[Skip to Content]
[Skip to Content Landing]
Sept 18, 1967

Tuberculin Conversion

Author Affiliations

Durham, NC

JAMA. 1967;201(12):981. doi:10.1001/jama.1967.03130120089033

This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.


To the Editor:—  I have read with great interest Dr. Ochs' report on tuberculin conversions in naval personnel on board the USS Long Beach in 1962 and 1963 (200:1019, 1967).It is obvious from Dr. Ochs' article that he was disturbed to find that 9% of approximately 1,000 crew members converted from a negative reaction to the 5-TU, intermediate dose of PPD ( 0.0001 mg), to a positive reaction to the same dose, when the tests were repeated later. A conversion rate of 9% per annum was indeed shocking when he was expecting an annual conversion rate of one fourth of 1%. Furthermore, no symptoms of disease developed in any of these converters, and physical examination and x-ray studies showed no evidence of disease.Dr. Ochs suggests, "The conversions may have been related to 'naturally occurring' atypical mycobacteria in the geographic area. The ship was berthed at the ports of