[Trends in the prevalence of tuberculosis among six-year-olds in Albacete (Spain)]

[Prevalence and annual risk of tuberculosis infection in the school population aged 7 years old in Ceuta (Spain)]

OBJECTIVE

To determine the prevalence of tuberculosis infection and annual risk of infection in the school population of Ceuta.

METHOD

A cross-sectional study was conducted. A tuberculin test (2UT RT-23 Tween 80) was given to 7-year-old schoolchildren in Ceuta in 2008. A positive result was considered as an induration of ≥5 mm at 72 hours in unvaccinated children.

RESULTS

A total of 612 children were studied. The prevalence of tuberculosis infection was 0.98% (95% confidence interval with a 2.5% margin of error). The distribution showed differences among three health areas, and was greatest in the most deprived area (2.07%). The annual risk of infection was 0.15%.

CONCLUSIONS

According to the most recent studies, the prevalence of tuberculosis infection in Ceuta is one of the highest of Spain. Our results do not agree with the epidemiological data for tuberculosis in Ceuta, which also includes imported cases.

[Prevalence of tuberculosis infection in BCG-vaccinated and unvaccinated Mediterranean schoolchildren]

OBJECTIVE

To determine the prevalence of tuberculous infection in schoolchildren in the province of Malaga, Spain, and to evaluate its relation to sociodemographic variables.

POPULATION AND METHODS

Tuberculin skin tests were used to screen 6-year-olds in their first year of primary school in this cross-sectional study of the prevalence of infection, with calculation of 95% confidence interval (CI). Children who had not been vaccinated against tuberculosis at birth were considered to have a positive test result if they had an induration of >or=5 mm. Those who had received bacillus Calmette-Guerin (BCG) vaccination at birth were considered to have a positive test result if they had an induration size of >10 mm or >15 mm, depending on whether they came from a country with a high or low prevalence of tuberculosis, respectively.

RESULTS

The prevalence of infection in the group of unvaccinated children was 1.16% (95% CI, 0.69%-1.63%). No statistically significant differences were found for any of the sociodemographic variables analyzed. The prevalence of infection in the BCG-vaccinated children was 6.66% (95% CI, 5.55%-7.77%).

CONCLUSIONS

The prevalence of tuberculosis infection in our area is slightly higher than that reported after other studies conducted in Spain. This could indicate that tuberculosis continues to be a public health problem in the province of Malaga. Infection in the subgroup of BCG-vaccinated children, however, was lower than that observed in studies of immigrants in Spain who had been immunized at birth. This is probably because the majority of immigrants in our area come from countries with a low incidence of tuberculosis.

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.

La prueba de tuberculina en los controles del niño sano. ¿Debemos cambiar nuestra práctica?

BACKGROUND

The Healthy Child Program and the Preventive Activities and Health Promotion Program involve systematic tuberculin skin testing at distinct ages according to different programs, with variable evaluation of its effectiveness.

OBJECTIVE

To evaluate the tuberculin skin test performed in healthy children within the ongoing basic health program in order to determine whether our activity is effective in detecting latent tuberculin infection.

MATERIAL AND METHODS

A prospective observational study was performed.

POPULATION

Mantoux test performed in children aged 15 months to 14 years during regular health examinations in 22 primary care pediatric clinics over a 12-month period in southern Pontevedra in Spain (catchment population 300,613 inhabitants according to the official census data in January 2003, with 472,444 health cards). Descriptive study and univariate analysis were carried out.

RESULTS

We studied 2,530 children with a mean age of 51.25 months (95 % CI: 49.38-53.13). Eight positive Mantoux tests were registered (0.36 %). There were three positive results in children aged less than 3 years, two positive results in children aged between 4 and 9 years old (all were immigrants) and the remaining positive results were registered in children between 10 and 14 years of age.

CONCLUSIONS

Given that the tuberculin skin test is a good screening test despite its limitations in the control of latent tuberculin infection in children, its indications should be adjusted to ever-changing epidemiological characteristics. According to the results obtained in this study and considering the prevalence of tuberculosis in our environment, we propose that the systematic application of the Mantoux test be discontinued except in children from countries with a high incidence of this disease or risk factors. However, we also recommend that systematic Mantoux testing in adolescence (12-14 years of age) be maintained, when vaccination and various medical examinations are carried out. Epidemiological studies in this age group should simultaneously be performed.