[Mycobacterium avium complex infection: a growing problem in our country]. / Infección por Mycobacterium avium cómplex: un problema creciente en nuestro entorno.

Since the emergence of AIDS, disseminated Mycobacterium avium complex (MAC) infection has become a growing cause of morbidity and mortality in this group of patients. Our objective was to study the incidence and the clinical and microbiological features of MAC infection in HIV-positive patients as well as the response to a therapy regimen combining clarithromycin and ethambutol. At our hospital, the first patient with disseminated MAC infection was diagnosed in 1988. Since then, 54 HIV-positive patients with MAC infection have been diagnosed (30/1,000 HIV-positive patients). MAC represented 12% of recovered mycobacteria in HIV-positive patients and this percentage has increased from 3.9% in 1988 to 16.4% in 1994. All episodes of MAC infection occurred in patients with advanced HIV diseases (mean CD4: 73/microliter). MAC infection was the disease diagnosing AIDS in 23.4% of cases. The most common clinical manifestations included fever (85.7%), weight loss (55%), and pulmonary involvement (50%). A total of 55 specimens were processed for mycobacterial culture from 54 patients (mean of 10.2 specimens per patient). A total of 122 were positive (21.9%: 2.25 positive specimens per patient). The specimens with the greater percentage of positive results were bone marrow aspirates (65.3%) and blood cultures (47.7%), followed by respiratory (16.5%) and urine specimens (5.3%). Regarding therapy, sixteen of the 54 investigated patients did not receive specific drugs for MAC infection, 7 were treated with different combinations of active drugs against MAC (rifampin, clofazimine, amikacin, ethambutol, and isoniazid) and 31 received a combination of clarythromicin (1 g/12 hourly) and ethambutol (400 mg/12 hourly). Seventy-four percent of patients treated with clarythromicin and ethambutol improved clinically, and the mean survival time in these patients (253 days) was significantly longer than that in not treated patients (p < 0.05). No significant differences were noted in survival time between the group of patients treated with clarythromicin and ethambutol and that with other drug combinations. The incidence of disseminated MAC infection in our environment is increasing in patients with advanced HIV disease. The combination of clarythromicin plus ethambutol was well tolerated and efficient for the treatment of disseminated MAC infection.

Fever of uncertain origin in patients infected with the human immunodeficiency virus.

To assess the frequency and etiology of fever of uncertain origin (FUO) in patients infected with the human immunodeficiency virus (HIV) and to evaluate the yield of diagnostic procedures used in their evaluation, we reviewed the clinical charts of all patients admitted to an AIDS unit during a 15-month period. FUO was defined by the endurance of a fever (temperature, > 38.2 degrees C) for at least 4 weeks before admission and the uncertainty of diagnosis after 3 days, despite appropriate investigation. Of 580 patients evaluated, 50 (8.2%) had FUO. Patients with FUO were at advanced stages of HIV infection (median CD4+ cell count, 71/mm3), and a vast majority (84%) had previously diagnosed AIDS. A cause of the fever was identified for 44 patients (88%), and infections accounted for 82% of all cases. Tuberculosis (42%), visceral leishmaniasis (14%), and disseminated Mycobacterium avium complex infection (14%) were the most frequent diagnoses. Examination of lymph node aspirates, bone marrow biopsy, and culture of clinical specimens for mycobacteria were the procedures with the highest diagnostic yield. Among 6 patients with fever of no identified etiology, 4 died while febrile, and fever was self-limited in the other 2 patients. FUO is common among patients with advanced HIV infection. Since a cause, usually infection, can be identified in most patients, long-lasting fever should not be attributed to HIV itself.

Risk for developing tuberculosis among anergic patients infected with HIV.

OBJECTIVE: To assess the risk for development of tuberculosis among anergic patients infected with the human immunodeficiency virus (HIV). DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: All HIV-infected patients who had a baseline positive protein purified derivative test (PPD) and delayed-type hypersensitivity skin tests. MEASUREMENTS: Development of active tuberculosis. RESULTS: Of 374 patients, 108 (29%) had positive results of PPD tests, 154 (41%) had negative results of PPD tests but no skin anergy, and 112 (30%) were anergic. Conversion of the PPD to positive was observed in 10 of 67 (15%) patients with previously negative results of PPD tests and no anergy and in 3 of 36 (8%) anergic patients who were retested during the follow-up period (mean, 26 months). The risk for active tuberculosis to develop in patients not receiving isoniazid chemoprophylaxis was similar in patients with a positive PPD test result (10.4 cases per 100 person-years) and in anergic patients (12.4 cases per 100 person-years) and higher in both groups than in nonanergic patients with a negative PPD test result (5.4 cases per 100 person-years). Tuberculosis was more frequent among intravenous drug abusers with no previous isoniazid treatment (63 of 290, 22%) than among homosexual men (0 of 29) or patients in other HIV transmission categories (0 of 31). Preventive therapy with isoniazid reduced tuberculosis development (4% as compared with 31%; P = 0.008). Among 15 anergic patients who had CD4 counts measured within 3 months of tuberculosis development, only 1 (7%) had more than 500 CD4 cells/mm3. CONCLUSIONS: Anergic HIV-infected patients are at high risk for development of tuberculosis. Anergic HIV-infected patients, in addition to HIV-infected patients with positive results of PPD tests, should be offered preventive therapy if they live in areas with a high prevalence of tuberculosis, at least when the CD4 count decreases to less than 500 CD4 cells/mm3.