Tuberculosis surveillance in immigrants to Manitoba

Despite a decrease in the incidence of tuberculosis in Canada over the last decade, the proportion of cases in people not born in Canada has increased. To determine the prevalence of active tuberculosis at the first surveillance clinic visit and the incidence of the disease over a 2-year to 6-year follow-up period, we reviewed the records of all 523 immigrants admitted to Manitoba between 1981 and 1985 who were placed under surveillance. Of the 523, 429 (82%) were seen at least once in the clinic. Among the 429, active tuberculosis was diagnosed at the first visit in 12 (3%) and during the follow-up period in 7 (2%). The relative risk of tuberculosis was 4.5 times higher for immigrants under surveillance than for those not under surveillance. Of the 483 immigrants who were to be seen in Winnipeg 232 (48%) were noncompliant: 94 were not seen at any time, and 138 did not attend for the full follow-up period. Active disease was not reported to have developed in any of the noncompliant subjects. Noncompliers were significantly older than compliers (p less than 0.005), and variations in compliance were noted according to region of origin. Further attempts to improve compliance with surveillance without resorting to punitive measures are indicated.