ABSTRACT
SETTING: New South Wales (NSW) is Australia's most populous state and is home to one third of the country's rapidly growing immigrant population. OBJECTIVE: To examine the effects of immigration upon the epidemiology of tuberculosis (TB) in a low prevalence population. DESIGN: A retrospective review of state TB surveillance data in NSW from 1975-1995. RESULTS: The crude notification rate for all active TB declined from 12.2 per 100000 population in 1975 to 5.2/100000 in 1986, after which the notification rate increased steadily to 7.6/100000 in 1995. Between 1975 and 1995, the proportion of all TB notifications occurring in overseas-born residents increased from 30% (178/601) to 79% (345/435). During this period, the proportion of new extra-pulmonary TB notifications increased from 13% (72/549) to 42% (171/405). Notifications amongst women increased from 31% (188/601) to 47% (218/462) of the total, while the median age at notification fell from 55 to 41 years. The pattern of TB disease has not changed for Australian-born cases, who are mostly elderly men with pulmonary disease. Multidrug-resistant TB remains uncommon (<1%), and co-infection with the human immunodeficiency virus (HIV) and TB has not emerged as a major problem (2% of notifications), but is poorly documented. CONCLUSION: TB has re-emerged in NSW predominantly because of increased immigration from high prevalence countries. The epidemiology of TB has become dominated by overseas-born notifications, and now younger adults are primarily affected. Enhancing the effectiveness of the TB screening procedures for immigrants is a priority. Information should be provided to all immigrants and to long-term visitors from countries of high TB prevalence regarding TB infection and the TB services available in Australia.
