Rare case of Japanese encephalitis sparks medical alert An Indonesian domestic helper who worked in Kwai Chung has died from Japanese encephalitis, prompting an alert for anyone showing symptoms to seek urgent medical advice. The mosquito-borne disease, which attacks the membranes of the brain, was confirmed yesterday after tests by the Centre for Health Protection, said its communicable diseases consultant, Thomas Tsang Ho-fai. The 29-year-old woman, who worked for a family of seven at Kau Wa Keng San Tsuen, first showed symptoms on May 29. She was admitted to Princess Margaret Hospital on June 2 but died five days later. The virus is transmitted to humans through a bite of the Culex mosquito, which carries the virus after feeding on infected pigs. There are no pig farms in the area. The mosquitoes are abundant during the summer. No family members at the flat where the maid worked have shown symptoms of the viral infection but they have been put under medical surveillance. The centre is also checking on neighbours and conducting blood tests on them. Dr Tsang urged people living in Kwai Chung, Lai King, Mei Foo and Lai Chi Kok to call the centre's hotline, 2575 1848, so staff can advise them if they have symptoms. The virus has an incubation period of five to 15 days; symptoms include high fever, neck stiffness, dizziness and impaired mental state. Hong Kong has so far reported seven cases of Japanese encephalitis, three of which have been acquired locally. There was one other fatal case in 1996. 'Although the incidence is low, Japanese encephalitis does have a high fatality rate and can reach 20 to 50 per cent,' Dr Tsang said. There is no specific treatment for Japanese encephalitis, but a vaccine is available. The centre also announced yesterday that a 26-year-old Indonesian domestic helper who lived in Tung Chung died of viral encephalitis on June 1 at Princess Margaret Hospital. The woman was not suffering from Japanese encephalitis. A 24-year-old Hong Kong woman in Tsing Yi was last night critically ill at the same hospital with viral encephalitis, he added. So far there have been 70 viral encephalitis cases this year in Hong Kong. Wong Sai-yin, assistant professor of the department of microbiology at the University of Hong Kong, said people should keep their living environment dry and prevent mosquito breeding places. Dr Wong said the disease was already endemic in Guangdong and other mainland cities as well as Southeast Asian countries.