The impact of HIV infection on Mycobacterium kansasii disease in South African gold miners.

The impact of human immunodeficiency virus (HIV) infection on Mycobacterium kansasii disease in miners was investigated with a retrospective study cov ering a single workforce. M. kansasii, isolated from 43 HIV-positive and 20 2 HIV-negative miners, was the most common nontuberculous mycobacterial (NT M) species in both HIV groups. CD4 counts were unusually high for M. kansas ii disease (mean 490 x 10(6)/L, from 14 HIV-positive men). Treatment outcom es were similar: mortality during treatment was higher in HIV-positive than in HIV-negative men (9% and 2%, respectively), but not significantly so. T he majority of a sample of 31 HIV-positive and 92 HIV-negative men had radi ological silicosis and/or old tuberculosis scarring prior to M. kansasii di sease. A normal premorbid radiograph was more common in HIV-positive men (4 5% versus 24%; odds ratio [OR], 2.62; 95% confidence interval [95% CI], 1.0 1 to 6.67). New cavitation was less common (55% versus 78%; OR, 0.34; 95% C I, 0.13 to 0.88) and new hilar adenopathy more common (OR, 5.07; 95% CI, 1. 24 to 21.9) in HIV-positive than in HIV-negative men. Miners, who have addi tional NTM risk factors, develop M. kansasii disease that occurs at an earl ier stage of HIV infection and more closely resembles disease in HIV-negati ve men than has been found for HIV-associated M. kansasii disease in other settings.