The Centre for Health Protection urges people to guard against mosquito-transmitted diseases after lab tests confirmed a second case of Japanese encephalitis this year, in a 15-year-old boy living in Kwai Chung.

The boy developed fever, headache, vomiting and a stiff neck on August 13 and was admitted to Yan Chai Hospital on August 15. He has recovered and was discharged on August 24.

The lab tests were positive for Japanese encephalitis, a viral disease transmitted by mosquito bites.

The boy had joined a tour to Guizhou from July 23 to 29, and the centre is contacting his travel companions. Three people living with him have not shown any symptoms of the illness and are under medical surveillance.

There was one imported Japanese encephalitis case in 2001, two imported cases in 2002, one local case in 2003 and five local cases in 2004. One local and one imported case were reported in 2005 and none in 2006.

Prevention tips

Culicine mosquitoes - which breed mainly in water-logged fields, marshes, ditches and small stable collections of water around cultivated fields - transmit the virus after biting pigs and wild birds infected with it.

People living in or visiting rural areas in particular are reminded to protect themselves by wearing long-sleeved clothes and trousers, using insect repellent and using mosquito screens or nets when a room is inside is not air-conditioned.

More details on preventive measures are available here and here.