Intensity of exposure to pulmonary tuberculosis determines risk of tuberculosis infection and disease.

Household contacts of pulmonary tuberculosis (TB) patients are at increased risk of TB infection and disease. However, their risk in relation to the intensity of exposure remains unknown.We studied smear-positive TB cases and their household contacts in Vitória, Brazil. We collected clinical, demographic and radiographic information from TB cases, and obtained tuberculin skin test (TST) and QuantiFERON-TB Gold (QFT) results from household contacts. We measured intensity of exposure using a proximity score and sleep location in relation to the TB index case and defined infection by TST ≥10 mm or QFT ≥0.35 UI·mL-1 We ascertained secondary TB cases by reviewing local and nationwide case registries.We included 160 TB index cases and 894 household contacts. 464 (65%) had TB infection and 23 (2.6%) developed TB disease. Risk of TB infection and disease increased with more intense exposures. In an adjusted analysis, the proximity score was associated with TB disease (OR 1.61, 95% CI 1.25-2.08; p<0.000); however, its diagnostic performance was only moderate.Intensity of exposure increased risk of TB infection and disease among household contacts; however, its diagnostic performance was still suboptimal. A biomarker to target preventive therapy is urgently needed in this at-risk population.

Incident Mycobacterium tuberculosis infection in household contacts of infectious tuberculosis patients in Brazil.

BACKGROUND: In household contact investigations of tuberculosis (TB), a second tuberculin skin test (TST) obtained several weeks after a first negative result consistently identifies individuals that undergo TST conversion. It remains unclear whether this delay in M. tuberculosis infection is related to differences in the infectious exposure, TST boosting, partial host resistance, or some other factor. METHODS: We conducted a household contact study Vitória, Brazil. Between 2008 and 2013, we identified culture-positive pulmonary TB patients and evaluated their household contacts with both a TST and interferon gamma release assay (IGRA), and identified TST converters at 8-12 weeks post study enrollment. Contacts were classified as TST-positive (≥10 mm) at baseline, TST converters, or persistently TST-negative. We compared TST converters to TST-positive and to TST-negative contacts separately, using generalized estimating equations. RESULTS: We enrolled 160 index patients and 838 contacts; 523 (62.4%) were TST+, 62 (7.4%) TST converters, and 253 (30.2%) TST-. TST converters were frequently IGRA- at 8-12 weeks. In adjusted analyses, characteristics distinguishing TST converters from TST+ contacts (no contact with another TB patient and residence ownership) were different than those differentiating them from TST- contacts (stronger cough in index patient and contact BCG scar). CONCLUSIONS: The individual risk and timing of M. tuberculosis infection within households is variable and dependent on index patient, contact and environmental factors within the household, and the surrounding community. Our findings suggest a threshold effect in the risk of infection in humans.

Analytical and Clinical Evaluation of the Epistem Genedrive Assay for Detection of Mycobacterium tuberculosis.

The Epistem Genedrive assay rapidly detects the Mycobacterium tuberculosis omplex from sputum and is currently available for clinical use. However, the analytical and clinical performance of this test has not been fully evaluated. The analytical limit of detection (LOD) of the Genedrive PCR amplification was tested with genomic DNA; the performance of the complete (sample processing plus amplification) system was tested by spiking M. tuberculosismc(2)6030 cells into distilled water andM. tuberculosis-negative sputum. Specificity was tested using common respiratory pathogens and nontuberculosis mycobacteria. A clinical evaluation enrolled adults with suspected pulmonary tuberculosis, obtained three sputum samples from each participant, and compared the accuracy of the Gene drive to that of the Xpert MTB/RIF assay using M. tuberculosiscultures as the reference standard. The Genedrive assay had an LOD of 1 pg/µl (100 genomic DNA copies/reaction). The LODs of the system were 2.5 × 10(4)CFU/ml and 2.5 × 10(5)CFU/ml for cells spiked into water and sputum, respectively. False-positiverpoBprobe signals were observed in 3/32 (9.4%) of the negative controls and also in few samples containing Mycobacterium abscessus,Mycobacterium gordonae, o rMycobacterium thermoresistibile In the clinical study, among 336 analyzed participants, the overall sensitivities for the tuberculosis case detection of Gene drive, Xpert, and smear microscopy were 45.4% (95% confidence interval [CI], 35.2% to 55.8%), 91.8% (95% CI, 84.4% to 96.4%), and 77.3% (95% CI, 67.7% to 85.2%), respectively. The sensitivities of Gene drive and Xpert for the detection of smear-microscopy-negative tuberculosis were 0% (95% CI, 0% to 15.4%) and 68.2% (95% CI, 45.1% to 86.1%), respectively. The Genedrive assay did not meet performance standards recommended by the World Health Organization for a smear microscopy replacement tuberculosis test. Epistem is working on modifications to improve the assay.

