Hong Kong is unlikely to see an outbreak of Japanese encephalitis - despite the report of one local case this week. To be safe, the Department of Health will conduct a thorough risk assessment of the disease.  

More than 40 of the victim's neighbours in Fairview Park, Yuen Long have given blood samples, along with pig farmers from the area.

Initial results of blood tests should be available next week, the department's consultant Dr Thomas Tseng said in an interview with Metro Radio this morning.

The department will analyse the risk of contracting the disease for different sectors of the community before deciding on any measures to be taken, such as the need for vaccinations.

Japanese encephalitis vaccines generate side effects, Dr Tsang said, including skin problems, a drop in blood pressure and respiratory difficulties.

Most pigs, birds have antibodies

The Agriculture, Fisheries & Conservation Department's Deputy Director Liu Kwei-kin said pigs and birds are the main carriers of the disease's principal vector, the Culicine mosquito.

But more than 80% of pigs and birds have already developed antibodies so they would not be infected with the disease and transmit the virus. Therefore, Mr Liu noted, the vaccination may not be the most effective preventive measure.   

The department has stepped up pig farm inspections and has asked operators to maintain hygienic conditions. Anyone who violates regulations will be prosecuted by the Food & Environmental Hygiene Department, and their business licence will be cancelled.

Mr Liu said the mosquitoes are most active from 4am to 5am and at dusk. People should avoid the agricultural areas where they appear, and take precautions if they are in such areas.

Apart from regular prevention programmes, the Food & Environmental Hygiene Department has specifically conducted surveillance and control measures within the mosquitoes' two-kilometre flying limits.

The department has not found any Culicine mosquitoes around Fairview Park.    

To date, the health department's hotline 2961 8968 has received 218 calls about the disease, mostly from Fairview Park residents.