Tuberculosis surveillance in immigrants through health undertakings in Western Australia.

SETTING: Tuberculosis Control Program, Western Australia. OBJECTIVE: To assess the effectiveness and efficiency of tuberculosis (TB) surveillance in immigrants. DESIGN: Retrospective descriptive analysis of records of immigrants who first registered with the Tuberculosis Program from January 1994 to December 1995, having entered Western Australia on health undertakings (nonlegal contracts signed by those determined during premigration screening to require post-arrival evaluation). RESULTS: Of 1,344 immigrants on health undertakings for TB in the period, 587 (44%) had findings directly related to TB through pre-migration screening, 69 of whom required treatment for active disease. Another 443 (33%) had chest X-ray changes for which TB could not be excluded. Of the remaining 314 (23%), 172 had poor quality X-rays. Post-arrival assessment and follow-up of the whole group detected four of seven additional cases of active TB, 373 persons (28%) requiring on-going surveillance, 667 (50%) with non-TB conditions and 280 (21%) with normal chest X-rays. CONCLUSIONS: Migrant surveillance for TB in Australia is effective in detecting active disease and identifying a high-risk subgroup requiring further evaluation. Efficiency can be improved and high compliance achieved with simple administrative changes. Routine pre-migration Mantoux testing is inappropriate, and its inclusion in post-arrival assessments should be a national policy decision.

Preventive therapy for tuberculosis in Western Australia.

SETTING: State Tuberculosis Control Programme, Western Australia. OBJECTIVE: To ascertain baseline information, applicability and efficacy of preventive therapy for tuberculosis (TB) under indirectly supervised treatment in Western Australia. DESIGN: Retrospective analyses of records of persons with TB infection who were prescribed preventive therapy for the period 1993-1996 inclusive, using simple descriptive statistics. RESULTS: Preventive therapy was given to 411 persons after screening for TB due to on-arrival migrant surveillance (269), contact tracing (59), tuberculin surveys (59) and other reasons (24). Six-month isoniazid monotherapy (HMT) was prescribed for 403 and multidrug regimens for the remaining eight. Excepting 34 whose compliance was unknown, varying degrees of treatment non-adherence were found in 90 (24%) of the remaining 369 persons given HMT, including 36 (10%) with under five months of total medication. Minor adverse drug effects occurred in 32 (9%) subjects and contributed to the non-adherence in 23 of these. One person has since developed active TB. CONCLUSIONS: Preventive therapy in Western Australia conformed to generally accepted guidelines. Varying degrees of non-adherence to HMT occurred in 24% of persons, but 90% completed adequate therapy under indirect supervision. Non-adherence is significantly related to adverse drug effects.