[Tuberculosis outbreak in a primary school: description and reflections on the value of gastric juice in the management of micro-epidemics]

Enferm Infecc Microbiol Clin. 2011 Feb;29(2):90-5. doi: 10.1016/j.eimc.2010.08.006. Epub 2011 Feb 25.
[Article in Spanish]


Aims: To describe a tuberculosis outbreak in a primary school arising from a secondary case.

Methods: Contact study and clinical study of exposed patients. Chest x-ray, gastric aspirate processing, and clinical evaluation of all children with a positive tuberculin skin test (TST) were recorded. Differential diagnosis between tuberculosis disease (TB) and latent tuberculosis infection (LTI).

Results: Two groups were identified: one of higher exposure to the index case (> 6 hours/day, for 3 months; n=17 children) and one of sporadic exposure (< 6 hours/day; n=82 children). Clinical or bacteriological criteria for diagnosing TB were seen in 6 out of 17 (35%) highly exposed children. Four of them had clinical or radiological criteria. The other two children were asymptomatic and had a normal chest X ray, but had a positive gastric aspirate for M. tuberculosis. The overall infection rate (TB+LTI) was 94%. One child out of 82 (1.2%) sporadically exposed children had radiological criteria for TB. Staff latent infection rate was 15%. Apart from the index case, there were no other tuberculosis cases among the staff. Relative risk (RR) of exposed children was 28.5 (95% CI: 3-250).

Conclusions: Prolonged exposure to a baciliferous patient may infect almost every child exposed in closed groups. It can also cause a high attack rate. In this scenario, routine gastric aspirate may be considered for all children with a positive TST. It may identify early subclinical TB with an increased probability of isolating the M. tuberculosis. The potential benefit of this isolation may reach the entire cohort.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Child, Preschool
  • Contact Tracing
  • Disease Outbreaks*
  • Down Syndrome / complications
  • Early Diagnosis
  • Environmental Exposure
  • Faculty
  • Female
  • Gastric Juice / microbiology*
  • Humans
  • Latent Tuberculosis / diagnosis
  • Latent Tuberculosis / diagnostic imaging
  • Latent Tuberculosis / epidemiology
  • Male
  • Mycobacterium tuberculosis / isolation & purification*
  • Radiography
  • Risk
  • Schools
  • Spain / epidemiology
  • Tuberculin Test
  • Tuberculosis / diagnosis
  • Tuberculosis / diagnostic imaging
  • Tuberculosis / epidemiology*
  • Tuberculosis / microbiology
  • Tuberculosis / transmission