We noted with interest the prevalence projections by Douglas Schaubel and colleagues for end-stage renal disease in Canada to 2005 and their impact on health care utilization. [1] We would like to highlight an additional comorbid condition that will likely affect the management of these patients.
We recently established, for the first time on a population basis, the risk of tuberculosis (TB) among dialysis patients in British Columbia. [2] All cases of TB in British Columbia are reported to Tuberculosis Control, and specific risk factor for TB including dialysis are identified. Likewise, all individuals receiving dialysis are registered in a central registry. We compared the dialysis and TB registries for the study period and identified all confirmed active cases of TB. We determined that the risk of TB among the dialysis population is 25.3 (95% confidence interval 22.86-31.49, p < 0.001) times greater than that for a similar age-matched population.
This marked increase in the risk of active TB brings with it 2 important messages. Dialysis patients should be screened for the presence of tuberculous infection; although a significant proportion of patients many be anergic, many retain their ability to mount a response. [3] In the presence of a positive purified protein derivative (PPD) response, isoniazid chemoprophylaxis should be strongly considered. We recently reported the therapeutic option of twice weekly, directly observed chemoprophylaxis [4] and in the context of hemodialysis this represents an ideal way to ensure completion of therapy. Our finding should also alert physicians to the importance of considering TB in the presence of fever in their dialysis patients.
J. Mark FitzGerald, MD
R. Kevin Elwood, MB
S. Chia, MD
Tuberculosis Control; BC Centre for Disease Control Society; Vancouver, BC