Childhood tuberculosis in a rural tropical area: risk factors

Pediatric tuberculosis at Beijing Children's Hospital: 2002-2010

OBJECTIVE

Our aim was to describe the patient characteristics, clinical-epidemiological profile, and treatment outcome of childhood tuberculosis (TB).

METHODS

A retrospective, descriptive study was undertaken of 1212 children aged 0 to 18 years admitted to Beijing Children's Hospital for the treatment of TB from January 2002 to December 2010. Statistical significance of category variables was evaluated by using Fisher's exact test.

RESULTS

Fifty-four percent of patients had extrapulmonary tuberculosis (EPTB), 38.8% had tuberculous meningitis, and 31.3% had disseminated TB. The last 2 types were defined as severe TB. Most patients with TB (81.6%) were cured or completed treatment. There were more patients aged <5 years and from rural areas with EPTB than with pulmonary tuberculosis. More severe cases of TB were found in patients aged <1 year than other less severe types of TB. Patients with no bacille Calmette-Guérin vaccination and a contact history at home had a significantly risk of contracting severe TB. Children aged <1 year and those with severe TB were more likely to have poor treatment outcomes (failed to improve or died). Among those with EPTB, only 61.3% and 61.1% had positive results on the purified protein derivative tuberculin skin test and chest radiograph, respectively.

CONCLUSIONS

In this referral hospital setting, more pediatric EPTB and severe TB patients were found among children aged <1 year. Age <1 year and having severe TB were risk factors for treatment failure. Thus, prevention and health care in pediatric TB should focus on both EPTB and severe TB.

The effect of Bacille Calmette-Guérin vaccine on tuberculin reactivity in indigenous children from communities with high prevalence of tuberculosis

The Bacille Calmette-Guérin (BCG) vaccine is the most widely used vaccine in the world, however it may cause problems for the appropriate interpretation of the tuberculin skin test (TST). We assessed the diagnostic value of latent infection in vaccinated and unvaccinated indigenous children from communities that have a very high prevalence of adult tuberculosis (TB). A total of 997 children under 15 years old and classified in age groups (0-1.9, 2-5, 6-9 and 10-15 years old) were randomly selected and given TSTs using the Mantoux technique. TST induration values of vaccinated children (n=724) were compared with those of children unvaccinated (n=273). BCG vaccination was not an important cause of false-positive TST, except in communities with a low prevalence of active TB. In conclusion, the results suggested that a history of BCG vaccination on TST+ response after 10 years of vaccination was statistically insignificant but whether at earlier age TST+ reflects most probably the degree of exposure to TB cases than BCG vaccination should be clarified in the future.