Tuberculin sensitivity trends in Hellenic army recruits during the period 1981-91

Abstract

Setting: The tuberculin skin test is widely used to define the tuberculous infection in the community. Serial representative tuberculin surveys demonstrate the trend of the risk of tuberculous infection. Objective: The study of tuberculous infection in Hellenic army recruits for the purposes of BCG vaccination, which with chemoprophylaxis and early case-finding are the major strategies used for preventing tuberculosis (TB). Design: We investigated tuberculin skin sensitivity on 544210 Hellenic Armed Forces recruits during 1981–1991. The age of the subjects ranged between 18–28 years (mean 21 ± 1.5 years). We used the Mantoux technique with tuberculin PPD-RT 23 with Tween 80, dose 2 IU ( 1 5000 ) of the Hellenic Pasteur Institute. Tuberculin skin reactions were examined by two experienced readers after 48 hours. Indurations < 5 mm were considered as negative reactions, ≥ 10 mm as positive, and 5–9 mm as doubtful reactions. Results: The results of the present study were compared to other studies undertaken in recruits during the period 1934-80. We found a decrease of positive reactions from 14.2% in 1981 to 6.8% in 1991. The mean annual reduction was 0.74%. The decline has continued since 1947, as previous studies during the period 1934-80 have shown. Conclusion: We conclude that the tuberculin reactivity in recruits of the Hellenic army, although still high in relation to other European countries and North America, is declining steadily. We predict that the number of positive reactions will fall to about 1 % by the year 2000, assuming that the same trend continues.