The Feasibility, Accuracy, and Impact of Xpert MTB/RIF Testing in a Remote Aboriginal Community in Canada.

BACKGROUND: Xpert MTB/RIF testing for Mycobacterium tuberculosis and rifampin resistance is being used extensively in countries with a high burden of TB. However, recent evidence suggests that it may not have the same accuracy or impact in high-income, low-burden TB countries. METHODS: A prospective, pragmatic study was done between March 2012 and March 2014 to determine the feasibility, accuracy, and impact on TB disease management provided by the Xpert test in a remote, medically underserved, predominantly Inuit population in Iqaluit, Nunavut, Canada. RESULTS: A total of 453 Xpert tests were run on sputum samples from 344 patients with suspected TB. Twenty-seven patients were identified as having active TB disease by culture. There were no cases of drug-resistant TB. Using culture as the gold standard, one Xpert test compared with one, two, or three sputum samples cultured per patient had a sensitivity of 85% (95% CI, 66%-95%) and a specificity of 99% (95% CI, 97%-100%) for detection of M tuberculosis. The indeterminate rate was 4.4% of all samples run. Treatment initiation was significantly shortened using Xpert vs the national standard of three smears (1.8 days vs 7.7 days, P < .007) and particularly shorter in smear-negative, culture-positive cases (1.8 days vs 37.1 days, P < .008). CONCLUSIONS: In a predominantly Inuit population in a remote region of Canada where the burden of TB is high and no TB testing facilities are available, onsite Xpert testing was feasible and accurate and shortened the time to TB treatment initiation.

The feasibility of the interferon gamma release assay and predictors of discordance with the tuberculin skin test for the diagnosis of latent tuberculosis infection in a remote Aboriginal community.

BACKGROUND: The tuberculin skin test (TST) is the standard test used to screen for latent TB infection (LTBI) in the northern Canadian territory of Nunavut. Interferon gamma release assays (IGRA) are T cell blood-based assays to diagnose LTBI. The Bacillus Calmette-Guerin (BCG) vaccine is part of the routine immunization schedule in Nunavut. The objective of this study was to test the feasibility, and predictors of discordance between the Tuberculin Skin Test (TST) and the IGRA assay in a medically under-serviced remote arctic Aboriginal population. METHODS: Both the TST and QuantiFERON-TB Gold (Qiagen group) IGRA tests were offered to people in their homes as part of a public health campaign aimed at high TB risk residential areas in Iqaluit, Nunavut, Canada. Feasibility was measured by the capacity of the staff to do the test successfully as measured by the proportion of results obtained. RESULTS: In this population of predominantly young Inuit who were mostly BCG vaccinated, the use of IGRA for the diagnosis of LTBI was feasible. IGRA testing resulted in more available test results reaching patients (95.6% vs 90.9% p = 0.02) but took longer (median 8 days (IGRA) vs 2 days (TST), p value < 0.0001). 44/256 participants (17.2%) had discordant results. Multivariable regression analysis suggested that discordant results were most likely to have received multiple BCG vaccinations (RR 20.03, 95% CI, 3.94-101.82)), followed by BCG given post infancy (RR 8.13, 95% CI, 2.54-26.03)) and then to a lesser degree when BCG was given in infancy (RR 6.43, 95% CI, 1.72-24.85). INTERPRETATION: IGRA is feasible in Iqaluit, Nunavut, a remote Arctic community. IGRA testing results in more test results available to patients compared to TST. This test could result in fewer patients requiring latent TB treatment among those previously vaccinated with BCG in a region with limited public health human resources.

Taima (stop) TB: the impact of a multifaceted TB awareness and door-to-door campaign in residential areas of high risk for TB in Iqaluit, Nunavut.

BACKGROUND: The incidence rate of active tuberculosis (TB) disease in the Canadian Territory of Nunavut has shown a rising trend over the past 10 years. In 2010 it was 60 times greater than the national incidence rate. The objective of the Taima (translates to "stop" in Inuktitut) TB study was to implement and evaluate a public health campaign to enhance existing TB prevention efforts in Nunavut. METHODS: A TB awareness campaign followed by a door-to-door screening campaign was carried out in Iqaluit, Nunavut. The aim of the campaign was to raise awareness about TB, and to provide in-home screening and treatment for people living in residential areas at high risk for TB. Screening was based on geographic location rather than on individual risk factors. RESULTS: During the general awareness campaign an increase in the number of people who requested TB testing at the local public health clinic was observed. However, this increase was not sustained following cessation of the awareness campaign. Targeted TB screening in high risk residential areas in Iqaluit resulted in 224 individuals having TSTs read, and detection of 42 previously unidentified cases of latent TB, (overall yield of 18.8% or number needed to screen = 5.3). These cases of latent TB infection (LTBI) were extra cases that had not been picked up by traditional screening practices (34% relative increase within the community). This resulted in a 33% relative increase in the completion of LTBI treatment within the community. The program directly and indirectly identified 5/17 new cases of active TB disease in Iqaluit during the study period (29.5% of all incident cases). CONCLUSIONS: While contact tracing investigations remain a cornerstone of TB prevention, additional awareness, screening, and treatment programs like Taima TB may contribute to the successful control of TB in Aboriginal communities.

The development of a comprehensive maternal-child health information system for Nunavut-Nutaqqavut (Our Children).

OBJECTIVES: Nunavut is the most northerly jurisdiction in Canada of which 85% of inhabitants are Inuit. Although most infants are born healthy, Nunavut leads the country for adverse early child health outcomes such as infant mortality, rates of birth defects, prematurity and low birth weight. Public health and community efforts are needed to understand and improve outcomes. METHODS: To inform these issues, a combined University of British Columbia/Nunavut Public Health Strategy effort has initiated a comprehensive maternal-child health surveillance system (from 16 weeks gestation to age 5). A diverse group of professional and lay stakeholders were brought together initially to determine local interest. Following this, a series of small working groups were held to decide on potential prenatal, perinatal and early child health variables, to be documented. RESULTS: Over 100 Nunavut participants have now had some role in the development of the system which has been initiated. Pre-existing standard prenatal forms and well-child assessment forms have been modified to include "Nunavut specific" variables of nutrition, food and domestic security, exposures in pregnancy, birth defects, development, chronic diseases of childhood and paternal information. CONCLUSION: This comprehensive maternal-child health information system has been developed with the extensive input of health care providers and stakeholders, utilizing community and public health systems already in place. Careful assessment of local needs has contributed to database development, privacy protection, potential data utilization for health promotion and plans for dissemination of findings. It is hoped that this will be a user-friendly surveillance system, adaptable to other community and public health systems that will improve the understanding of Aboriginal maternal-child health determinants.