Nosocomial rapidly growing mycobacterial infections following laparoscopic surgery: CT imaging findings.

OBJECTIVE: To identify the distribution and frequency of computed tomography (CT) findings in patients with nosocomial rapidly growing mycobacterial (RGM) infection after laparoscopic surgery. METHOD: A descriptive retrospective study in patients with RGM infection after laparoscopic surgery who underwent CT imaging prior to initiation of therapy. The images were analyzed by two radiologists in consensus, who evaluated the skin/subcutaneous tissues, the abdominal wall, and intraperitoneal region separately. The patterns of involvement were tabulated as: densification, collections, nodules (≥1.0 cm), small nodules (<1.0 cm), pseudocavitated nodules, and small pseudocavitated nodules. RESULTS: Twenty-six patients met the established criteria. The subcutaneous findings were: densification (88.5%), small nodules (61.5%), small pseudocavitated nodules (23.1 %), nodules (38.5%), pseudocavitated nodules (15.4%), and collections (26.9%). The findings in the abdominal wall were: densification (61.5%), pseudocavitated nodules (3.8%), and collections (15.4%). The intraperitoneal findings were: densification (46.1%), small nodules (42.3%), nodules (15.4%), and collections (11.5%). CONCLUSION: Subcutaneous CT findings in descending order of frequency were: densification, small nodules, nodules, small pseudocavitated nodules, pseudocavitated nodules, and collections. The musculo-fascial plane CT findings were: densification, collections, and pseudocavitated nodules. The intraperitoneal CT findings were: densification, small nodules, nodules, and collections. KEY POINTS: • Rapidly growing mycobacterial infection may occur following laparoscopy. • Post-laparoscopy mycobacterial infection CT findings are densification, collection, and nodules. • Rapidly growing mycobacterial infection following laparoscopy may involve the peritoneal cavity. • Post-laparoscopy rapidly growing mycobacterial intraperitoneal infection is not associated with ascites or lymphadenopathy.

Multilocus sequence typing scheme versus pulsed-field gel electrophoresis for typing Mycobacterium abscessus isolates.

Outbreaks of infections by rapidly growing mycobacteria following invasive procedures, such as ophthalmological, laparoscopic, arthroscopic, plastic, and cardiac surgeries, mesotherapy, and vaccination, have been detected in Brazil since 1998. Members of the Mycobacterium chelonae-Mycobacterium abscessus group have caused most of these outbreaks. As part of an epidemiological investigation, the isolates were typed by pulsed-field gel electrophoresis (PFGE). In this project, we performed a large-scale comparison of PFGE profiles with the results of a recently developed multilocus sequence typing (MLST) scheme for M. abscessus. Ninety-three isolates were analyzed, with 40 M. abscessus subsp. abscessus isolates, 47 M. abscessus subsp. bolletii isolates, and six isolates with no assigned subspecies. Forty-five isolates were obtained during five outbreaks, and 48 were sporadic isolates that were not associated with outbreaks. For MLST, seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH) were sequenced, and each isolate was assigned a sequence type (ST) from the combination of obtained alleles. The PFGE patterns of DraI-digested DNA were compared with the MLST results. All isolates were analyzable by both methods. Isolates from monoclonal outbreaks showed unique STs and indistinguishable or very similar PFGE patterns. Thirty-three STs and 49 unique PFGE patterns were identified among the 93 isolates. The Simpson's index of diversity values for MLST and PFGE were 0.69 and 0.93, respectively, for M. abscessus subsp. abscessus and 0.96 and 0.97, respectively, for M. abscessus subsp. bolletii. In conclusion, the MLST scheme showed 100% typeability and grouped monoclonal outbreak isolates in agreement with PFGE, but it was less discriminative than PFGE for M. abscessus.

Gnathostoma infection after ingestion of raw fish is a probable cause of eosinophilic meningitis in the Brazilian Amazon.

