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[BCG test reaction in previously BCG Moreaux-Rio de Janeiro-vaccinated healthy children]
1Escola Paulista de Medicina (EPM), São Paulo, SP, Brazil.
Insights
The Bacillus Calmette-Guérin (BCG) test reaction in vaccinated children shows decreasing size over time. A cutoff of 15mm improves specificity for detecting tuberculosis in pediatric practice.
Area of Science:
- Pediatric immunology
- Vaccine efficacy studies
- Diagnostic test evaluation
Context:
- Evaluating the utility of the BCG test in non-tuberculous children aged 2-11 years.
- Assessing the BCG test's performance in individuals vaccinated in infancy.
- Understanding the long-term immune response post-BCG vaccination.
Purpose:
- To critically evaluate the usefulness of the BCG test in pediatric practice.
- To determine the reliability of the BCG test for diagnosing tuberculosis in vaccinated children.
- To identify optimal reaction thresholds for accurate interpretation.
Summary:
- The BCG test reaction profile in vaccinated children (n=91) exhibited a unimodal distribution (3-17mm, median 6mm).
- Reaction size diminishes with time post-vaccination.
- A cutoff of >10mm may yield significant false positives; >15mm enhances specificity for tuberculous disease.
Impact:
- Provides evidence-based recommendations for interpreting BCG test results in vaccinated children.
- Highlights the need for age-appropriate diagnostic criteria in pediatric tuberculosis screening.
- Contributes to optimizing the use of immunological tests in clinical practice.
Abstract:
BCG-test reaction was carried out in 91 non-tuberculous children between 2 and 11 years old, who had received BCG vaccination during the first six months of life to critically evaluate the usefulness of this test in Pediatric practice. The BCG-test profile of the vaccinated group was shown to have a unimodal distribution, varying from 3 to 17 millimeters, with a median of 6 millimeters. It was demonstrated that the degree of reaction decreases with time. Nevertheless, false-positives could be expected in a significant percentage when reactions larger than 10 millimeters are considered as a cutoff. The specificity can be increased using only reactions with diameter equal or greater than 15 millimeters as an indicator of tuberculous disease.
