title: Interpretation of positive reactions to Heaf tuberculin test in London schoolchildren.
abstract: A study of 289 children aged 12-14 years found to be Heaf test positive at routine testing was made to determine the likely cause of the positive tests. Only 12% of children grade 1 Heaf positive were likely to have had a previous infection with Mycobacterium tuberculosis, 49% were likely to have had infections with atypical mycobacteria, and in 39% no cause for the positive Heaf test was found.The positive Heaf test seems to us to be too sensitive. Both a negative and grade 1 positive should be regarded as not significant and these children given B.C.G. vaccine. Heaf grades 2, 3, and 4 should be regarded as significant and the children investigated for M. tuberculosis infection.
mesh_terms: D000293:Adolescent; D001500:BCG Vaccine; D002648:Child; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D006801:Humans; D008131:London; D008403:Mass Screening; D008722:Methods; D009164:Mycobacterium Infections / Q000175:diagnosis; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D014373:Tuberculin / Q000494:pharmacology; D014374:Tuberculin Test
chemical_list: D001500:BCG Vaccine; D014373:Tuberculin