The need to implement effective new entrant tuberculosis screening in children: Evidence from school 'outbreak'

Background: In January 2013 a secondary school pupil in London was diagnosed with sputum-smear positive pulmonary tuberculosis (TB) and was started on treatment. In April 2013 another pupil in the same year group at the same school was diagnosed with sputum-smear positive pulmonary TB. Pupils in the same year were then screened for tuberculosis. Methods: Interferon gamma release assay (IGRA) testing was used to identify those infected with tuberculosis. Further tests were conducted to identify contacts with active tuberculosis disease and specimens were sent for genotypic testing. Results: Two hundred and seventy-one contacts were identified, of whom 202 (75%) attended for screening. Two further cases of culture confirmed TB were diagnosed and six cases of latent TB were diagnosed. Molecular typing of the four TB cases revealed three genotypically unrelated strains. Conclusions: The genotyping has helped challenge widely held assumptions that TB cases detected via contact tracing in schools indicate in-school transmission. Routine screening of children newly arrived from TB endemic countries should be proactively carried out, as recommended by National Institute for Clinical Excellence (NICE) guidelines, in order to avoid preventable morbidity from TB disease in children.