We report a case of eosinophilic meningitis associated with the ingestion of raw fish (Cichla sp.) from the Brazilian Amazon, likely caused by Gnathostoma. A 36-year-old male visited Juruena river on a fishing trip. After 50 days, the patient presented with an intense frontal headache. A cerebrospinal fluid examination revealed 63% eosinophilia. Another individual who ingested raw fish developed linear dermatitis on the abdominal wall. Anti-Gnathostoma serum antibodies were detected, and the patient made a full recovery after treatment with corticosteroids and albendazole. To date, autochthonous Gnathostoma spp. infections in Latin American countries have only caused linear panniculitis. This report raises awareness of gnathostomiasis-causing meningitis.

The small membrane filter method of microscopy to diagnose pulmonary tuberculosis.

We modified microscopy for acid-fast bacilli to diagnose tuberculosis (TB) using small membrane filters (SMFs) after special processing and prefiltration. With the first specimen obtained from each of 335 persons suspected of having TB, the sensitivity of the new SMF method using fluorescence microscopy (FM) was 89% (95% confidence interval [CI]: 80%, 95%). This was significantly better (P = 0.0001) than the sensitivity of routine FM of centrifuged specimens of 60% (95% CI: 49%, 71%) or that of direct sputum smears of 56% (95% CI: 40%, 72%).

Evaluation of processing methods to equitably aliquot sputa for mycobacterial testing.

We compared bacillary loads after splitting sputum specimens by chemical (N-acetyl-l-cysteine [NALC]) and mechanical homogenization by vortexing with sterile glass beads. NALC and vortexing with glass beads were equally effective at homogenizing sputum specimens, resulting in an equal distribution of tubercle bacilli in the aliquots.

Increase of CD4+CD25highFoxP3+ cells impairs in vitro human microbicidal activity against Mycobacterium tuberculosis during latent and acute pulmonary tuberculosis.

BACKGROUND: Regulatory T cells (Tregs) play a critical role during Mycobacterium tuberculosis (Mtb) infection, modulating host responses while neutralizing excessive inflammation. However, their impact on regulating host protective immunity is not completely understood. Here, we demonstrate that Treg cells abrogate the in vitro microbicidal activity against Mtb. METHODS: We evaluated the in vitro microbicidal activity of peripheral blood mononuclear cells (PBMCs) from patients with active tuberculosis (TB), individuals with latent tuberculosis infection (LTBI, TST+/IGRA+) and healthy control (HC, TST-/IGRA-) volunteers. PBMCs, depleted or not of CD4+CD25+ T-cells, were analyzed to determine frequency and influence on microbicidal activity during in vitro Mtb infection with four clinical isolates (S1, S5, R3, and R6) and one reference strain (H37Rv). RESULTS: The frequency of CD4+CD25highFoxP3+ cells were significantly higher in Mtb infected whole blood cultures from both TB patients and LTBI individuals when compared to HC. Data from CD4+CD25+ T-cells depletion demonstrate that increase of CD4+CD25highFoxP3+ is associated with an impairment of Th-1 responses and a diminished in vitro microbicidal activity of LTBI and TB groups. CONCLUSIONS: Tregs restrict host anti-mycobacterial immunity during active disease and latent infection and thereby may contribute to both disease progression and pathogen persistence.

Shortening treatment in adults with noncavitary tuberculosis and 2-month culture conversion.

RATIONALE: Cavitary disease and delayed culture conversion have been associated with relapse. Combining patient characteristics and measures of bacteriologic response might allow treatment shortening with current drugs in some patients. OBJECTIVES: To assess whether treatment could be shortened from 6 to 4 months in patients with noncavitary tuberculosis whose sputum cultures converted to negative after 2 months. METHODS: This study was a randomized, open-label equivalence trial. HIV-uninfected adults with noncavitary tuberculosis were treated daily with isoniazid, rifampin, pyrazinamide, and ethambutol for 2 months, followed by 2 months of isoniazid and rifampin. After 4 months, patients with drug-susceptible TB whose sputum cultures on solid media were negative after 8 weeks of treatment were randomly assigned to continue treatment for 2 more months or to stop treatment. Patients were followed for relapse for 30 months after beginning treatment. MEASUREMENTS AND MAIN RESULTS: Enrollment was stopped by the safety monitoring committee after 394 patients were enrolled due to apparent increased risk for relapse in the 4-month arm. A total of 370 patients were eligible for per protocol analysis. Thirteen patients in the 4-month arm relapsed, compared with three subjects in the 6-month arm (7.0 vs. 1.6%; risk difference, 0.054; 95% confidence interval with Hauck-Anderson correction, 0.01-0.10). CONCLUSION: Shortening treatment from 6 to 4 months in adults with noncavitary disease and culture conversion after 2 months using current drugs resulted in a greater relapse rate. The combination of noncavitary disease and 2-month culture conversion was insufficient to identify patients with decreased risk for relapse.

