DNA test slashes wait times for tuberculosis diagnosis in Iqaluit
March 23, 2015
Study results prompt Government of Nunavut to fund TB test's continued use
Tuberculosis continues to be a significant public health concern in Canada's North, where testing for TB takes far longer than in the country's major centres. A paper just published by Iqaluit, Ottawa and Montreal researchers, in CHEST Journal, shows that the time it takes to diagnose and begin treating this infectious disease in Nunavut can be dramatically reduced by using a new technology — right in Iqaluit — that quickly provides accurate results.
The study showed that operating a DNA testing unit, called GeneXpert (Cepheid Inc.), in Iqaluit's hospital significantly sped up diagnosis of TB, especially for those with low levels of the bacteria in their sputum. As a result, the average time to start treatment was reduced to 1.8 days, as opposed to 7.7 days for patients with high levels of TB bacteria and 37 days for those with low levels of the bacteria.
Based on the study's results, the Government of Nunavut has just announced funding in its 2015–2016 budget that will keep the GeneXpert operating in the territory's capital.
"These findings represent a significant improvement in the quality of care clinicians can provide in managing this persistent and devastating disease in Canada's North — for individual patients and for the community," said Dr. Gonzalo Alvarez, a scientist and respirologist at The Ottawa Hospital and an associate professor at the University of Ottawa. "We are very pleased to see that the Government of Nunavut has made GeneXpert a part of its program to fight TB."
The incidence of active tuberculosis in Nunavut remains the highest in Canada. In 2014, there were 83 residents of Nunavut treated for active TB, an infection rate 49 times the Canadian average. Despite the high rate, there is no TB laboratory capacity in Nunavut. Samples are sent to Ottawa for testing.
The quick test results from GeneXpert also mean that people can be quickly cleared of the disease in order to travel on a commercial airline, be released from hospital, return to work, or go to work at a camp or on a ship.
Working in partnership with the Government of Nunavut and Nunavut Tunngavik Inc., and with funding from the Canadian Institutes of Health Research, Drs. Gonzalo Alvarez and Madhukar Pai, an associate professor at McGill University and researcher at the Research Institute of the McGill University Health Centre, implemented the GeneXpert TB testing unit in Iqaluit, Nunavut, as part of a pragmatic research study that started in 2012.
GeneXpert is a desktop lab-in-a-box that identifies the presence of the TB bacteria's genetic code. The technology has been successfully used in countries with a high burden of the disease and minimal resources. Drs. Alvarez and Pai wanted to see whether GeneXpert could provide accurate results in the real-world situation of Canada's North as a way to reduce the wait times before starting treatment and, importantly, to minimize continued spread of the disease.
To do this, they designed a study that would test the technology in action, in which the GeneXpert unit was operated as part of the community's hospital laboratory. In cases of suspected TB, they used the GeneXpert test and also sent sputum samples to an Ottawa lab for testing — the current practice. The lab in Ottawa performed two tests: a smear test and a culture test. When there is a lot of tuberculosis in the sample, the smear test generally catches the disease. If there isn't, then it is diagnosed by culturing the sample, which takes longer but is the gold standard.
To look at it from the patient perspective, it would mean going to the clinic suffering from a chronic cough, fever and some mild weight loss. If TB was suspected, the patient gives a sample and the next day the GeneXpert result shows the presence of active TB. After giving the sample, the patient starts intensive TB treatment 1.8 days later. Then, 7.7 days after that first visit, the smear test results come back negative from Ottawa – no active TB found. At around day 21, the patient's cough subsides; the person is gaining weight and no longer has a fever. More than two weeks later (day 37), the culture test comes back positive from Ottawa. Without the GeneXpert test, this is when treatment would have started.
"It's cases like this, and in remote settings with no on-site TB testing capacity, where GeneXpert can make the greatest difference," said Dr. Pai, an associate director at the McGill International TB Centre. " Our study findings validate recommendations in the Canadian TB Standards that support using this technology, in this way, where routine smear and culture tests can't be done locally.”
According to public health officials in Nunavut, two-thirds of all TB cases between 1999 and 2011 were only confirmed by the culture test, like the person in the example above.
