TB among aboriginal Canadians
=============================

* Leo M. Kahana

The review by Mark FitzGerald and coworkers on the control of tuberculosis in aboriginal Canadians1 would have been improved by a brief reference to the history of the disease among these first Canadians. Tuberculosis was recognized in aboriginal North Americans in the pre-Columbian period but only became a major problem in the latter part of the 19th century, after we and the Americans had destroyed their livelihood, impoverished them and crowded them together on reservations or in prison (as we still do).2 Ferguson reported a mortality rate of 9000 per 100 000 in 1886, which is the highest rate ever recorded.3 For treatment we sent aboriginal people to fill the beds of sanatoria in southern Canada, where many died. When their families came to see what had happened to them, even their graves couldn't be located.

In view of the increased incidence of tuberculosis in aboriginal populations, it is natural to consider preventive methods. Bacillus Calmette-Guérin vaccine has been administered to more than 3 billion people, but there remains considerable doubt that it accomplishes anything. In controlled studies the protective efficacy varies from 57% to more than 75%, and it is not clear that averaging such disparate results by meta-analysis is of any significance.4 The efficacy is not, as the authors state, proven, and there is no reason to continue its wide use in aboriginal infants in contrast to the practice in the white population. Isoniazid prophylaxis in infected individuals is undoubtedly effective, but there has to be considerable caution in administering it to a population in which alcoholism and viral hepatitis are problems. The incidence of hepatotoxicity may be small, but the results can be catastrophic.[5, 6] A better alternative to isoniazid might be a combination of rifampin and levofloxacin, with a minimal risk of hepatitis.

The authors worry, perhaps patronizingly, about the risks of "health transfer" - allowing aboriginal people to take over responsibility for their own health needs. Our record, at least where tuberculosis is concerned, is dismal. The best solution would be to facilitate the transfer process and provide aboriginal people with their own clinics, nurses and doctors.

## References

1.  1. FitzGerald JM, Wang L, Elwood RK. Tuberculosis: 13. Control of the disease among aboriginal people in Canada. CMAJ 2000;162(3):351-5.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNjIvMy8zNTEiO3M6NDoiYXRvbSI7czoyNDoiL2NtYWovMTYyLzEwLzE0MDQuMS5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 

2.  2. Daniel TM, Bates JH, Downes KA. History of tuberculosis. In: Bloom BR, editor. *Tuberculosis: pathogenesis, protection, and control.* Washington: ASM Press; 1994. p. 13-24.
    
    

3.  3. Ferguson RG. *Studies in tuberculosis.* Toronto: University of Toronto Press; 1955. p. 6.
    
    

4.  4. Bloom BR, Fine PEM. The BCG experience: implications for future vaccines against tuberculosis. In: Bloom BR, editor. *Tuberculosis: pathogenesis, protection, and controls.* Washington: ASM Press; 1994. p. 531-57.
    
    

5.  5. Kahana LM. Hepatotoxicity of antituberculosis drugs [letter]. Thorax 1996;51:873.
    
    [FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6MzoiUERGIjtzOjExOiJqb3VybmFsQ29kZSI7czo5OiJ0aG9yYXhqbmwiO3M6NToicmVzaWQiO3M6MTA6IjUxLzgvODczLWIiO3M6NDoiYXRvbSI7czoyNDoiL2NtYWovMTYyLzEwLzE0MDQuMS5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 

6.  6. Mitchell L, Wendon J, Fitt S, Williams R. Anti-tuberculous therapy and acute liver failure. Lancet 1995;345:555-6.
    
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