The Centre for Health Protection (CHP) of the Department of Health is investigating this evening (August 4) a local case of Japanese encephalitis (JE) and again urged the public to avoid going to rural areas from dusk till dawn when the vector, which breeds in large water bodies such as rice paddies, is most active.

     According to the attending physician, the male patient aged 59 lives in Tin Shui (II) Estate, Tin Shui Wai. He has underlying illnesses. He has developed fever, headache, neck stiffness and vomiting since July 30 and attended Tin Shui Wai Hospital on July 31 and was subsequently admitted to Pok Oi Hospital for management on the same day. He has been in stable condition.

     His cerebrospinal fluid and blood samples tested positive for immunoglobulin M (IgM) antibodies against JE upon laboratory testing.

     Initial enquiries revealed that the patient had no travel history in the incubation period and his local movements before onset were mainly in Tin Shui Wai. His home contact has remained asymptomatic and has been put under medical surveillance.

     "As the patient is still febrile and unable to provide details of his exposure history, epidemiological investigations are ongoing," said the Controller of the CHP, Dr Wong Ka-hing.

     "While the patient lives in Tin Shui (II) Estate, it is in the same vicinity as Tin Shui (I) Estate where the patient of the local case reported on June 30 lives as well as Kingswood Villas where the blood donor related to the first local blood-borne case reported on July 20 lives. We are intensively working with the Food and Environmental Hygiene Department (FEHD) to prevent any further spread of infection. The FEHD and the Agriculture, Fisheries and Conservation Department have been informed for vector investigations, surveillance and control," Dr Wong said.

     Members of the public, especially residents and workers in Tin Shui Wai, should:
 

1. Avoid going to rural areas from dusk till dawn;
2. Apply DEET-containing insect repellents to exposed parts of the body and clothing; and
3. If fever and headache develop, especially quick onset of headache and high fever, seek medical attention early.

     Officers of the CHP will conduct a site visit and field investigations by questionnaire surveys at the patient's residence for active case finding and arranging blood tests. A health talk will be held jointly with the FEHD at noon on August 7 in Tin Shui Community Centre to deliver health advice to residents and the public.

     Persons who have been to the vicinity of Tin Shui Estate with JE symptoms should call the CHP's hotline (2125 1122) operating from 9am to 5.45pm this weekend for laboratory investigation or referral as appropriate.

     The Department of Health has informed the Guangdong and Macau health authorities of the case and will issue letters to local doctors and hospitals to alert them to the latest situation.

     This is the fourth JE case recorded in 2017 and all were locally acquired, three of which were mosquito-borne and one was blood-borne. Two (imported) and two (one local, one unclassified) cases were recorded in 2016 and 2015 respectively.

     JE is a mosquito-borne disease and the JE virus is transmitted by the bite of infected mosquitoes. The principal vector is called Culex tritaeniorhynchus. JE mainly occurs in rural and agricultural areas of Asia and the Western Pacific. The infected mosquito transmits the JE virus to humans and animals during biting. The mosquitoes breed where there is abundant water such as rice paddies and become infected by feeding on pigs and wild birds infected with the JE virus. Symptoms usually start around four to 14 days after being infected.

     To prevent JE, the public should take general measures to prevent mosquito bites and avoid going to rural areas from dusk till dawn when the mosquitoes are most active. Travellers to endemic areas should take special note.

     The public should:

     1. Wear loose, light-coloured, long-sleeved tops and trousers, and use DEET-containing insect repellent on exposed parts of the body and clothing;

     2. Take additional preventive measures in outdoor activities:

• Avoid using fragrant cosmetics or skin care products;
• Re-apply insect repellents according to instructions;

     3. Special notes during travel:

• If going to affected areas, arrange consultation with a doctor at least six weeks before travel, and have extra preventive measures to avoid mosquito bites;
• Vaccination is recommended for travellers who plan to stay one month or longer in endemic areas, particularly in rural areas, and for short-term (less than one month) travellers if they plan to have significant extensive outdoor or night-time exposure in rural areas during the transmission season of the disease;
• During travel in endemic rural areas, carry a portable bed net and apply permethrin (an insecticide) on it. Permethrin should not be applied to the skin. Seek medical attention promptly if feeling unwell; and
• Travellers feeling unwell, such as having fever, should seek medical advice promptly, and provide travel details to the doctor.

     The public may visit the CHP's JE page, tips for using insect repellents, Facebook Page, YouTube Channel and Travel Health Service and the FEHD's Guidebook on Control and Prevention of Mosquito Breeding for more information.

Ends/Friday, August 4, 2017
Issued at HKT 20:13

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