Useful Information

11 June 2004

Dear Doctor,

A local case of Japanese Encephalitis in 2004

On 10 June 2004, the Centre for Health Protection (CHP) of Department of Health (DH) confirmed a local case of Japanese encephalitis (JE). This is the first JE case in 2004.

The patient was a 29-year-old Indonesian female domestic helper. She had onset of neurological symptoms on 29 May and was admitted to Princess Margaret Hospital on 2 June. Her condition deteriorated and she passed away on 7 June. Serological tests on JE confirmed a significant rise in titre from 1:160 to 1:5120. As the patient did not travel outside Hong Kong in the 2 weeks before onset of illness, this is classified as a local case. Investigations were initiated at her residence Kau Wa Keng of Kwai Chung (FE?|sh) to determine the source and extent of infection. A JE alert system is being set up between hospitals to monitor the occurrence of viral encephalitis cases in the coming 3 weeks.

During 1997-2003 in Hong Kong, there were 5 JE cases reported, including 1 local case in 2003 and 4 imported cases (1 in 1997, 1 in 2001, and 2 in 2002). The incubation period of JE is usually 4 to 14 days. The disease may begin with non-specific prodromal symptoms lasting several days, followed by acute onset of high fever, severe headache, vomiting, photophobia, drowsiness, meningism and convulsion. Many infections are asymptomatic. Case fatality rate of symptomatic cases of JE ranges from 5% to 35%. Neurological sequelae may occur in up to 70% of the survivors of symptomatic JE infections. For more information on JE, please go to This link will open in a new windowhttp://www.chp.gov.hk/en/content/9/24/28.html.

If you encounter patients with signs and symptoms suggestive of JE, especially those living in the neighbouring areas (within 2 km) of the JE patient, please report to the central notification office of the Surveillance and Epidemiology Branch (SEB) under the CHP. The contact details of the SEB central notification office are:

Thank you for your attention.