Differentially culturable tubercle bacteria dynamics during standard anti-tuberculosis treatment: A prospective cohort study.

This study aimed to evaluate the dynamics of culture filtrate dependent subpopulations of Mycobacterium tuberculosis in a prospective cohort study following 17 patients through a standard 6-month anti-tuberculosis regimen, performing monthly sputum collection. We performed the limiting dilution method with culture filtrate supplementation of liquid media in pre- and post-treatment sputum samples to assess the bacillary load and to evaluate the Mycobacterium tuberculosis subpopulation dynamics within the 6-months standard anti-tuberculosis regimen. We found that supplementation increased the bacillary load by 30% in pre-treatment samples (p = 0.0005) and 35% in samples after one month of treatment (p = 0.0977). We found a weak linear correlation between the decrease of Mycobacterium tuberculosis growth in liquid media with and without culture filtrate supplementation (ρ = 0.54; p = 0.026). None of the patients had bacilli recovery after two months of treatment. Our study constitutes the first follow-up regarding Mycobacterium tuberculosis subpopulation dynamics throughout a standard 6-month anti-tuberculosis treatment and also supports the use of culture filtrate to increase bacillary load in liquid media. Moreover, it highlights that any new treatment regimens should test the efficacy of the drugs in all Mycobacterium tuberculosis subpopulations.

Population pharmacokinetics of linezolid in adults with pulmonary tuberculosis.

Nineteen adults with pulmonary tuberculosis received linezolid (600 mg) once or twice daily in an early bactericidal activity trial. A one-compartment population model produced median values for the absorption rate constant, volume of distribution, and elimination rate constant of 1.5 h(-1), 29.6 liters, and 0.25 h(-1) (once daily) and 2.7 h(-1), 32.1 liters, and 0.15 h(-1) (twice daily). Linezolid administered twice daily produced higher values for free drug area under the concentration-time curve (AUC)/MIC and time above MIC. Both regimens achieved free AUC/MIC ratios > 100. Median times above the MIC for free drug were 100% (twice daily) and 63% (once daily).

Early and extended early bactericidal activity of linezolid in pulmonary tuberculosis.

RATIONALE: Linezolid, the first oxazolidinone approved for clinical use, has effective in vitro and promising in vivo activity against Mycobacterium tuberculosis. OBJECTIVES: To evaluate the early and extended early bactericidal activity of linezolid in patients with pulmonary tuberculosis. METHODS: Randomized open label trial. Thirty patients with newly diagnosed smear-positive pulmonary tuberculosis (10 per arm) were assigned to receive isoniazid (300 mg daily) and linezolid (600 mg twice daily or 600 mg once daily) for 7 days. Sputum for quantitative culture was collected for 2 days before and then daily during 7 days of study drug administration. Bactericidal activity was estimated by measuring the decline in bacilli during the first 2 days (early bactericidal activity) and the last 5 days of study drug administration (extended early bactericidal activity). MEASUREMENTS AND MAIN RESULTS: The mean early bactericidal activity of isoniazid (0.67 log10 cfu/ml/d) was greater than that of linezolid twice and once daily (0.26 and 0.18 log10 cfu/ml/d, respectively). The extended early bactericidal activity of linezolid between Days 2 and 7 was minimal. CONCLUSIONS: Linezolid has modest early bactericidal activity against rapidly dividing tubercle bacilli in patients with cavitary pulmonary tuberculosis during the first 2 days of administration, but little extended early bactericidal activity. Clinical trial registered with www.clinicaltrials.gov (NCT00396084).

