Press Release

CHP investigates third local confirmed case of dengue fever

7 November 2014

The Controller of the Centre for Health Protection (CHP) of the Department of Health (DH), Dr Leung Ting-hung, announced tonight (November 7) the investigation into the third local confirmed case of dengue fever (DF) this year, and hence again urged the public to take precautions against mosquito-transmitted diseases.

The female patient, aged 36 with underlying illness, has presented with fever, headache and myalgia on November 2 and consulted a private doctor on November 5. She was then referred to the Accident and Emergency Department of Princess Margaret Hospital and was admitted for further management on the same day. She is now in stable condition with low grade fever.

The patient's blood sample was tested positive for dengue virus type 4 upon testing by the CHP's Public Health Laboratory Services Branch tonight.

Initial enquiries revealed that the patient lives in Chung Mei Lo Uk Village, Sheung Ko Tan Street, Tsing Yi, New Territories, where she recalled mosquito bites. She also recalled mosquito bites in Tsing Yi Northeast Park (TYNEP), Tsing Yi. She claimed no recent travel history both outside Hong Kong and to the vicinity of the construction site of MTR Sai Ying Pun Station during incubation period.

"We are highly concerned about this additional case. Based on current epidemiological findings, we suspect that there might be possible local transmission of dengue virus in other areas. The blood sample of the second local case was positive for dengue virus type 1, indicating more than one source of infection. We are working closely with the Food and Environmental Hygiene Department (FEHD) for all-out efforts to assess and prevent any spread of infection," Dr Leung remarked.

"Upon notification and laboratory confirmation, the CHP immediately commenced epidemiological investigation and promptly informed the FEHD for vector investigation and mosquito control. We have also informed the village office of Chung Mei Lo Uk Village, the Leisure and Cultural Services Department, and the Kwai Tsing District Office under the Home Affairs Department for their corresponding follow-up actions. The CHP's investigations and health education in the vicinity where the patient frequented are proceeding," Dr Leung said.

The patient's home contacts have remained asymptomatic so far and will be put under medical surveillance.

Officers of the CHP will conduct field investigation by surveys at the patient's residence and TYNEP for active case finding and arranging blood tests.

Persons who have been to Chung Mei Lo Uk Village and TYNEP with DF symptoms should call the CHP's public enquiry hotline (2125 1122) for laboratory investigation or referral to hospital as appropriate. The hotline will continue to operate from 9am to 6pm tomorrow (November 8) onwards.

A joint health talk with the FEHD will be held tomorrow to deliver health advice to the public.

"We will send letters to doctors and private hospitals to alert them of the case. We have also enhanced the surveillance of suspected DF cases in collaboration with public hospitals under the Hospital Authority, private hospitals and private doctors since October 25. Early referral and prompt control are critical to prevent further local spread of DF," Dr Leung added.

Including this case, to date, 100 DF cases (three local, 97 imported) were reported to the CHP this year. In 2013 and 2012, 103 and 53 cases were filed respectively and all were imported.

"In view of recent local confirmed cases and the DF activity remaining high in neighbouring areas, members of the public should heighten vigilance and take necessary precautions against mosquito-transmitted diseases both locally and during travel, particularly to DF-endemic areas. Mosquito control is of utmost importance to prevent the spread of DF," Dr Leung urged.

"At present, no effective vaccine for DF is available. Therefore, the best preventive measures are to avoid mosquito bites and to eliminate pockets of stagnant water that serve as breeding sites for mosquitoes," Dr Leung reminded.

Travellers should take the following preventive measures against DF:

• Wear loose, light-coloured, long-sleeved tops and trousers;
• Use DEET-containing insect repellent on exposed parts of the body and clothing; and
• Use mosquito screens or nets in rooms that are not air-conditioned.

Anyone feeling unwell after returning from a trip should seek medical advice as soon as possible and provide travel details to their doctor.

Members of the public should also avoid accumulation of stagnant water by:

• Disposing of all used cans and containers in covered rubbish bins;
• Changing the water in vases with plants once a week in order to prevent accumulation of stagnant water in the saucers;
• Covering all containers, wells and water storage points;
• Ensuring air-conditioner drip trays are free of stagnant water;
• Keeping all drains clear; and
• Paving all uneven ground.

The public may visit the CHP's DF page (This link will open in a new windowwww.chp.gov.hk/en/content/9/24/19.html) or that of the DH's Travel Health Service (This link will open in a new windowwww.travelhealth.gov.hk) for further information on DF and outbreaks in other areas. Travel agents, tour guides and travellers can check the latest news and advice on preventive measures.

More information on mosquito control can be found on the FEHD's website (This link will open in a new windowwww.fehd.gov.hk/english/safefood/handbook_prev_mos_breeding.html).

"Vector-borne diseases" is the theme of this year's World Health Day (WHD) of the World Health Organization. The public may visit the CHP's WHD Page (This link will open in a new windowwww.chp.gov.hk/en/view_content/28258.html) for more information.