The paper titled "The feasibility, accuracy and impact of Xpert MTB.RIF testing in a remote Aboriginal community in Canada" was published early online on March 19, 2015, by CHEST Journal. It was funded by the Canadian Institutes of Health Research. The Government of Nunavut purchased the GeneXpert unit and provided in-kind support to house and operate it. Co-authors: Deborah D. Van Dyk, Marc Desjardins, Abdool S. Yasseen, Shawn D. Aaron, D. William Cameron, Natan Obed, Maureen Baikie, Smita Pakhale, Claudia M .Denkinger, Hojoon Sohn.
“The research findings confirm that this new technology can provide a significantly earlier confirmation of active tuberculosis in our territory. Earlier diagnosis and treatment decreases the spread of TB and is an important step toward our ultimate goal of eliminating TB in Nunavut. I commend and give my thanks to the cooperative efforts of Dr. Alvarez, the research partners, and our health professionals in pioneering the use of the GeneXpert technology in Iqaluit.”
—Hon. Paul Okalik, Minister of Health, Government of Nunavut
"The shortened period for diagnosis means patients can access treatment more quickly and return to their normal routines. This is a critical development for Inuit who have felt the impacts of TB in our families and communities for decades. With advancements such as this, we know that our painful history with TB has ended, and that we now can readily access better diagnosis and treatment. I hope to see this new technology become more widely available to Inuit in all Nunavut communities affected by TB.”
—Cathy Towtongie, President, Nunavut Tunngavik Inc.
For further information, please contact
Communications and Public Relations
Ottawa Hospital Research Institute
(o) 613-737-8899 x73325 or (c) 613-614-5253
Media Relations Office
Public Affairs & Strategic Planning
McGill University Health Centre
(o) 514-934-1934, ext. 71440
Ottawa Hospital Research Institute
The Ottawa Hospital Research Institute is the research arm of The Ottawa Hospital and is an affiliated institute of the University of Ottawa, closely associated with its faculties of Medicine and Health Sciences. The Ottawa Hospital Research Institute includes more than 1,700 scientists, clinical investigators, graduate students, postdoctoral fellows and staff conducting research to improve the understanding, prevention, diagnosis and treatment of human disease. Support our research. Give to the Tender Loving Research campaign.
University of Ottawa: A crossroads of cultures and ideas
The University of Ottawa is home to almost 50,000 students, faculty and staff, who live, work and study in both French and English. Our campus is a crossroads of cultures and disciplines, where bold minds come together to inspire game-changing ideas. We are one of Canada’s top 10 research universities — our professors and researchers explore new approaches to today’s challenges. One of a handful of Canadian universities ranked among the top 200 in the world, we attract exceptional thinkers and welcome diverse perspectives from across the globe.
McGill University Faculty of Medicine
McGill University was founded in 1821 thanks to a generous bequest by James McGill, and since then has grown from a small college to a bustling university with two campuses, 11 faculties, some 300 programs of study, and 39,500 students. Founded in 1829, McGill’s Faculty of Medicine was the first faculty established at the University and the first medical faculty in Canada. Today, it comprises the Schools of Medicine, Physical and Occupational Therapy, and Communication Sciences and Disorders, and the Ingram School of Nursing, offering excellence in post-secondary education and research. Through the Réseau universitaire intégré de santé McGill, the Faculty of Medicine, together with its network of affiliated teaching hospitals and partners, is also responsible for coordinating access to training, research and health care for close to 1.8 million Quebecers across 63 per cent of the province’s landmass. www.mcgill.ca/medicine
Research Institute of the MUHC
The Research Institute of the McGill University Health Centre (RI-MUHC) is a world-renowned biomedical and healthcare research centre. Located in Montreal, Quebec, Canada, the Institute is the research arm of the McGill University Health Centre (MUHC), which is affiliated with the Faculty of Medicine at McGill University. The Research Institute supports over 550 researchers, over 1,200 graduate students, post-docs and clinical fellows devoted to a broad spectrum of fundamental clinical, and health outcomes research. Over 1,900 clinical research studies are conducted within our hospitals each year. The Research Institute of the MUHC is supported in part by the Fonds de recherche du Québec - Santé (FRQS). www.muhc.ca/research/