessment.

Stochastic agent-based modeling of tuberculosis in Canadian Indigenous communities

Background

In Canada, active tuberculosis (TB) disease rates remain disproportionately higher among the Indigenous population, especially among the Inuit in the north. We used mathematical modeling to evaluate how interventions might enhance existing TB control efforts in a region of Nunavut.

Methods

We developed a stochastic, agent-based model of TB transmission that captured the unique household and community structure. Evaluated interventions included: (i) rapid treatment of active cases; (ii) rapid contact tracing; (iii) expanded screening programs for latent TB infection (LTBI); and (iv) reduced household density. The outcomes of interest were incident TB infections and total diagnosed active TB disease over a 10- year time period.

Results

Model-projected incidence in the absence of additional interventions was highly variable (range: 33–369 cases) over 10 years. Compared to the ‘no additional intervention’ scenario, reducing the time between onset of active TB disease and initiation of treatment reduced both the number of new TB infections (47% reduction, relative risk of TB = 0.53) and diagnoses of active TB disease (19% reduction, relative risk of TB = 0.81). Expanding general population screening was also projected to reduce the burden of TB, although these findings were sensitive to assumptions around the relative amount of transmission occurring outside of households. Other potential interventions examined in the model (school-based screening, rapid contact tracing, and reduced household density) were found to have limited effectiveness.

Conclusions

In a region of northern Canada experiencing a significant TB burden, more rapid treatment initiation in active TB cases was the most impactful intervention evaluated. Mathematical modeling can provide guidance for allocation of limited resources in a way that minimizes disease transmission and protects population health.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3996-7) contains supplementary material, which is available to authorized users.

A population-based study of tuberculosis case fatality in Canada: do Aboriginal peoples fare less well?

SETTING

The Province of Alberta, Canada.

OBJECTIVES

To explore trends in tuberculosis (TB) case fatality, compare TB case-fatality rates by population group and determine prognostic factors associated with TB-related death in Alberta from 1996 to 2012.

DESIGN

Retrospective cohort analysis.

RESULTS

During the study years, all-cause TB case fatality fell from 10.7% to 6.3%; the fall was attributable to a change in population structure, as there were more foreign-born and fewer older cases with time. A stable 2% of TB cases died without treatment. Compared to other population groups, Canadian-born Aboriginal case patients were more likely to die without treatment and to die younger. Of TB deaths that were TB-related, 68.9% occurred before or during the initial phase of treatment; of these, TB was a contributory cause of death in 77.5%, i.e., another medical condition was the primary cause of death. In multivariate analysis, age >64 years, aboriginality and miliary/disseminated or central nervous system disease were independent predictors for TB-related death.

CONCLUSION

Preventive therapy for those with latent tuberculous infection and a high-risk medical condition, early diagnosis of disease, and special support of older, Aboriginal or comorbid cases, once diagnosed, are necessary to further minimise TB case fatality in Alberta, Canada.

Multidrug and extensively drug-resistant tuberculosis in Canada 1997-2008: demographic and disease characteristics

Setting

Nationwide Canadian public health surveillance.

Objective

Description of demographic features and disease characteristics of drug-resistant tuberculosis (TB) in Canada over a 12 year period.

Design

Continuous surveillance of all cases of culture-confirmed TB in Canada. Demographic and microbiologic features were analyzed and comparisons between drug-susceptible, multidrug-resistant (MDR), and drug-resistant not-MDR were made. Cases of extensively drug resistant TB are described.

Results

15,993 cases of culture-confirmed TB were reported during the study period. There were 5 cases of XDR-TB, 177 cases of MDR-TB, and 1,234 cases of first-line drug resistance not-MDR. The majority of drug-resistant cases were reported in foreign-born individuals, with drug-resistant cases diagnosed earlier post-arrival in Canada compared to drug-susceptible cases. In MDR-TB isolates, there was a high rate of drug-resistance to other first- and second-line drugs, making reliable empiric therapeutic recommendations for MDR-TB difficult. There was a statistically significant association between both MDR and drug-resistance not-MDR, and the risk of a negative treatment outcome (defined as treatment failure, absconded, or treatment ongoing >3 yrs).

Conclusion

Drug-resistance complicates TB management even in developed nations with well-established TB control programs. The predominantly international origin of drug-resistant cases highlights the need for global strategies to combat TB.

Mature Results of the Ottawa Phase II Study of Intermittent Androgen-Suppression Therapy in Prostate Cancer: Clinical Predictors of Outcome

PURPOSE

To present the mature experience of a phase II trial of intermittent androgen suppression (IAS).

METHODS AND MATERIALS

Intermittent androgen-suppression therapy was initiated in prostate-cancer patients to delay hormone resistance and minimize potential side effects of androgen-deprivation therapy (ADT). Patients received cyclical periods of ADT and observation (off-treatment interval [OTI]). Androgen-deprivation therapy was reinitiated when the level of prostate-specific antigen (PSA) rose above 10 ng/ml, or for disease progression. Associations between clinical factors and eligibility for OTI were measured. Kaplan-Meier and Cox regression analyses were used to determine factors predicting the duration of OTIs.

