Molecular diversity of Mycobacterium tuberculosis strains in a slum area of Rio de Janeiro, Brazil / Diversidade molecular de cepas de Mycobacterium tuberculosis em uma região de favela da cidade do Rio de Janeiro

This retrospective molecular study involving restriction fragment length polymorphism, using insertion sequence 6110 as a marker, was conducted in order to provide an initial insight into the genetic diversity of Mycobacterium tuberculosis strains isolated in the slums of the Complexo de Manguinhos, located in the city of Rio de Janeiro, Brazil. Of the 67 strains evaluated, 23 (34.3 percent) were found to belong to clusters (total clusters, 10). Household and social chains of transmission were associated with clustering, in 20 percent and 60 percent, respectively. Living in the Conjunto Habitacional Programado 2 slum was associated with clustering. Although not significant, it is relevant that 26 percent of the clustered strains presented primary resistance. These findings, although possibly underestimating the prevalence due to the failure to analyze all strains, could help improve the local tuberculosis control program.

Este estudo retrospectivo envolvendo polimorfismo de fragmento de restrição e utilizando como marcador a seqüência de inserção 6110, foi realizado para fornecer informações iniciais quanto à diversidade genética das cepas de Mycobacterium tuberculosis isoladas em favelas do Complexo de Manguinhos, na cidade do Rio de Janeiro. Das 67 cepas isoladas, 23 (34,3 por cento) foram agrupadas em clusters (total de clusters, 10). A transmissão entre comunicantes domiciliares e extra-domicialiares estave associada a 20 por cento e 60 por cento dos clusters, respectivamente. Ser morador do Conjunto Habitacional Programado 2 foi associado à presença de clusters. Embora não significativo, é relevante o fato de que 26 por cento das cepas em cluster apresentaram resistência primária. Estes achados, embora possivelmente subestimados devido à impossibilidade de analisar todas as cepas, fornecem subsídios para a melhoria do programa local de controle da tuberculose.

Resistência a drogas em cepas de mycobacterium tuberculosis isoladas de amostras de escarro de pacientes ambulatoriais sintomáticos: Complexo de Manguinhos, Rio de Janeiro, Brasil / Drug resistance in mycobacterium tuberculosis strains isolated from sputum samples from symptomatic outpatients: Complexo de Manguinhos, Rio de Janeiro, Brazil

Para descrever a resistência a drogas em cepas de Mycobacterium tuberculosis isoladas de amostras de escarro de 263 pacientes suspeitos de tuberculose moradores do Complexo de Manguinhos, Rio de Janeiro, Brasil, as culturas positivas entre outubro de 2000 e dezembro de 2002 foram submetidas a teste de sensibilidade para isoniazida, rifampicina, estreptomicina, etionamida e etambutol. Resistência a qualquer das drogas foi encontrada em 21,4 por cento (16/75) dos pacientes diagnosticados com tuberculose. Destes, 50 por cento (8/16) eram casos novos e 50 por cento (8/16) eram casos com tratamento anterior. A tuberculose multirresistente foi encontrada em 10,6 por cento (8/75) do total de pacientes, estando associada a tratamento anterior em 8 por cento (6/75) deles. Nossos resultados podem ter sido subestimados, pois M. tuberculosis não pôde ser isolado em todas as amostras positivas para bacilos álcool-ácido resistentes. Contudo, eles pelo menos revelam parte do problema.

This study aimed to assess drug resistance in Mycobacterium tuberculosis strains isolated from sputum samples. To that end, sputum samples were collected from 263 patients suspected of having tuberculosis. All subjects lived in the Complexo de Manguinhos, which is located in the city of Rio de Janeiro, Brazil. Cultures testing positive between October of 2000 and December of 2002 were tested to determine strain susceptibility to isoniazid, rifampicin, streptomycin, ETHionamide, and ETHambutol. Of the 75 patients diagnosed with tuberculosis, resistance to at least one of the drugs was found in 16 (21.4 percent). Of those 16 patients, 8 (50 percent) were new cases, and 8 (50 percent) had previously been treated. Multidrug-resistant tuberculosis was identified in 8 (10.6 percent) of the 75 patients, being associated with previous treatment in 6 (8 percent). The incidence of multidrug-resistant tuberculosis might have been underestimated, since M. tuberculosis was not isolated from all of the samples testing positive for acid-fast bacilli. However, at least, our findings shed some light on the problem.

