Some studies have found that health care workers have an increased risk of tuberculosis, whereas other studies have reported the opposite. This study examined data of Finnish health care workers (HCWs) for the incidence of tuberculosis disease. Cases of occupational tuberculosis in Finland were analysed over a period of 30 yrs (1966-1995). Control subjects were all other incident tuberculosis cases at working age. The material thus obtained included 658 people with notified occupational tuberculosis, and 56,146 control cases. The authors studied incidence, and age specific rate, as well as their trends. The incidence of tuberculosis among health care workers decreased from 57.9 to 6.1 per 100,000 and the corresponding figures among control subjects decreased from 156.8 to 9.1 per 100,000. The overall risk in health care workers was lower than in the general population throughout the study period. Analysis of age specific rates revealed no age group at increased risk. The reasons are multifactorial, among them the successful tuberculosis programme, and the lack of impact of such risk factors as immigration, human immunodeficiency virus infection and drug resistance; high coverage of bacille Calmette-Guérin vaccination may also be a factor, although it is difficult to assess.
The incidence of tuberculosis in the Nordic countries is one of the lowest in the world: Denmark 5.1, Iceland 6.4, Norway 6.9 and Sweden 6.5; whereas in Finland it is around the mean for Europe, 28.9 per 100,000 (1988). The immigrants are the risk group because they usually come from countries with a high prevalence. The BCG-vaccination at birth is still used in Finland. Other Nordic countries vaccinate mainly the risk groups. Revaccination is no longer indicated. After the discontinuation of the BCG at birth in 1975 the sensitivity to environmental mycobacteria has increased in Sweden. The screening programmes have been phased out but there is reason to take tuberculosis into account at pre-employment examinations, and to perform meticulous contract tracing of the smear-positives. Effective short course chemotherapy is given in all the countries. The Nordic countries must continue to keep accurate tuberculosis registers, to maintain the high diagnostic level and successfully apply the latest high technology and know-how for the eradication of tuberculosis which, however, will persist into the next generation.