Gnathostoma infection after ingestion of raw fish is a probable cause of eosinophilic meningitis in the Brazilian Amazon

ABSTRACT We report a case of eosinophilic meningitis associated with the ingestion of raw fish (Cichla sp.) from the Brazilian Amazon, likely caused by Gnathostoma. A 36-year-old male visited Juruena river on a fishing trip. After 50 days, the patient presented with an intense frontal headache. A cerebrospinal fluid examination revealed 63% eosinophilia. Another individual who ingested raw fish developed linear dermatitis on the abdominal wall. Anti-Gnathostoma serum antibodies were detected, and the patient made a full recovery after treatment with corticosteroids and albendazole. To date, autochthonous Gnathostoma spp. infections in Latin American countries have only caused linear panniculitis. This report raises awareness of gnathostomiasis-causing meningitis.

Use of in-house PCR for identification of Mycobacterium tuberculosis in BACTEC broth cultures of respiratory specimens.

We evaluated the ability of a PCR assay to identify Mycobacterium tuberculosis complex (MTBC) from positive BACTEC 12B broth cultures. A total of 107 sputum samples were processed and inoculated into Ogawa slants and BACTEC 12B vials. At a growth index (GI) > or=30, 1.0 ml of the 12B broth was removed, stored, and assayed with PCR. Molecular results were compared to those obtained by phenotypic identification methods, including the BACTEC NAP method. The average times required to perform PCR and NAP were compared. Of the 107 broth cultures evaluated, 90 were NAP positive, while 91 were PCR positive for MTBC. Of particular interest were three contaminated BACTEC 12B broth cultures yielding microorganisms other than acid-fast bacilli growth with a MTBC that were successfully identified by PCR, resulting in a mean time of 14 days to identify MTBC before NAP identification. These results suggest that PCR could be used as an alternative to the NAP test for the rapid identification of MTBC in BACTEC 12B cultures, particularly in those that contained both MTBC and nontuberculous mycobacteria.

[Evaluation of a scoring system recommended by the Brazilian Ministry of Health for the diagnosis of childhood tuberculosis]. / Avaliação do sistema de pontuação para o diagnóstico da tuberculose na infância preconizado pelo Ministério da Saúde, Brasil.

Tuberculosis is currently one of the main causes of death in the world. One of the difficulties for tuberculosis diagnosis in childhood is the bacteriological identification of Mycobacterium tuberculosis. This nested case-control study aimed to compare the diagnostic values of a scoring system proposed by the Brazilian Ministry of Heath for diagnosis of childhood tuberculosis using gastric washing samples taken in the outpatient and hospital settings. A total of 108 children underwent gastric washing (53 with and 55 without tuberculosis). The scoring system proposed by the Brazilian Ministry of Heath for diagnosis of tuberculosis in children with negative sputum smears showed good sensitivity in both groups, and the best cutoff point was "1" (possible tuberculosis), with 92% sensitivity, thus feasible for use as an ancillary diagnostic test in children submitted to gastric washing. Our recommendation is that the Ministry of Health scoring system be used by health services to assist the physician in deciding on whether to continue the investigation of childhood tuberculosis, and not only in children who have already undergone the procedure and who have shown negative results.

Sputum sample collected over a period of 5 h: A reliable procedure for early bactericidal activity studies.

Our study was designed to test the hypothesis that an early morning sputum may be sufficient for calculation of early bactericidal activity (EBA). Patients underwent sputum collection randomly (spot, 5 h and 12 h) in consecutive days. The median CFU count in the spot samples group was 5.67 log10 CFU/mL compared to 6.17 log10 CFU/mL in 5 h and 6.23 log10 CFU/mL in 12 h samples. Inter-patient comparison showed low coefficient of variation for both 12 h (11%) and 5 h samples (10%). Intrapatient samples analysis demonstrated that the median bacillary load variation (0.037 log10 CFU/mL and 0.022 log10 CFU/mL for 5 and 12 h samples respectively) was comparable to the other EBA studies and did not vary significantly from one day of collection to another. We concluded that 5 h pooled sputum when collected appropriately in the morning can be sufficient for calculation of EBA.

The impact of ocular tuberculosis on vision after two months of intensive therapy.

