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 firs t registered with the Tuberculosis Program from January 1994 to December 19 95, having entered Western Australia on health undertakings (nonlegal contr acts signed by those determined during premigration screening to require po st-arrival evaluation). RESULTS: Of 1344 immigrants on health undertakings for TB in the period, 58 7 (44%) had findings directly related to TB through pre-migration screening , 69 of whom required treatment for active disease. Another 443 (33%) had c hest 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 followup o f the whole group detected four of seven additional cases of active TB, 373 persons (28%) requiring ongoing surveillance, 667 (50%) with non-TB condit ions and 280 (21%) with normal chest X-rays. CONCLUSIONS: Migrant surveillance for TB in Australia is effective in detec ting active disease and identifying a high-risk subgroup requiring further evaluation. Efficiency can be improved and high compliance achieved with si mple administrative changes. Routine pre-migration Mantoux testing is inapp ropriate, and its inclusion in post-arrival assessments should be a nationa l policy decision.