The presence of a booster phenomenon among contacts of active pulmonary tuberculosis cases: a retrospective cohort.

BACKGROUND: Assuming a higher risk of latent tuberculosis (TB) infection in the population of Rio de Janeiro, Brazil, in October of 1998 the TB Control Program of Clementino Fraga Filho Hospital (CFFH) routinely started to recommend a two-step tuberculin skin test (TST) in contacts of pulmonary TB cases in order to distinguish a boosting reaction due to a recall of delayed hypersensitivity previously established by infection with Mycobacterium tuberculosis (M.tb) or BCG vaccination from a tuberculin conversion. The aim of this study was to assess the prevalence of boosted tuberculin skin tests among contacts of individuals with active pulmonary tuberculosis (TB). METHODS: Retrospective cohort of TB contacts > or = 12 years old who were evaluated between October 1st, 1998 and October 31st 2001. Contacts with an initial TST < or = 4 mm were considered negative and had a second TST applied after 7-14 days. Boosting reaction was defined as a second TST > or = 10 mm with an increase in induration > or = 6 mm related to the first TST. All contacts with either a positive initial or repeat TST had a chest x-ray to rule out active TB disease, and initially positive contacts were offered isoniazid preventive therapy. Contacts that boosted did not receive treatment for latent TB infection and were followed for 24 months to monitor the development of TB. Statistical analysis of dichotomous variables was performed using Chi-square test. Differences were considered significant at a p < 0.05. RESULTS: Fifty four percent (572/1060) of contacts had an initial negative TST and 79% of them (455/572) had a second TST. Boosting was identified in 6% (28/455). The mean age of contacts with a boosting reaction was 42.3 +/- 21.1 and with no boosting was 28.7 +/- 21.7 (p = 0.01). Fifty percent (14/28) of individuals whose test boosted met criteria for TST conversion on the second TST (increase in induration > or = 10 mm). None of the 28 contacts whose reaction boosted developed TB disease within two years following the TST. CONCLUSION: The low number of contacts with boosting and the difficulty in distinguishing boosting from TST conversion in the second TST suggests that the strategy of two-step TST testing among contacts of active TB cases may not be useful. However, this conclusion must be taken with caution because of the small number of subjects followed.

Efeitos adversos hepáticos durante o tratamento para tuberculose em hospital geral referência para Aids, Rj, Brasil / Hepatic adverse efects anti-tuberculosis tratment in a geral hospital, Rio de Janeiro, Brasil

Introdução: a frequência de efeitos adversos hepáticos e os fatores associados com a sua ocorrência em um hospital universitário referência para Aids e tuberculose não é completamente conhecida. Métodos: foi realizado um estudo tipo caso-controle com o objetivo de medir prevalência de efeitos hepáticos adversos (EAH) em pacientes sob tratamento medicamentoso anti-tuberculose (TB) e de fatores associados à sua ocorrência. Resultados: foram analisados 588 prontuários médicos de pacientes que fizeram uso de esquema anti-TB com isoniazida, rifampicina e pirazinamida, acrescido ou não de etambutol, atendidos no período de Janeiro de 1994 a dezembro de 1995. EAH foi observado em 40 (6,8%) casos. Foram pareados 200 casos para o grupo controle. Na análise univariada dos grupos caso e controle não houve diferença estatisticamente significativa entre a ocorrência de EAH e os seguintes parâmetros: a idade, gênero esquema inicial de tratamento anti-TB, a história prévia de hepatopatia e/ou presença de alcoolismo. Entretanto, a ocorrência de EAH esteve significamente associada a hospitalização no momento do diagnóstico da TB, a presença de síndrome de imunodeficiência adquirida (SIDA/AIDS), a forma disseminada da TB, a apresentação radiográfica atípica da TB pulmonar, a sorologia positiva para hepatite a vírus B e/ou C, e a evolução clínica desfavorável ou tratamento. Na análise multivariada, somente a hospitalização e o diagnóstico de SIDA permaneceram associados significantemente a EAH. Conclusões: em um hospital Universitário, referência para AIDS e TB, a presença de Aids, de imagem radiológica de TB pulmonar atípica e a TB disseminada estão associados a uma maior taxa de EAH.

Introduction: the frequency of hepatic adverse effects and factors associated with its occurrence in an Universitary Hospital, reference for AIDS and tuberculosis (TB) is not completely known. Methods: a case-control study was conducted to assess the prevalence of hepatic adverse effects of patients using anti-TB treatment and the factors associated with its occurrence. Results: 588 medical charts of TB patients receiving anti-TB treatment with isoniazid, ripampin, pirazinamide, with or without ethambutol attendent betwee January, 1994 and December, 1995 were analyzed. HAE was observed in 40 (6.8%) patients. Two-hundred patients were included as control group. Using univariate analysis to evaluate case and control groups no statistically difference was found between HAE and the following variables: age, gender, anti-TB treatment, liver disease in the past and/or alcohol abuse. However, HAE was significantly associated with hospitalization at the time that TB diagnosis was made, immunosupression, disseminated TB, radiographic atypical presentation of pulmonary TB, seropositivy for B and C hepatitis and clinical unfavorable evolution. In multivariate analysis only hospitalization and Aids were associated to HAE. Conclusion: in a University Hospital, reference for TB and AIDS, the presence of Aids, radiographic atypical presentation of pulmonary TB and disseminated form of TB were associated with higher prevalence of HAE.