The figures are high, with more than 7,200 cases in 2001, despite measures taken to prevent it from spreading, such as the introduction of a vaccination for all newborn babies since 1952.

Nearly 58 in every 100,000 people aged between 15 and 19 suffered from TB in 2000 - a sharp increase, compared with the figure for 10- to 14-year-olds. There were only nine sufferers in every 100,000 people in the younger group. Reports by age for last year have not yet been released.

TB is caused by an organism called Mycobacterium tuberculosis. Pulmonary tuberculosis is the most common type which affects the lungs.

It is spread through direct contact with patients' nasal or throat secretions, and is also airborne and can be caught when someone infected with TB coughs or sneezes.

To reduce the chance of TB infection, all newborn babies in Hong Kong are given a Bacilli Calmette-Guerin (BCG) vaccination shortly after birth. However, this provides only partial protection. The vaccine is considered efficacious in young children, but not in adults.

The best weapon is our own defence system, according to the Department of Health's Central Health Education Unit. This can be achieved by paying attention to personal hygiene, adopting a healthy lifestyle and eating a well-balanced diet, getting adequate rest and exercise, not smoking or drinking alcohol, keeping the environment clean and avoiding poorly ventilated areas.

TB patients suffer night sweats, fatigue, weight loss, persistent coughs and have blood in the sputum. But some show no obvious symptoms.

People with TB can be cured. A complete course of treatment takes around six months and must be finished, once started. Patients should follow doctors' instructions and take their medication under the supervision of nurses. If the course of treatment is not completed, the germs may develop a resistance to the drugs, and complete recovery will be difficult.

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