A population-based study of drug resistance and transmission of tuberculosis in an urban community.

SETTING: A low-income neighborhood of Sao Paulo, Brazil. OBJECTIVE: To determine the incidence, risk factors and transmission patterns of multidrug-resistant tuberculosis (MDR-TB). DESIGN: Prospective longitudinal study of patients with pulmonary TB (PTB). METHODS: Sputum culture-confirmed patients with PTB were recruited between March 2000 and May 2002. Bivariate and multivariate logistic regression analyses were performed to identify factors associated with MDR-TB. Mycobacterium tuberculosis isolates were tested for drug susceptibility and typed by IS6110-RFLP analysis. RESULTS: Of 420 patients, respectively 71% and 27% were new and previously treated; 15.5% of the patients' M. tuberculosis isolates were resistant to at least one drug; of these, 11% and 27% were found among new and previously treated cases, respectively. Respectively 1% and 16.7% of the new and previously treated cases were MDR-TB. RFLP analysis showed that new transmission of MDR strains was uncommon. By multivariate logistic regression analysis, previous TB and hospitalization in the 24 months before TB diagnosis were identified as independent predictors of MDR-TB. CONCLUSIONS: The results showed an intermediate level of MDR-TB incidence in a neighborhood of Sao Paulo and identified predictors that can be targeted for intervention by national and local TB control programs.

Evaluation of a rapid differentiation test for the Mycobacterium tuberculosis complex by selective inhibition with rho-nitrobenzoic acid and thiophene-2-carboxylic acid hydrazide.

SETTING: Mycobacterial growth in media to which inhibitory substances are added has been used in species identification. Growth of the Mycobacterium tuberculosis complex (MTC) is inhibited by rho-nitrobenzoic acid (PNB), whereas non-tuberculous mycobacteria (NTM) are resistant. Thiophene-2-carboxylic acid hydrazide (TCH) is useful in the differentiation of MTC when performed together with other tests. OBJECTIVE: To develop a test using PNB or TCH added to culture medium, and to evaluate its usefulness in the screening of mycobacteria isolates. DESIGN: In 2001, PNB testing was performed in 109 M. tuberculosis strains identified by Instituto Adolfo Lutz (IAL) and 52 NTM strains from the institute's culture collection. The drugs were added to Löwenstein-Jensen (LJ) medium and to BBL-MGIT. RESULTS: Species differentiation of MTC with the MGIT/TCH method was similar to that observed using the conventional LJ/TCH method. The accuracy of the MGIT/PNB method to differentiate NTM and MTC strains was 99.4%. The BBL-MGIT system allowed presumptive identification in 3-11 days, compared to > or =12 days with LJ medium. CONCLUSION: A simple, low-cost test using growth inhibitors may be incorporated into a modern, safe and quick methodology enabling differentiation of MTC and NTM.

Mycobacterium tuberculosis bacteremia diagnosed in an HIV-negative patient in Brazil: a rare or an under-reported event?

A case of Mycobacterium tuberculosis bacteremia in an HIV negative immunodepressed patient was described using the BACTEC 460 TB system. This bacterium should be investigated in the blood of immunodepressed non-HIV infected patients with prolonged fever.

Mycobacterium tuberculosis bacteremia diagnosed in an HIV-negative patient in Brazil: a rare or an under-reported event?

A case of Mycobacterium tuberculosis bacteremia in an HIV negative immunodepressed patient was described using the BACTEC 460 TB system. This bacterium should be investigated in the blood of immunodepressed non-HIV infected patients with prolonged fever.

Mycobacteraemia among HIV-1-infected patients in São Paulo, Brazil: 1995 to 1998.

From July 1995 to August 1998, mycobacterial blood cultures were obtained from 1032 HIV-infected patients seen at the Centro de Referência e Treinamento de AIDS (CRTA), Hospital São Paulo (HSP), and Centro de Referência de AIDS de Santos (CRAS). Overall, 179 episodes of mycobacteraemia were detected: 111 (62.0%) at CRTA, 50 (27.9%) at HSP, and 18 (10.1%) at CRAS. The frequency of positive cultures declined sharply from 22.6% in 1995 to 6.9% in 1998, consistent with the decrease in opportunistic infections following the publicly funded distribution of highly active antiretroviral therapy. In 1995, mycobacteraemia was more frequently due to Mycobacterium avium complex (59.2%) than Mycobacterium tuberculosis (28.6%), whereas in 1998 the relative frequencies were reversed (28.6 vs. 64.3% respectively), probably justified by the increased virulence of M. tuberculosis and the greater risk of invasive infection in less-immunocompromised patients, including patients unaware they are infected with HIV.

