Tuberculin reactivity in a population of schoolchildren with high BCG vaccination coverage
Rev. panam. salud pública
;
13(5): 285-293, May 2003. tab, graf
Article
Dans Anglais
| LILACS
| ID: lil-346136
RESUMO
OBJECTIVE:
To investigate the influence of BCG vaccination or revaccination on tuberculin skin test reactivity, in order to guide the correct interpretation of this test in a setting of high neonatal BCG vaccination coverage and an increasing BCG revaccination coverage at school age.METHODS:
We conducted tuberculin skin testing and BCG scar reading in 1148 children aged 7-14 years old in the city of Salvador, Bahia, Brazil. We measured the positive effect of the presence of one or two BCG scars on the proportion of tuberculin skin test results above different cut-off levels (induration sizes of > 5 mm, > 10 mm, and > 15 mm) and also using several ranges of induration size (0, 1-4, 5-9, 10-14, and > 15 mm). We also measured the effects that age, gender, and the school where the child was enrolled had on these proportions.RESULTS:
The proportion of tuberculin results > 10 mm was 14.2 percent (95 percent confidence interval (CI) = 8.0 percent-20.3 percent) for children with no BCG scar, 21.3 percent (95 percent CI = 18.5 percent-24.1 percent) for children with one BCG scar, and 45.0 percent (95 percent CI = 32.0 percent-58.0 percent) for children with two BCG scars. There was evidence for an increasing positive effect of the presence of one and two BCG scars on the proportion of results > 5 mm and > 10 mm. Similarly, there was evidence for an increasing positive effect of the presence of one and two scars on the proportion of tuberculin skin test results in the ranges of 5-9 mm and of 10-14 mm. The BCG scar effect on the proportion of results > 5 mm and > 10 mm did not vary with age. There was no evidence for BCG effect on the results > 15 mm.CONCLUSIONS:
In Brazilian schoolchildren, BCG-induced tuberculin reactivity is indistinguishable, for results under 15 mm, from reactivity induced by Mycobacterium tuberculosis infection. BCG revaccination at school age increases the degree of BCG-induced tuberculin reactivity found among schoolchildren. This information should be taken into account in tuberculin skin test surveys intended to estimate M. tuberculosis prevalence or to assess transmission patterns as well as in tuberculin skin testing of individuals used as an auxiliary tool in diagnosing tuberculosis. Taking this information into consideration is especially important when there is increasing BCG revaccination coverage
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Test tuberculinique
/
Vaccin BCG
Type d'étude:
Etude diagnostique
/
Recherche qualitative
/
Facteurs de risque
Limites du sujet:
Adolescent
/
Enfant
/
Femelle
/
Humains
/
Mâle
Pays comme sujet:
Amérique du Sud
/
Brésil
langue:
Anglais
Texte intégral:
Rev. panam. salud pública
Thème du journal:
Santé publique
Année:
2003
Type:
Article
Pays d'affiliation:
Brésil
/
Royaume-Uni
Institution/Pays d'affiliation:
London University/GB
/
Universidade Federal da Bahia/BR
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