Published Date: 2014-07-22 17:53:41
Subject: PRO/AH/EDR> Japanese encephalitis – China: (HK)
Archive Number: 20140722.2628554
JAPANESE ENCEPHALITIS – CHINA: (HONG KONG)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Tue 22 Jul 2014
Source: South China Morning Post [edited]
Health authorities have confirmed the city’s 2nd case of Japanese encephalitis this year  and are not ruling out the possibility of more instances over the summer. Blood and sputum tests on a 35 year old woman residing at Ching Nga Court on Yuen Long’s Tai Shu Ha Road East tested positive for the virus on Saturday [19 Jul 2014]. She is now in a stable condition at Tuen Mun Hospital.
The woman reported feeling ill on 4 Jul  after coming down with a fever, headaches, and bouts of vomiting. She did not travel out of Hong Kong in the 2 weeks before falling sick, but reported being bitten by mosquitoes in Yuen Long, the Centre for Health Protection said yesterday [21 Jul 2014]. The woman visited a private doctor but was subsequently admitted to hospital after developing another fever 10 days later.
This is the 2nd case of Japanese encephalitis [virus infection] to occur in the Yuen Long district this year . A 26 year old from Tin Shui Wai was infected with the virus last month [June 2014].
The large bodies of water such as ponds and marshes abundant across Yuen Long are prime breeding grounds for _Culex_ mosquitoes, the genus of the pest that carries and transmits the virus.
Yuen Ming-chi, the Food and Environmental Hygiene Department’s officer in charge of pest control, said one risk factor could have been the 4 pig farms located near the victim’s home. The mosquitoborne virus is often found in pigs [amplifying hosts] and wild water birds [reservoir hosts]. “Mosquito prevention and extermination works have been deployed to the area in and around Ching Nga Court,” he said.
Dr Chuang Shuk-kwan, the centre’s consultant for community medicine, said the rainy season could bring about more cases. “It is still summertime, and there will still be [more] rainfall … There is a risk of further cases, but it is difficult to predict how many more,” she said. “Preventing and controlling the spread of Japanese encephalitis will require mosquito extermination work.”
There were 6 reported cases of Japanese encephalitis in Hong Kong last year . Of these, 2 of them involved people who contracted the disease locally; 3 had picked up the virus overseas, and in the 6th case, the source is still unknown. The 2 local cases reported last year involved residents of Tin Shui Wai.
[byline: Ernest Kao]
ProMED-mail from HealthMap Alerts
[As the report above indicates, there have been sporadic cases of Japanese encephalitis virus infection [JEV] in Hong Kong. There were 2 previous cases in Hong Kong this year (2013) that are positive for JEV infection (see ProMED-mail archive no. 20130723.1840352). The virus is endemic in large areas of Asia, including Japan and China. Because Hong Kong is well within the geographic distribution of JEV, it would not be surprising to see additional cases occur occasionally. Individuals living in, or traveling to, JEV endemic areas are well advised to follow precautions to avoid mosquito bites. JEV vaccine is available in China, but there is no mention about the immunization status of the above cases.