Rapid detection of multidrug-resistant Mycobacterium tuberculosis using the mycobacteria growth indicator tube (MGIT) system.

The emergence of multidrug-resistant strains of Mycobacterium tuberculosis has increased the need for rapid drug susceptibility tests, which are needed for adequate patient treatment. The objective of the present study was to evaluate the mycobacteria growth indicator tube (MGIT) system to detect multidrug-resistant M. tuberculosis strains. The MGIT system was compared with two standard methods (proportion and resistance ratio methods). One hundred clinical M. tuberculosis isolates [25 susceptible to isoniazid (INH) and rifampicin (RIF), 20 resistant to INH, 30 resistant to INH-RIF, and 25 resistant to INH-RIF and other drugs] obtained in the State of S o Paulo were tested for INH and RIF susceptibility. Full agreement among the tests was found for all sensitive and all INH-resistant strains. For RIF-resistant strains results among the tests agreed for 53 (96.4%) of 55 isolates. Results were obtained within 6 days (range, 5 to 8 days), 28 days and 12 days when using MGIT, the proportion method and the resistance ratio methods, respectively. The MGIT system presented an overall agreement of 96% when compared with two standard methods. These data show that the MGIT system is rapid, sensitive and efficient for the early detection of multidrug-resistant M. tuberculosis.

Rapid detection of multidrug-resistant Mycobacterium tuberculosis using the mycobacteria growth indicator tube (MGIT) system

The emergence of multidrug-resistant strains of Mycobacterium tuberculosis has increased the need for rapid drug susceptibility tests, which are needed for adequate patient treatment. The objective of the present study was to evaluate the mycobacteria growth indicator tube (MGIT) system to detect multidrug-resistant M. tuberculosis strains. The MGIT system was compared with two standard methods (proportion and resistance ratio methods). One hundred clinical M. tuberculosis isolates [25 susceptible to isoniazid (INH) and rifampicin (RIF), 20 resistant to INH, 30 resistant to INH-RIF, and 25 resistant to INH-RIF and other drugs] obtained in the State of Säo Paulo were tested for INH and RIF susceptibility. Full agreement among the tests was found for all sensitive and all INH-resistant strains. For RIF-resistant strains results among the tests agreed for 53 (96.4 percent) of 55 isolates. Results were obtained within 6 days (range, 5 to 8 days), 28 days and 12 days when using MGIT, the proportion method and the resistance ratio methods, respectively. The MGIT system presented an overall agreement of 96 percent when compared with two standard methods. These data show that the MGIT system is rapid, sensitive and efficient for the early detection of multidrug-resistant M. tuberculosis

Infecçäo causada por Mycobacterium tuberculosis com resistência primária a múltiplas drogas: relato de caso em paciente com AIDS / Infection caused by Mycobacterium tuberculosis with primary resistance to multiple drugs: a case report of a patient with AIDS

Mycobacterium tuberculosis, primariamente resistente a múltiplas drogas, é problema de crescente importância nos Estados Unidos. No Brasil, näo existem relatos, pelo menos em literatura formal, de infecçäo por este patógeno. Relato de caso. Os autores relatam caso de paciente do sexo masculino que teve diagnóstico de tuberculose ganglionar cervical por meio de baciloscopia. Adicionalmente, anti-HIV feito por método ELISA resultou positivo. O paciente iniciou esquema terapêutico com isoniazida, rifampicina e pirazinamida. Segundo o paciente e seus familiares, os medicamentos foram administrados corretamente, mas näo foi observada melhora clínica. Após 75 dias de tratamento, o paciente foi internado no Hospital do Servidor Público Estadual de Säo Paulo com piora clínica caracterizada por aumento de gânglio submandibular, insuficiência respiratória e dor abdominal, vindo a falecer seis dias após a admissäo. Cultura do aspirado ganglionar, colhida no dia da internaçäo, mostrou crescimento de M. tuberculosis sensível ao etambutol e resistente à isoniazida, rifampicina, pirazinamida, etionamida e estreptomicina. Discussäo. O isolamento de M. tuberculosis multirresistente, mesmo que em paciente com forma extra-pulmonar da doença, traz à tona discussäo da necessidade da prevalência do patógeno em nosso meio mediante realizaçäo de cultura e antibiograma, e ressalta problemas inerentes à MTB-MDR, como a alta letalidade em pacientes com infecçäo clinicamente manifesta e a transmissäo intra-hospitalar, já demonstrada em outros países. É discutida a necessidade de cumprimento rigoroso das medidas de isolamento