A study of multidrug-resistant tuberculosis in risk groups in the city of Santos, São Paulo, Brazil

Monitoring the extent of and trends in multidrug-resistant tuberculosis (MDR-TB) is a priority of the Brazilian National Tuberculosis Control Programme. The current study aimed to estimate the incidence of MDR-TB, describe the profile of TB drug resistance in risk groups and examine whether screening for MDR-TB adhered to the recommended guidelines. A descriptive study that examined diagnosed cases of pulmonary TB was conducted in the city of Santos, Brazil, between 2000-2004. Of the 2,176 pulmonary TB cases studied, 671 (30.8%) met the criteria for drug sensitivity testing and, of these cases, 31.7% (213/671) were tested. Among the tested cases, 9.4% were resistant to one anti-TB drug and 15% were MDR. MDR was observed in 11.6% of 86 new TB cases and 17.3% of 127 previously treated cases. The average annual incidence of MDR-TB was 1.9 per 100,000 inhabitants-years. The extent of known MDR-TB in the city of Santos is high, though likely to be underestimated. Our study therefore indicates an inadequate adherence to the guidelines for MDR-TB screening and suggests the necessity of alternative strategies of MDR-TB surveillance

Estudo comparativo entre um sistema de sonda genética e métodos clássicos na identificação das micobactérias

OBJETIVO: O aparecimento da co-infecção tuberculose/HIV e o aumento de casos de doenças provocadas por micobactérias não-tuberculosas (MNT) exigem repostas laboratoriais rápidas tanto no isolamento como na identificação das micobactérias. O objetivo deste trabalho foi avaliar a identificação das micobactérias através de sonda genética em comparação com os métodos bioquímicos clássicos. MÉTODOS: Entre 2002 e 2004, foram analisadas 178 culturas de micobactérias, confirmadas como bacilos álcool-ácido resistentes e obtidas de isolados clínicos de pacientes sintomáticos respiratórios ou com suspeita clínica de tuberculose pulmonar e/ou micobacterioses, atendidos nas Unidades de Saúde da Baixada Santista. RESULTADOS: A sonda genética identificou 137 amostras (77%) como complexo Mycobacterium tuberculosis e 41 (23%) como MNT. A discordância observada de 3% entre os métodos ocorreu apenas no ano de implantação (2002). Ao comparar os métodos, a sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo da sonda genética foram 98%, 93%, 98% e 93%, respectivamente. CONCLUSÕES: Apesar do custo elevado, a identificação de micobactérias pela técnica molecular é mais rápida: máximo de 3 h vs. 28-30 dias para os métodos clássicos. A utilização de sondas genéticas é uma técnica molecular validada, simples e disponível no mercado, com elevada especificidade, sensibilidade e rapidez, o que justifica sua implantação e uso rotineiro em laboratórios de referência, facilitando o diagnóstico e permitindo uma intervenção clínica ágil

Epidemiological and laboratorial profile of patients with isolation of nontuberculous mycobacteria

Background: An increase in NTM diseases in the international scenario has been observed in recent years. Aims: To analyze the epidemiological and laboratory profiles of patients with isolation of nontuberculous mycobacteria (NTM) over one decade. A retrospective analysis of records of a mycobacterial reference laboratory found 135 cases with isolation of NTM. Methods: Clinical and epidemiological data were collected from the records of government health clinics and from the State notification system (TBWEB). The cases were geocoded by location based on the street address in the Mercator Transverse Universal projection, Datum SAD/69 and MapInfo software. Results: Most patients were male (66.7%), older than 50 years (40%) and had only completed elementary schooling (38.5%). Associated health problems were found in 71.8% of the subjects, with 43.7% being HIV positive and 25.9% having had tuberculosis in the past. Hospitals were the most able institutions to diagnose cases (45.2%). Sputum was the most common material tested (63.0%) with the bacilloscopy being positive in 33.3% of cases. The most common mycobacteria species in the region were Mycobacterium avium and M. abscessus/M. massiliense/M. bolletii. When the regional reference municipality was analyzed, M. avium and M. fortuitum were the most common species isolated in the urban area. Conclusions: In the study region, mycobacteriosis most affected adult males with low schooling. Most patients presented comorbidities in particular co-infection with the HIV virus. M. avium is the most prevalent species in the region with the M. abscessus/M. massiliense/M. bolletii species being the main cause of nosocomial infections