A 57-year-old Tuen Mun resident has become the third person to come down with a meningococcal infection here this year, the Centre for Health Protection says. It urges people to guard against the disease.

Last Friday, the man started suffering from chills, headache and dizziness and was admitted to Tuen Mun Hospital on Saturday in stable condition. He had not travelled recently.

None of the people he lives with showed symptoms, but they have been given preventive drugs and are under medical surveillance.

All three meningococcal infection cases this year have been local ones. The numbers have been falling, from six in 2002 to three in 2003. There were four in 2004.

The infection is caused by a bacterium known as meningococcus, and it is transmitted by direct contact, including droplets from the nose and throat of infected people. The incubation varies from two to 10 days, and is commonly three to four days.

Severe infections may trigger shock, death

Severe illness may result when the bacteria invade the bloodstream, causing meningococcaemia, or the brain, causing meningitis.

When it invades the blood, typical symptoms are a sudden onset of fever, intense headache, bleeding below the skin and in mucous membranes, shock and even death.

Meningitis usually results in the sudden onset of intense headache, fever, nausea, vomiting, sensitivity to light, and a stiff neck. Early cases can be treated effectively with antibiotics.

Preventive measures

To prevent meningococcal infections, people are advised to:

* wash their hands frequently, and observe good personal and environmental hygiene;

* avoid crowded places;

* avoid close contact with patients who have fever or severe headaches; and

* cover their nose and mouth while sneezing or coughing, collecting fluids such as spittle and pleghm in a tissue, discarding it into a bin with a lid and washing their hands immediately.

Travellers returning from endemic areas should consult their doctor promptly if they feel unwell, and let her or him know your travel history.