RESULTS

Ninety-five patients completed 187 cycles of treatment. The median duration of OTIs was 8.5 months. Patients with higher PSA and metastatic disease were less likely to be eligible for the first OTI (p < 0.01). In multivariate analysis, patients with higher PSA and local relapse had significantly longer OTIs (p < 0.01) compared with metastatic patients. The median time to withdrawal from the study was 37 months.

CONCLUSIONS

Intermittent androgen suppression appears to be a favorable treatment option for patients with biochemically (according to level of PSA) or locally recurrent prostate cancer with favorable long-term survival, a high probability of eligibility for OTIs, and durable OTIs.

Efficacy and compliance of small-bore chest tube insertion and pleurodesis protocols for the treatment of malignant pleural effusions

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Background: Small-bore chest tubes are now recognized as a safe and effective alternative to large-bore catheter chest tubes for the treatment of malignant pleural effusions (MPEs). The Ottawa Hospital (TOH) developed protocols for insertion and pleurodesis to maximize efficiency and minimize complications. Objective: To evaluate the efficacy and compliance of small-bore chest tube insertion and pleurodesis protocols for the treatment of MPEs. Methods: Retrospective chart review of TOH medical oncology inpatients treated for a MPE using our small-bore chest tube insertion and pleurodesis protocols from February 2003 to May 2004. Outcomes reviewed included deviations from protocol (major and minor), proportion of patients proceeding to pleurodesis and efficacy at six weeks, complications, as well as length of hospital stay. Results: One-hundred and fourteen potential cases were identified, of those 78 small-bore chest tubes were inserted into 72 patients. Major deviations from the chest tube protocol occurred in 21 patients (27%) who lacked microbiological analysis of their pleural fluid. Major complications of tube insertion occurred in ten patients (13%) who developed pulmonary infections and two patients (2.5%) who developed a significant pneumothorax. Of the 78 tube insertions, 24 cases went on to pleurodesis. Major deviations from our pleurodesis protocol occurred in five patients (2.1%) who failed to have a chest xray twenty-four hours prior to pleurodesis. The most common complication post pleurodesis was pain with seven of 24 patients (29%) rating their pain as severe. Fifteen of the 24 patients (63%) had fluid reaccumulation within six-weeks post pleurodesis. Median length of stay for patients without pleurodesis versus those with pleurodesis was 14.5 and 16.0 days, respectively. Conclusions: Our preliminary data suggests that chest tube insertion and pleurodesis protocols have good compliance rates with low rates of complications. Only a minority of patients were able to proceed to pleurodesis and long term control of effusion occurs in less than half of patients in this subgroup. As well, pain control at the time of pleurodesis was not adequate in one third of patients with the current protocol.

No significant financial relationships to disclose.

Smoking is associated with worse outcomes in patients with prostate cancer treated by radical radiotherapy

OBJECTIVE

To investigate the effect of smoking on the outcome in a cohort of men treated for localized prostate cancer at one institution with a uniform protocol of radical external beam radiotherapy (EBRT).

PATIENTS AND METHODS

The study was a retrospective review of 434 patients with cT1-T4 N0m0 prostate cancer treated with curative intent with EBRT (66 Gy in 33 fractions) between 1990 and 1999. Univariate and multivariate Cox regression analyses were used to estimate the risk associated with smoking on biochemical failure (American Society for Therapeutic Radiology and Oncology definition), local failure, distant failure, overall and disease-specific survival.

RESULTS

The median follow-up was 70.3 months. A smoking history was obtained in 96% of cases; 16.8% were current smokers, 54.4% previous smokers and 28.8% non-smokers. Current smokers presented at a younger median age, by 3.6 years (P = 0.06). There were no differences in clinical T stage, Gleason score or prostate-specific antigen level amongst the three patient groups. Smoking conferred a higher risk of developing metastatic disease in both current smokers (hazard ratio 5.24; 95% confidence interval 1.75-15.72) and previous smokers (2.90, 1.09-7.67). There were also increases in risk, although not quite significant, for biochemical failure (1.49, 0.88-2.40) and overall survival (1.72, 0.94-3.15).

CONCLUSIONS

After curative treatment with EBRT, a history of smoking was associated with a greater risk of developing metastatic disease. Smoking status was not associated with worse disease on presentation.

The Preferred Treatment for Stage I Seminoma: A Survey of Canadian Radiation Oncologists

AIMS

To evaluate the preferences of radiation oncologists for managing stage I seminoma.

MATERIALS AND METHODS

An electronic survey evaluating the management of stage I seminoma patients was sent to Canadian radiation oncologists to determine their treatment recommendations and preferences.

