Transmission of tuberculosis from a seven-year-old child in a Sydney school

Objectives: To determine whether a 7-year-old child with extrapulmonary and pulmonary tuberculosis (TB) and direct smear positive sputum for acid-fast bacilli was infectious to home and school contacts, and to ascertain poten tial adult sources of infection for these contacts. Methods: Contact tracing by Mantoux testing was conducted on 220 children a t a primary school and after-school care facility, and 59 selected adults c onsidered potential sources of infection. Results: The participation rate for the children was 98% and 92% for the ad ults. Mantoux positivity (induration greater than or equal to 10 mm, or gre ater than or equal to 15 mm with previous BCG) among children was 13% at th e school (anticipated rate 2-3%), 26% among school staff, and 7% among chil dren at the after-school care centre where the index case attended. One exp osed adult hospital staff member converted from Mantoux negative to positiv e. No other cases of TB disease were detected among children or adults test ed. Conclusion: Although spread of TB from children to others is rare, the find ings of this investigation indicate that transmission of TB from a young ch ild to other children and an adult may have occurred, and that sputum testi ng and contact tracing for sputum smear positive children should be conside red.