Prevalence of tuberculosis in the western region of Saudi Arabia

الملخص EN

a sample survey in the Western region of Saudi Arabia was condueted to determine the prevalenee of tubereulosis infeetion by Man-toux testing.

A total of 1824 subjects were studied.

The prevalence of tuber-culin positivity (10 ءة mm) among subjects with no previous BCG vaccina-tion was found to be 9% in age group 5-14 years, putting this region midway between low (2%) and middle (14%) prevalence countries of the world.

This prevalence increased progressively with age to 5 ا % in age group 45-64 years, showing that a substantial pool of infected people exists who can break down into active disease and spread infection in the community.

It was higher among males than females, among urbans than rurals, and among non-Saudi than Saudi population.

BCG-induced tuberculin positiv-ity was found to wane in most cases; only 12°/o were Mantoux positive among BCG vaccinated subjects aged .14-؟ years, therefore, a positive Man-toux test in them can be taken as an indicator of infection by tubercle bacilli rather than due to BCG vaccination.

Marked increase in Mantoux positivity in age group 15-24 years (19 % in BCG negative, 30% in BCG positive sub-jects) suggests that revaccination with BCG at school leaving age may be useful in this population.