Health officials have placed a teenage tuberculosis patient under quarantine after he failed to turn up for treatment as required.

The secondary school student, 18, sought treatment at Queen Elizabeth Hospital on May 13 due to shortness of breath, fever, weight loss and a persistent cough, sometimes coughing up blood. He left hospital on Sunday against advice from doctors and was told to go to a government chest clinic for follow up.

The patient attended one session the next day and received one dose of anti-tuberculosis treatment, but didn't continue his treatment as scheduled.

On Friday, the Centre for Health Protection (CHP) issued an isolation order, and the teenager was taken to Princess Margaret Hospital.

"Since the patient has only received anti-TB treatment for a short period of time, discontinuing the treatment would worsen the infection, increase the risk of transmission and emergence of drug-resistant TB, posing a public health threat," a government statement said.

"Those diagnosed with TB should follow their doctor's instructions and complete the entire course of anti-TB treatment."

Health officials also said the student had not been vaccinated under the local immunisation programme.

The CHP said it was arranging screening for teachers, staff and students of the same grade at his school.

No other cases have been reported so far.