Epidemic of pulmonary tuberculosis in geriatric homes.

The prevalence of pulmonary tuberculosis in 809 residents of 11 old-age homes for whites and 1 for coloureds in East London, CP, was investigated in a cross-sectional study. A Mantoux test, chest radiography, an enzyme-linked immunosorbent assay (ELISA) and sputum culture were used. The diagnosis was made on sputum culture in 12 subjects. The Mantoux test was positive in 7 of these subjects, and in 25% of the population. The ELISA on adsorbed sonicated mycobacterial antigen had a positive predictive value of 13% and probably has no diagnostic value for tubercular disease in this population. Of the subjects with a positive diagnosis 1 had a normal chest radiograph; 10 had minimal basal inflammatory infiltrates or patchy fibrotic changes, and 1 had evidence of classic reactivation of old apical lesions. The national incidence of tuberculosis in the low-risk white population is 16/100,000. In old-age homes for whites, however, the overall case rate was 798/100,000 (a 50-fold increase), and in one home where there was a cluster of cases, it was 6,849/100,000. In the home for coloureds the prevalence was 10,344/100,000. This confirms other studies showing that elderly people living in old-age homes are at particular risk of developing tuberculosis. Males appear to be at higher risk than females. Recommendations regarding the diagnosis and control of tuberculosis in the elderly in institutions and in old-age homes are made.