FACTORS ASSOCIATED WITH TUBERCULIN REACTIVITY AMONG CHILDREN IN UNITED-ARAB-EMIRATES

A cross-sectional survey of tuberculin skin reactivity was conducted i n Al-Ain, United Arab Emirates (U.A.E.) between January and June 1994, to find out the prevalence rate of tuberculosis infection. A pre-desi gned questionnaire was used to collect details of BCG scar, age, sex, residence area, nationality, education, type of house, number of rooms , family size and household contact history of tuberculosis, A total o f 785 students were screened, of whom 547 gave a history of BCG vaccin ation in the past and 238 were BCG-negative. Among BCG-negative childr en aged 5-11 years and 12-15 years, only 6.5% and 9.3%, respectively, had a positive Mantoux reaction - a rate lower than most Third World c ountries, but higher than developed countries where under 2% of childr en are tuberculin reactors. A general linear model with positive Manto ux reaction as the dependent variable was fitted to the data to examin e the joint effect of age, sex, residential area, number of rooms at h ome, family size and BCG vaccine history. The Mantoux reaction was ent ered as positive and a number of statistically significant association s were found between positive Mantoux test >10 mm and: age (P=0.0018); sex (P=0.0281); residential area (P<0.0001); number of rooms (P=0.001 7); and BCG vaccine history (P<0.0001). However, family size did not h ave any statistical effect on tuberculin testing (Mantoux test >10 mm) . The prevalence (8%) in the 5-14 years age group puts U.A.E. between low (2%) and middle (14%) prevalence countries, according to the class ification of the International Union Against Tuberculosis. This calls for continuation of free treatment of active cases and increased effor ts towards screening of contacts.