title: Differential tuberculin testing in rural populations in Ceylon.
mesh_terms: D000293:Adolescent; D000328:Adult; D000531:Altitude; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D009164:Mycobacterium Infections / Q000276:immunology; D044469:Racial Groups; D012737:Sex Factors; D013188:Sri Lanka; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000276:immunology