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To define the risks of disseminated bacille Calmette-Guérin (BCG) or disseminated Mycobacterium tuberculosis in adults with AIDS who were immunized with BCG in childhood.HIV-infected patients with CD4200 x 10(6)/l were enrolled from five study sites (New Hampshire, Boston, Finland, Trinidad and Kenya). Prior BCG immunization was determined and blood cultures for mycobacteria were obtained at study entry and at 6 months. Acid-fast bacilli were identified as Mycobacterium tuberculosis complex (MTBC) using DNA probes. MTBC isolates were then typed by both IS6110 restriction fragment length polymorphism and polymerase chain reaction/restriction enzyme analysis.Most patients in New Hampshire and Finland were outpatients; most patients in Trinidad were inpatients with terminal illness; and most patients in Kenya were outpatients, although 44 were inpatients with terminal illness.A total of 566 patients were enrolled, including 155 with childhood BCG immunization; 318 patients had a single study visit and culture, and 248 patients had two study visits and cultures.Isolation and identification of mycobacteria from blood cultures.Blood cultures were positive for MTBC in 21 patients; none were positive for M. bovis BCG, and 21 were M. tuberculosis-positive. In Trinidad, seven (87%) out of eight isolates of M. tuberculosis were indistinguishable by IS6110 typing; BCG immunization was associated with a decreased risk of bacteremic infection with M. tuberculosis (P = 0.05).The risk of disseminated BCG among adult AIDS patients with childhood BCG immunization is very low. Childhood BCG immunization is associated with protection against bacteremia with M. tuberculosis among adults with advanced AIDS in Trinidad.

To determine rates of disseminated Mycobacterium avium complex (MAC) infection among AIDS patients in developed and developing countries, and to determine whether different rates reflect differences in exposure or immunity, or both.Prospective cohort study.University hospitals and outpatient AIDS programs.HIV-infected subjects with CD4 counts200 x 10(6)/l were interviewed and had CD4 lymphocyte counts, blood cultures for mycobacteria (baseline and at 6 months), and skin tests with purified protein derivative (PPD) and M. avium sensitin.Among 566 study patients rates of disseminated MAC were 10.5-21.6% in New Hampshire, Boston and Finland compared to 2.4-2.6% in Trinidad and Kenya (P0.001). PPD skin test reactionsor = 5 mm were present in 20% of patients from Kenya compared to 1% at other sites (P0.001). Among patients from the United States and Finland, multiple logistic regression indicated that occupational exposure to soil and water was associated with a decreased risk of disseminated MAC, whereas the following were associated with an increased risk of disseminated MAC: low CD4 count, swimming in an indoor pool, history of bronchoscopy, regular consumption of raw or partially cooked fish/shellfish and treatment with granulocyte colony-stimulating factor.Rates of disseminated MAC in AIDS are higher in developed than developing countries and are due to both differences in exposure and differences in immunity. These data provide a rationale for prevention of MAC through both active immunization and reduction in exposure to the organism.