Tuberculosis infection and disease among schoolchildren: the influence of the HIV epidemic and of other factors

[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.

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

OBJECTIVES

To analyze the prevalence and evolution of tuberculous infection among 6-year-olds in Albacete and its relation to socioeconomic status of the family.

METHOD

A tuberculin test (2UT RT-23 Tween 80) was given to 6-year-old school children in and around Albacete in 1992 and 1999. We calculated the prevalence of tuberculosis and the relation to family socioeconomic level as assessed by the parents' level of education of the area of residence.

RESULTS

The tuberculin test was given to 2,783 children, 1,532 in 1992 (8% bacille-Calmette-Guerin-vaccinated) and 1,251 in 1999. The prevalence of tuberculosis infection among non-vaccinated children was 0.78% in 1992 (3.37% among vaccinated children, p = 0.012) and 0.72% in 1999. No significant differences between the two screenings were found except for the vaccinated and non-vaccinated children. The annual decline was 1.1% and the annual decrease in risk of tuberculosis infection was 0.12%. No significant differences related to level of parental education or area of residence were detected.

CONCLUSIONS

The prevalence of tuberculosis infection among 6-year-old school children in Albacete is low, although there is a very slight non-significant downward trend, which may be biased by the inclusion of bacille-Calmette-Guerin-vaccinated children. No differences related to family socioeconomic level were found.