TB among aboriginal Canadians

[The authors respond:]

We appreciate Leo Kahana's interest in our article on tuberculosis in aboriginal people in Canada.1 He raises a number of important issues. We did not address the history of tuberculosis in Canada, as this subject had already been adequately covered by an earlier article in the CMAJ series on tuberculosis.2 We indicated that the role of bacillus Calmette-Guérin vaccination in tuberculosis control is controversial. Kahana quotes reports showing a wide range of efficacy, but efficacy within Canada, which is most pertinent to our review, shows a significant benefit in case-controlled studies.3 Many studies have shown underutilization of isoniazid chemoprophylaxis to be detrimental to tuberculosis control programs. The article by Mitchell and colleagues that Kahana cites refers to patients on active treatment;4 one of us (J.M.F.) responded to this report with suggestions about a nonhepatoxic regimen.5 There are no data on the combined use of rifampin and levofloxacin for chemoprophylaxis. Apart from toxicity, use of an expensive quinolone would incur significant additional costs. We are currently collaborating with the Tuberculosis Clinical Trials Consortium of the Centers for Disease Control and Prevention in Atlanta to develop a protocol to assess the efficacy of short-course chemoprophylaxis in non-HIV-infected people, which we hope will provide an alternative short-course regimen.

We disagree with Kahana's suggestion that we were patronizing in the section on health transfer. We welcome the concept of health transfer but caution that a public health surveillance system must remain in place. Our final conclusion was that tuberculosis control among aboriginal people must be "achieved in a culturally sensitive manner with a greater degree of community partnership that has been seen in the past." With this in mind, we are currently collaborating with the Institute of Health Promotion at the University of British Columbia to develop a community-based trainer program to involve First Nations people in planning and implementing community-driven and community-based chemoprophylaxis programs. By involving community members as well as health care professionals, it is hoped that we will be able to achieve the aspiration that we all share: to reduce the unacceptable burden of tuberculosis among aboriginal people in Canada.