Tuberculosis infection among young adults entering the US Navy in 1990

From 1958 through 1969, more than 1.2 million US Navy recruits received tuberculin skin tests; 5.2 per 100 were tuberculin reactors. Subsequent analyses predicted a downward trend in the risk of tuberculosis infection in the United States. We sought to determine the current prevalence of tuberculin reactors by sex, race/ethnic group, and birthplace among young adult residents of the United States entering the US Navy.

Recruits routinely receive a tuberculin skin test on entering US Navy recruit training in Great Lakes, Ill, Orlando, Fla, or San Diego, Calif. In January and February 1990, 2416 young men and women (mean age, 20.6 years) received tuberculin skin tests and completed questionnaires eliciting demographic and tuberculosis risk factor data. A tuberculin reactor was defined as a subject having 10 mm or greater induration to a skin test with 5 tuberculin units, purified protein derivative, administered intradermally by the Mantoux method.

Fifty-five of 2214 men (2.5 per 100; 95% confidence interval, 1.9 to 3.2 per 100) and five of 202 women (2.5 per 100; 95% confidence interval, 0.8 to 5.8 per 100) were tuberculin reactors. For men, the prevalence was greater in blacks (5.2 per 100), Hispanics (5.4 per 100), and Asian/Pacific Islanders (26.4 per 100) than in whites (0.8 per 100) and greater in foreign-born recruits (19.2 per 100) than in recruits born in the United States (1.6 per 100). Women had the same pattern of prevalence by race/ethnic group and birthplace.

The prevalence of tuberculosis reactors declined as predicted among young adults, especially the white US-born recruits, entering the US Navy. Although the prevalence also declined among nonwhites and the foreign-born recruits, a substantial proportion continue to enter adulthood with preexisting tuberculosis infection.