 |
Design of the Brazilian BCG-REVAC trial
against tuberculosis: a large, simple randomized community trial to
evaluate the impact on tuberculosis of BCG revaccination at school age
Mauricio L. Barreto M.D., M.P.H., Ph.D.
* a , Laura C.
Rodrigues M.Sc., Ph.D. b , Sergio S.
Cunha M.D., M.P.H. a , Susan Pereira
M.D., M.P.H. a , Miguel A. Hijjar M.D.
c , Maria Yury Ichihara M.D., M.P.H.
a , Silvana C. de Brito B.Sc.
a and Ines Dourado M.D., M.P.H., Ph.D.
a
Received: 9/11/2001. Accepted: 4/8/2002.
Abstract
This paper describes the design and baseline results of a large and
simple randomized controlled trial of the protection against
tuberculosis of a dose of Bacillus Calmette Guerin (BCG) vaccination
given to school children in a population with a high coverage of
neonatal BCG (The Brazilian BCG-REVAC trial). The study started in 1996
and is a pair-matched and stratified-cluster randomized controlled trial
with no placebo. The study population consists of children aged 7–14
years enrolled in 763 state schools from the cities of Salvador and
Manaus, Brazil. Schools were the unit of randomization. Identifying
information was collected for 354,708 school children. The final study
population, after exclusions on the basis of age, BCG scar readings and
absence from school on the day of the study visit, consists of 242,401
children, of whom 125,403 are in intervention schools. Follow-up relies
on ascertainment of cases diagnosed at the health services and notified
to the tuberculosis control program surveillance system. Blindness is
guaranteed during linkage and validation of cases. Analysis is planned
for the next 12 months, where efficacy will be estimated by calculating
incidence of tuberculosis in the vaccine and control groups, taking into
consideration the cluster design. The intervention studied, a second BCG
vaccination, is widely used, although the World Health Organization does
not recommend it on the basis of absence of evidence of protection or
lack of protection. The results of the trial will make it possible for
BCG revaccination practice to be informed by evidence. This is an
example of a large simple and relatively inexpensive effectiveness
trial, resulting from good collaboration between academia and health and
education services enabling developing countries to define policies that
are relevant for their reality.
Affiliations:
a Instituto de Saúde
Coletiva, Universidade Federal da Bahia, Salvador, Bahia, Brazil.
b London School of
Hygiene and Tropical Medicine, London, England, UK.
c Centro de Refereåncia
Helio Fraga, FUNASA/Ministry of Health, Rio de Janeiro, Brazil.
Copyright
© 2002 Elsevier Science Inc. All rights reserved.
|
Search
for articles: