Authors: Teixeira, E.G.1; Kritski, A.2; Ruffino-Netto, A.3; Steffen, R.4; Lapa e Silva, J.R.2; Belo, M.5; Luiz, R.R.2; Menzies, D.6; Trajman, A.7

Source: The International Journal of Tuberculosis and Lung Disease, Volume 12, Number 12, December 2008 , pp. 1407-1413(7)

Publisher: International Union Against Tuberculosis and Lung Disease

Abstract:

SETTING: Five medical schools in three cities in Rio de Janeiro State, Brazil, with different tuberculosis (TB) incidence rates.

OBJECTIVE: To evaluate the prevalence of the booster phenomenon and its associated factors in a young universally BCG-vaccinated TB-exposed population.

DESIGN: A two-step tuberculin skin test (TST) was performed among undergraduate medical students. Boosting was defined as an induration ≥10 mm in the second TST (TST2), with an increase of at least 6 mm over the first TST (TST1). The association of boosting with independent variables was evaluated using multivariate analysis.

RESULTS: Of the 764 participants (mean age 21.9 ± 2.7 years), 672 (87.9%) had a BCG scar. The overall booster phenomenon prevalence was 8.4% (95%CI 6.5-10.6). Boosting was associated with TST1 reactions of 1-9 mm (aOR 2.5, 95%CI 1.04-5.9) and with BCG vaccination, mostly after infancy, i.e., after age two years (aOR 9.1, 95%CI 1.2-70.7).

CONCLUSION: The prevalence of the booster phenomenon was high. A two-step TST in young BCG-vaccinated populations, especially in those with TST1 reactions of 1-9 mm, can avoid misdiagnosis as a false conversion and potentially reduce unnecessary treatment for latent TB infection. 
Keywords: BCG; booster; medical students; tuberculin test; tuberculosis

Document Type: Regular paper

Affiliations: 1: Gama Filho University, Rio de Janeiro, Rio de Janeiro, Brazil; Souza Marques Foundation, Rio de Janeiro, Rio de Janeiro, Brazil; Rio de Janeiro Federal University, Rio de Janeiro, Rio de Janeiro, Brazil 2: Rio de Janeiro Federal University, Rio de Janeiro, Rio de Janeiro, Brazil 3: Ribeirão Preto School of Medicine, São Paulo University, Ribeirao Preto, São Paulo, Brazil 4: Souza Marques Foundation, Rio de Janeiro, Rio de Janeiro, Brazil 5: Gama Filho University, Rio de Janeiro, Rio de Janeiro, Brazil; Souza Marques Foundation, Rio de Janeiro, Rio de Janeiro, Brazil 6: Montreal Chest Institute, McGill University, Montreal, Quebec, Canada 7: Gama Filho University, Rio de Janeiro, Rio de Janeiro, Brazil

Saiba mais em: http://www.ingentaconnect.com/content/iuatld/ijtld/2008/00000012/00000012/art00013

Sobre a REDE-TB

A Rede Brasileira de Pesquisa em Tuberculose (REDE-TB) é uma Organização Não Governamental (ONG) de direito privado sem fins lucrativos, preocupada em auxiliar no desenvolvimento não só de novos medicamentos, novas vacinas, novos testes diagnósticos e novas estratégias de controle de TB, mas também na validação dessas inovações tecnológicas, antes de sua comercialização no país e/ou de sua implementação nos Programa de Controle de TB no País.


bt2

Contato

E-mail: redetb.rp@gmail.com

Tel: +55 (21)3938 - 2426
Tel/ Fax: +55 (21)3938 - 2431.

Endereço: Avenida Carlos Chagas Filho, 791, Cidade Universitária - Ilha do Fundão, Rio de Janeiro, RJ - Brasil. CEP: 21941-904

Assine a newsletter da REDE-TB

Curta REDE-TB no Facebook