[Tuberculosis in Israel--main epidemiological aspects]

Abstract

Background: In the last decade, tuberculosis (TB) has re-emerged as a major worldwide disease and also as a significant disease in Israel, particularly in the context of public health. In 1993, TB was declared a "global emergency" by the World Health Organization and in 1996, it was declared a "dangerous infectious disease" by the Israeli Ministry of Health.

Aim: This article aims to provide an epidemiological update on TB to the practicing physician in Israel. We present the perspective of the global situation together with relevant data on TB in Israel for use in clinical decision making.

Methods: All local data are from the ongoing epidemiological surveillance of TB conducted by the Department of Tuberculosis and AIDS in the Israeli Ministry of Health. Other data are cited from international sources.

Results: TB is greatly influenced by immigration (some 80-90% of TB cases are foreign-born and at least 65% are among new immigrants). Between 1989-1996 the incidence of TB by cohort analysis for year of immigration ranged from 38-172/100,000 (for new immigrants from the Former Soviet Union) to 500-3,000/100,000 (for new immigrants from Ethiopia). During this period incidence in the veteran population (Israeli-born and immigrants at least 5 years in the country) was, at the most. 4/100,000. Some 80% of TB cases were pulmonary. The rate of drug resistance is increasing some 20% of the isolated strains were resistant to at least one drug and some 8% were resistant to both Isoniazid and Rifampicin. (MDR, multi-drug-resistant). Tuberculosis associated with AIDS has increased in the last decade due to immigration from sub-Saharan Africa. Contrary to the belief existing in the general public, the number of TB cases among foreign workers was relatively low (7.6% of the cases reported in 1998).

Conclusion: In the clinical context, a practicing physician is most likely to diagnose TB in a recent immigrant. Thus since the symptoms of early TB are non-specific, diagnostic efforts (which are labor intensive and expensive) should be guided by a high index of suspicion in that particular population group. Furthermore, this epidemiological data provided the rationale for determining TB control policy as described in the second article on this subject.