Divisions ofHIV/AIDS and ofBacterialand Mycotic Diseases. National

A case-control study was done to determine risk factors for Mycobacterium avium complex (MAC) disease in persons infected with human immunodeficiencyvirus (HIV) with <50 CD4+ cells/mm", In univariate analysis, cases (n = 83) had lower CD4+cell counts than controls (n = 177) (median, 10 vs. 17/mm3; P <.001) and were more likely to have consumed hard cheese (odds ratio [OR], 5.44; 95%confidenceinterval [CI], 1.61-18.4) but were less likelyto have taken daily showers (OR, 0.55; 95 % CI, 0.33-0.94). In multivariate analysis, CD4+ cell count <25/ mm! (OR, 3.58; 95 % CI, 1.71-7.49) and consumption of hard cheese (OR, 5.63; 95 % CI, 1.58-20.1) remained associated with disease, while daily showering (OR, 0.58; 95 % CI, 0.28-0.88) remained protective. Increased risk for MAC disease in persons with HIV infection and low CD4+ cell counts is not associated with exposure to water or a variety of other environmental sources but may be associated with consumption of hard cheese. Disease caused by organisms of the Mycobacterium avium complex (MAC) is the most common bacterial infection of patients with AIDS, occurring in 15%-24%ofpatients, and is associated with increased morbidity and shortened surviva