Um estudo retrospectivo dos aspectos epidemiológicos da tuberculose na comunidade do Complexo de Manguinhos localizado em área urbana do Rio de Janeiro, Brasil, 2000-2002 / A retrospective study of the epidemiological aspects of tuberculosis in the Complexo de Manguinhos, an urban slum area in Rio de Janeiro, Brazil, 2000-2002

To describe some aspects of tuberculosis in a low-income community (the Complexo de Manguinhos, in Rio de Janeiro, Brazil), a retrospective study was carried out. Of the 290 cases reported in the 2000-2002 period, 75.8 percent were new cases. The annual incidence rates were 157/100,000 (2000), 205/100,000 (2001), and 145/100,000 (2002). Although there was a tendency toward a decrease in the number of cases over the period studied, the difference was not significant, suggesting that tuberculosis continues to be endemic in the area. Therefore, despite the existence of local public health care services, more efficient strategies should be implemented in order to increase the effectiveness of tuberculosis control programs in the area.

Para descrever alguns aspectos da tuberculose em favelas, foi realizado um estudo retrospectivo no Complexo de Manguinhos, Rio de Janeiro (RJ) Brasil. Em um total de 290 casos notificados entre 2000 e 2002, 75,8 por cento eram casos novos. A taxa de incidência foi de 157, 205 e 145/100.000, respectivamente. Embora tenha sido observada tendência de diminuição dos números de casos no período de estudo, esta não foi significante, sugerindo manutenção da endemia. Portanto, embora exista um serviço de saúde no local, estratégias mais eficientes devem ser implantadas para auxiliar o Programa de Controle da tuberculose.

Non-tuberculous mycobacteria I: one year clinical isolates identification in Tertiary Hospital Aids Reference Center, Rio de Janeiro, Brazil, in pre highly active antiretroviral therapy era

The aim of this study was to determine the prevalence of non-tuberculous mycobacteria (NTM) isolates at University Hospital, Reference Center for Aids in Rio de Janeiro, Brazil, during one year. We used standard biochemical tests for species identification and IS1245 PCR amplification was applied as a Mycobacterium avium specific identification marker. Four hundred and four specimens from 233 patients yielded acid-fast bacilli growth. M. tuberculosis was identified in 85 percent of the patients and NTM in 15 percent. NTM disseminated infection was a common event correlated with human immunodeficiency virus (HIV) infected patients and only in HIV negative patients the source of NTM was non sterile site. M. avium complex (MAC) was biochemically identified in 57.8 percent (49/83) of NTM isolates, most of them from sterile sites (75.5 percent), and in 94 percent (46/49) the IS 1245 marker specific for M. avium was present. Twenty NTM strains showed a MAC biochemical pattern with the exception of a urease-positive (99 percent of MAC are urease-negative), however IS1245 was detected in 96 percent of the strains leading to their identification as M. avium. In this group differences in NTM source was not significant. The second most frequently isolated NTM was identified as M. scrofulaceum (7.2 percent), followed by M. terrae (3.6 percent), M. gordonae (2.4 percent), M. chelonae (1.2 percent), M. fortuitum (1.2 percent) and one strain which could not be identified. All were IS1245 negative except for one strain identified as M. scrofulaceum. It is interesting to note that non-sterile sites were the major source of these isolates (92.8 percent). Our finding indicated that M. avium is still the major atypical species among in the MAC isolates recovered from Brazilian Aids patients without highty active antiretroviral therapy schema. Some discrepancies were seen between the identification methods and further investigations must be done to better characterize NTM isolates using other phenotypic and genotypic methods