Systemic mycobacterioses in AIDS patients as determined by blood cultures on biphasic medium

Bacteremia due to mycobacteria can occur in AIDS patients in whom a rapid diagnosis is extremely important in order to plan a therapeutic conduct. Blood culture of mycobacteria using a biphasic system was set up in the Regional Laboratories of the Adolfo Lutz Institute, SP (Campinas, RibeirÒo Preto, Santo AndrÚ, Santos, SÒo JosÚ do Rio Preto and Sorocaba). During a three year period (1994-97), 1521 blood samples were analyzed from 1336 AIDS patients, with CD4+ cell count < 100/ml, hematocrit < 30 and serum albumin concentration < 3.0 g/dl seen in regional outpatient clinics or as inpatients in hospitals. Of the blood samples examined, 9.9 were positive for mycobacteria. The predominant species was Mycobacterium avium complex (MAC) (53.8) followed by Mycobacterium tuberculosis (28.0). Mycobacterium xenopi was isolated in one case (0.8) and in the remaining 17.4 the mycobacteria isolated were not identified. The implementation of blood culture for mycobacteria in our Institute has permitted the laboratory diagnosis of mycobacterial infections, in addition to providing data on the frequency of disseminated mycobacterial disease in AIDS patients in the region.

Bacteriological and epidemiological aspects of the diagnosis of Mycobacterium tuberculosis as the etiological agent of menigitis

Difficulties facing bacteriological diagnosis of meningitis are frequent, specially those caused by mycobacteria. From 1983 to 1987 samples of cerebrospinal fluid (CSF) from 16,921 patients mainly from the Emílio Ribas Hospital, SP, with clinical signs of meningitis were examined at the Instituto Adolfo Lutz, SP. 2,951 of the patients were diagnosed as being cases of bacterial meningitis, 134 of which tuberculous meningitis (4.5 per cent). 40.2 per cent were individuals of age 0-4 years, 52.3 per cent over 14 years and 7.5 per cent of unknown age. Tuberculous meningitis was clinically suspected in 51.5 per cent of the cases, while in the remaining cases (48.5 per cent) it was detected mainly because of the routine investigation of mycobacteria in CSF. Considering that the laboratory does not always receive a request to analyze M. tuberculosis in CSF and that, in terms of public health, tuberculosis is still an important problem, a careful study of mycobacteria in suspect cases of meningitis is recommended.