RESULTS

The survey completion rate was 74% among eligible respondents (78/105). Most (56%) felt that surveillance was the preferred treatment for patients, whereas 31% thought that adjuvant radiotherapy was best, 1% chose adjuvant chemotherapy as being the preferred option and 12% were unsure. Most would choose the same treatment for themselves if they were diagnosed with stage I seminoma. A previously published survey found that most respondents considered radiotherapy as the best option.

CONCLUSIONS

Most Canadian radiation oncologists now favour surveillance for most stage I seminoma patients.

Effective palliative radiotherapy for symptomatic recurrent or residual ovarian cancer

OBJECTIVE

To evaluate the efficacy of radiotherapy (RT) for symptomatic recurrent or residual ovarian cancer.

METHODS

A review was conducted on patients (pts) treated with palliative RT for symptomatic ovarian cancer at The Ottawa Hospital Regional Cancer Centre between 1990 and 2003. Patient demographics, tumor factors, treatment variables, and clinical outcome were entered into a database. Symptom response was defined as complete (CR), partial (PR), or none.

RESULTS

62 courses of RT were delivered to 53 pts. The symptoms treated were: bleeding (40%), pain (37%), and "others" (23%). The most common dose fractionation scheme was 30 Gy in 10 fractions (f) (range: 5 Gy/1 f to 52.5 Gy/20 f). The overall response rate was 100%, with 68% achieving a CR. The CR rates were 88, 65, and 36% for the symptoms of bleeding, pain, and "others", respectively (P = 0.003). The median duration of response was 4.8 months (range: 1-71 months). In multivariate analysis, the only factors that were found to be significant positive predictors of symptom control were: the symptom bleeding (P = 0.015) and stage III/IV disease at presentation (P = 0.01). The most commonly reported toxicities were grades 1 and 2 nausea/vomiting and diarrhea. There were no grade 3/4 toxicities reported.

CONCLUSIONS

Radiotherapy is highly effective in palliating symptomatic ovarian cancer. Excellent results are achieved for patients presenting with bleeding or pain. Symptomatic patients should be strongly considered for palliative radiotherapy. Higher doses of radiotherapy should be considered for those with symptoms other than bleeding or pain and those with longer life expectancies.

Treatment of stage I seminoma: A 15-year review

PURPOSE

To review the treatment and outcomes in patients with stage I seminoma after orchidectomy.

METHODS

A retrospective chart review of all patients with stage I seminoma referred for initial treatment during the last 15 years was performed. Initial treatment approaches and outcomes were analyzed. Comparisons were made between patients treated with adjuvant radiotherapy and those receiving no adjuvant therapy (surveillance group).

RESULTS

A total of 150 patients with stage I seminoma was seen between 1989 and 2003. Median age at diagnosis was 37.5 years (range 19-79), with a median follow-up of 54 months (range 1-162). Of the patients, 71% were treated with adjuvant radiotherapy, and 29% were placed on a surveillance protocol. The 5-year relapse-free survival and overall survival for the entire group were 95% and 100%, respectively. The 5-year relapse-free survival for the adjuvant radiotherapy group was 100% compared with 79% for the surveillance group (P < 0.001). Of the 6 patients who had a relapse, 5 were salvaged with radiation, but 1 required chemotherapy as well. One patient who had a relapse is currently refusing treatment for recurrence.

CONCLUSIONS

Our results confirm the excellent prognosis for patients with stage I seminoma and indicate that surveillance does not compromise survival. This result adds to the evidence that surveillance is a good option for many patients and also supports our current approach, which favors surveillance for most patients with stage I seminoma after orchidectomy who are willing to go on our surveillance protocol.

A prospective clinical trial of green tea for hormone refractory prostate cancer: an evaluation of the complementary/alternative therapy approach

PURPOSE

To evaluate the efficacy and toxicity of green tea, prescribed as an alternative complementary (CAM) formulation on hormone refractory prostate cancer (HRPC).

METHODS

Patients with HRCP were prescribed green tea extract capsules at a dose level of 250 mg twice daily. Efficacy and toxicity were evaluated during monthly visits. The primary endpoint was prostate-specific antigen (PSA) or measurable disease progression after a minimum of 2 months of therapy.

RESULTS

Nineteen patients were enrolled into the study. The treatment was generally well tolerated. Twelve patients reported at least one side effect; only two of these were of moderate or severe grade. Primary toxicity was related to gastrointestinal irritation or caffeine intake. Four patients did not complete the minimum 2 months of therapy because of: intolerance (two patients), physician stoppage (one patient), death from cerebrovascular accident (one patient). Fifteen patients completed at least 2 months of therapy. Nine of these patients had progressive disease within 2 months of starting therapy. Six patients developed progressive disease after additional 1 to 4 months of therapy.

CONCLUSION

Green tea, as CAM therapy, was found to have minimal clinical activity against hormone refractory prostate cancer.