A case-control study of protection against tuberculosis by BCG revaccination in Recife, Brazil.

SETTING: Metropolitan region of Recife, Brazil. OBJECTIVE: To estimate the additional protection against tuberculosis (TB) provided by a second dose of bacille Calmette-Guérin (BCG) vaccine. DESIGN: Case-control study. Cases were cases of TB newly diagnosed by the TB control programme, independent of clinical form. Three matched neighbourhood controls were selected using a systematic routine, starting from the case's address. The matching was within the age groups 7-9, 10-14 and 15-19 years. RESULTS: Analysis was conducted among 169 cases and 477 controls. For the efficacy of BCG revaccination against TB overall, matched (crude) vaccine effectiveness (VE) was -3 (95% CI -50-29) and matched (adjusted) VE was 8 (95% CI -77-52). CONCLUSIONS: This study suggests that a second dose of BCG does not offer additional protection. Revaccination should not be offered. As large numbers of subjects are already vaccinated and vaccine appears to offer some protection in older subjects, further studies with larger sample sizes could investigate the potential efficacy of revaccination with BCG in the age group > or = 15 years

O retratamento da tuberculose no município do Recife, 1997: uma abordagem epidemiológica Repeated treatment of tuberculosis in the city of Recife, 1997: an epidemiological approach

Objetivo: Este estudo descreve as características e analisa o acompanhamento de casos de retratamento ocorridos em residentes no município do Recife, no ano de 1997, com o objetivo de avaliar a importância deste grupo de doentes para a vigilância da tuberculose nos sistemas locais de saúde. Casuística e métodos: Foi realizado um estudo transversal com uma amostra de 240 casos de retratamento que representaram 16,2% dos casos de tuberculose notificados à Secretaria Estadual de Saúde do Estado de Pernambuco, em 1997. Resultados: O abandono do tratamento anterior foi o principal motivo para o retratamento (55,8%), seguido por casos de recidiva da doença (39,2%). Os doentes eram predominantemente do sexo masculino, com idade entre 30 e 49 anos, com baixa ou nenhuma escolaridade, e apresentavam um predomínio da forma pulmonar. Chama a atenção que 42,7% dos casos de retratamento tinham história de dois ou mais tratamentos anteriores. Em relação ao desfecho do retratamento, 52,5% dos casos apresentaram resultado desfavorável. Entre estes, 44,2% dos indivíduos abandonaram o esquema terapêutico e 39,6% deles fizeram-no até o primeiro mês. Os casos que voltaram a tratar-se após recidiva apresentaram maior percentual de desfecho favorável de retratamento (64%) quando comparados com os casos que voltaram a tratar-se após falência ou abandono do tratamento anterior e esta diferença foi estatisticamente significante (chi² = 19,55; p < 0,01). Entre os casos da forma pulmonar de tuberculose, 27,1% reiniciaram a quimioterapia sem realizar a pesquisa do bacilo de Koch no escarro e apenas 5% realizaram cultivo com teste de sensibilidade. Encontrou-se ainda que 30,2% dos casos voltaram a tratar-se apenas com as drogas do esquema I. Conclusões: Os resultados encontrados apontam para a necessidade de implementar as atividades de assistência e seguimento dos casos de retratamento de tuberculose, de forma rotineira, no âmbito dos serviços de saúde. O tratamento com drogas adequadas e o acompanhamento dos doentes até a cura são métodos simples e baratos para prevenir o aparecimento de cepas de bacilos resistentes às drogas. Devem, portanto, ser entendidos como estratégias de fortalecimento do sistema de vigilância epidemiológica à tuberculose no nível local.<br>Objectives: This study describes the epidemiological profile of cases of repeated treatment of tuberculosis occurring among residents of the city of Recife in the year of 1997. Material and methods: A cross-sectional study was performed and 240 cases of repeated treatment were studied, representing 16.2% of all cases of tuberculosis. Results: Interruption of previous treatment was the principal reason for repeated treatments (55.8%), followed by cases of recurrence of the disease (39.2%). Patients undergoing repeated treatment for tuberculosis are characterized as predominantly male, ages between 30 and 49, with little or no school education, with a significant predominance of pulmonary tuberculosis. It is striking that 42.7% of the cases of repeated treatment had a history of two or more previous courses of treatment. With regard to the outcome of the repeated treatment, 52.5% of the cases showed unfavorable results. Among these, 44.2% of the patients gave up the course of treatment and 39.6% followed it for the first month. The cases that returned for treatment following recurrence showed a higher percentage of successful outcomes (56.7%), in comparison to those that returned after interrupting previous treatment (40.2%), this difference being statistically significant (chi² = 19,55; p < 0,01). It was found that, among the cases of pulmonary tuberculosis, 27.1% resumed chemotherapy without undergoing the Koch bacillus catarrh test and only 27.1% carried out BK culture with sensitivity test. Conclusions: The results show the need to enhance tuberculosis treatment and follow-up procedures within the sphere of the health care service. An adequate treatment is the cheapest method to avoid drug resistance and should be understood as a strategy to improve the tuberculosis surveillance system