The Centre for Health protection is monitoring a suspected case of Japanese encephalitis involving a 45-year-old man living in Palm Springs, Yuen Long. 

The centre is performing lab tests to confirm the diagnosis.

As a precautionary measure, the Food & Environmental Hygiene Department has carried out vector surveys and mosquito control measures near the patient's residence.

Man became ill on June 8

The man, a local resident, developed fever, headache and drowsiness on June 8. He was admitted to North District Hospital and was later transferred to Pamela Youde Nethersole Eastern Hospital where he is in critical condition. 

The patient did not travel outside Hong Kong in the past three months. 

The centre's medical staff visited the patient's four household contacts and put them under medical surveillance. They did not have any symptoms of the illness.

The staff also inspected their home.

Results of the laboratory tests are expected within a day. Relevant departments are taking action in the event this case is confirmed. 

Seven cases reported since 1992

From 1992 to 2004, there have been seven sporadic cases reported in Hong Kong - one local case in 1996, one imported case in 1997, one imported case in 2001, two imported cases in 2002, one local case in 2003 and one local case so far this year.

Japanese encephalitis is transmitted by Culicine mosquitoes living mainly in rural areas. The mosquitoes breed in water-logged fields and marshes. Removing stagnant water helps prevent mosquito breeding.