Tuberculosis is an infectious disease of global importance with major economic and social burden accounting for 25% of all avoidable deaths in developing countries. Extrapulmonary involvement may occur either in association with clinically apparent pulmonary tuberculosis or in isolation. This cross-sectional descriptive study aimed to evaluate the impact of ocular tuberculosis in visual acuity at baseline and after two months of intensive anti-tuberculous therapy. A sample of 133 pulmonary tuberculosis patients, seven disseminated tuberculosis, and three pleural tuberculosis patients was evaluated. All patients underwent routine ophthalmic evaluation, including assessment of visual acuity, biomicroscopy, applanation tonometry, indirect ophthalmoscopy, and fluorescent angiography as appropriate. None of the patients had impaired visual acuity due to tuberculosis. A rate of 4.2% (6/143) of ocular involvement was found. None of the patients with ocular involvement were HIV-infected. Of the six patients with ocular involvement, five met the diagnostic criteria for probable and one for possible ocular lesions. As for the type of ocular lesions, two patients had bilateral findings: one had sclerouveitis and the second had choroidal nodules. The other four patients presented with unilateral lesions: peripheral retinal artery occlusion in the right eye (one case), choroidal nodules in the left eye (one case), and choroidal nodules in the right eye (two cases). Patients progressed favorably after two month of intensive therapy, with no significant reduction in vision.

Cough-aerosol cultures of Mycobacterium tuberculosis in the prediction of outcomes after exposure. A household contact study in Brazil.

BACKGROUND: Mycobacterium tuberculosis cultures of cough-generated aerosols from patients with pulmonary tuberculosis (TB) are a quantitative method to measure infectiousness and to predict secondary outcomes in exposed contacts. However, their reproducibility has not been established. OBJECTIVE: To evaluate the predictive value of colony-forming units (CFU) of M. tuberculosis in cough aerosols on secondary infection and disease in household contacts in Brazil. METHODS: Adult sputum smear+ and culture+ pulmonary TB cases underwent a standard evaluation and were categorized according to aerosol CFU. We evaluated household contacts for infection at baseline and at 8 weeks with TST and IGRA, and secondary disease. RESULTS: We enrolled 48 index TB cases; 40% had negative aerosols, 27% low aerosols (<10 CFU) and 33% high aerosols (≥10 CFU). Of their 230 contacts, the proportion with a TST ≥10 mm at 8 weeks was 59%, 65% and 75%, respectively (p = 0.34). Contacts of high aerosol cases had greater IGRA readouts (median 4.6 IU/mL, IQR 0.02-10) when compared to those with low (0.8, 0.2-10) or no aerosol (0.1, 0-3.7; p = 0.08). IGRA readouts in TST converters of high aerosol cases (median 20 IU/mL, IQR 10-24) were larger than those from aerosol-negative (0.13, 0.04-3; p = o.o2). 8/9 (89%) culture+ secondary TB cases occurred in contacts of aerosol+ cases. CONCLUSION: Aerosol CFU predicts quantitatively IGRA readouts among household contacts of smear positive TB cases. Our results strengthen the argument of using cough aerosols to guide targeted preventive treatment strategies, a necessary component of current TB elimination projections.

Prevalence of mycobacteremia in patients with AIDS and persistant fever.

In the advanced stages of AIDS, characterized by severe immunodepression, tuberculosis (TB) may present with a clinical picture of septic shock, due to typical bacteremia. Hematogenic dissemination of mycobacteria is frequent in immunodepressed patients with TB or disseminated mycobacteriosis, leading to increased positivity in detection by automated blood culture. The objective of our study was to determine the prevalence of mycobacteremia in patients with AIDS and with prolonged fever seen at the Emilio Ribas Institute of Infectology. Patients with a history of daily fever (> or = 37.8 degrees C), lasting more than 30 days, and with CD4+ helper lymphocyte counts below 200 cells/mL, were selected from February 2001 to March 2002. A 5 mL peripheral blood sample was collected from each patient for mycobacterial blood culture by an automated method, using the BACTEC 9000 MB and MB/BACT techniques. Forty-five patients aged on average 35 years, most of them males, were included in the study. The mean T CD4+ lymphocyte count was 58 cells/mL. Among the samples submitted to blood culture, 30% gave M. tuberculosis growth, with 62% sensitivity. Among the patients with a negative blood culture, nine had received a diagnosis of TB by another method. Automated blood culture proved to be a technique of relevant diagnostic value for M. tuberculosis in patients with prolonged fever in advanced stages of AIDS. The method is simple, and it helps the physician to select the best therapeutic option.