Tapering off of tuberculosis among the elderly.

Tuberculosis has long been prevalent among elderly people. When tubercle bacilli first enter human bodies they usually remain through the rest of their hosts' lives and are capable of causing clinical disease any time, even in old age. In 1900, a large percentage of people of all ages were harboring tubercle bacilli and high mortality and case rates obtained among elderly people. The only way to solve the problem among future old people was to protect infants, children, and youths from becoming infected and remain so throughout life. As far as possible that was accomplished by isolating and treating tuberculosis patients in sanatoriums and hospitals, with anti-tuberculosis drugs after 1946, and controlling the disease among cattle. In due time, large numbers of children entered adulthood uninfected. From year to year, they replaced those heavily infected as they advanced in years. By 1973 the mortality rate was only a fraction of 1.0 per 100,000 among people under 34 years but of those of 65 to 84 years it was 9.7. The case rate was 28.1 for those older than 45 years. Although tuberculosis among the elderly has tapered off phenomenally, much time and work are necessary to accomplish eradication.