Pupils at a West Sussex school are being screened for tuberculosis after a 12-year-old developed the disease.
Pupils are being given skin tests and health questionnaires
The Year Seven pupil at Littlehampton Community School was responding well to treatment, West Sussex council said.
The authority also said transmission of the illness to other people at the school was "extremely unlikely".
Pupils have been given skin tests and health questionnaires, and are being offered vaccinations. The council has sent information letters to parents.
Dr David Hagen, a consultant at the Health Protection Agency in Chichester, said: "Children with tuberculosis are rarely a source of infection in schools.
"We are working with NHS specialists to provide the school and family with the best possible advice."
Information from the council said the disease was usually spread through prolonged close contact with someone else who had TB of the lungs.
Measures taken at the school were in accordance with national guidelines advising that close contacts may need to be screened, a council statement said.