Is tuberculin skin testing useful to diagnose latent tuberculosis in BCG-vaccinated children?
BACKGROUND
The tuberculin skin test (TST) is the most commonly used tool to detect infection with Mycobacterium tuberculosis. We sought to determine whether tuberculin skin testing is useful to detect latent infection by M. tuberculosis in a population that was vaccinated with the Bacille Calmette Guérin (BCG) vaccine.


METHODS
We performed a cross-sectional study during October 2000-February 2001, enrolling first and sixth graders from a random, stratified sample of public elementary schools in Orizaba, Veracruz, Mexico. We assessed the relationship between sociodemographic and epidemiological information, BCG scars, and TST reactivity.


RESULTS
There were 858 children enrolled in the study with a completed questionnaire and TST result. The prevalence of a positive TST result (> or =10 mm) was 12.4%. Controlling for BCG scar, age, and other characteristics, close contact with pulmonary tuberculosis patients (odds ratio 6.56, 95% confidence interval 2.05-21.07, P = 0.001) was independently associated with TST reactivity.


CONCLUSIONS
TST results helped identify children in a BCG-vaccinated population who had recent exposure to persons with pulmonary tuberculosis, were probably infected with M. tuberculosis, and could benefit from treatment for their latent tuberculosis infection.
García-Sancho F
Ma Cecilia
MC
Instituto Nacional de Salud Pública, Cerrada de Fray Pedro de Gante No. 50 Col. Sección XVI, Deleg. Tlalpan, C.P. 14000, Mexico, DF, Mexico.
García-García
Lourdes
L
Jiménez-Corona
Ma Eugenia
ME
Palacios-Martínez
Manuel
M
Ferreyra-Reyes
Leticia D
LD
Canizales-Quintero
Sergio
S
Cano-Arellano
Bulmaro
B
Ponce-de-León
Alfredo
A
Sifuentes-Osornio
José
J
Small
Peter
P
DeRiemer
Kathryn
K
D000293:Adolescent; D017677:Age Distribution; D001428:Bacterial Vaccines / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D009163:Mycobacterium bovis / Q000276:immunology*; D009169:Mycobacterium tuberculosis / Q000276:immunology; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D014374:Tuberculin Test / Q000379:methods*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology
D001428:Bacterial Vaccines