CHP investigates four additional local cases of dengue fever

     The Centre for Health Protection (CHP) of the Department of Health is investigating today (August 18) four additional local cases of dengue fever (DF) and announces the latest laboratory investigation results on the four local cases of DF confirmed yesterday. The CHP again urged the public to maintain strict environmental hygiene, mosquito control and personal protective measures both locally and during travel.

     "The CHP appeals to members of the public who had visited Lion Rock Park to apply insect repellent for 14 days upon their last visit to prevent possible secondary spread of the disease. In addition, any visit to Lion Rock Park during closure is not recommended in order to prevent contracting DF. Persons who have visited Lion Rock Park with DF symptoms should seek medical advice as early as possible," a spokesman for the CHP said.

     Among the four local cases of DF announced yesterday, further laboratory investigation revealed that the genetic sequences of the virus of two cases (71-year-old male patient and 40-year-old female patient) are identical to and one case (55-year-old male patient) is highly similar to other six cases confirmed earlier on. The virus of the remaining case cannot be sequenced.

     Regarding the additional cases recorded today, the first case involves a 55-year-old male patient with underlying illnesses, who developed fever, headache, cough and myalgia since August 10. He sought medical attention at Tsing Yi Town General Out-patient clinic and no hospitalisation is required. He has all along been in a stable condition and his blood sample tested positive for dengue virus upon laboratory testing.

     Initial enquiries revealed that the patient lives in Greenfield Garden in Tsing Yi. The patient works at Lion Rock Park and recalled history of mosquito bite in the Park.

     The second case involves a 63-year-old female patient with underlying illnesses, who developed sore throat, malaise and bilateral lower limbs skin rash since August 12. The patient was advised to seek medical attention. She has all along been in a stable condition. Her blood sample tested positive for dengue virus upon laboratory testing.

     Initial enquiries revealed that the patient lives in Chuk Yuen (South) Estate in Wong Tai Sin. The patient works at Lion Rock Park and recalled history of mosquito bite in the Park.

      The third case involves a 69-year-old female patient with underlying illnesses, who developed fever, headache, myalgia, arthralgia, rash over limbs, vomiting and diarrhoea since August 14. She sought medical attention at the Accident and Emergency Department of Queen Elizabeth Hospital on August 17 and was admitted for further treatment today. She has all along been in a stable condition and her blood sample tested positive for dengue virus upon laboratory testing.

     Initial enquiries revealed that the patient lives in Tin Wang Court in Wong Tai Sin. The patient went to Lion Rock Park for walk frequently during the incubation period but could not recall history of mosquito bite.

     The fourth case involves a 61-year-old male patient with underlying illnesses, who developed fever, headache, retro-orbital pain, arthralgia, myalgia and skin rash since August 12. He sought medical attention at the Our Lady of Maryknoll Hospital Family Medicine Clinic on August 15 and no hospitalisation is required. He has all along been in a stable condition and his blood sample tested positive for dengue virus upon laboratory testing.

     Initial enquiries revealed that the patient lives in Chuk Yuen (North) Estate in Wong Tai Sin. The patient went to Lion Rock Park for walk frequently during the incubation period and recalled history of mosquito bite in the Park.

     The home contacts of the four additional cases have remained asymptomatic and have been put under medical surveillance.

     "We are working closely with the Food and Environmental Hygiene Department (FEHD) to assess and prevent possible spread of infection. The FEHD's vector investigations, surveillance and control are ongoing. The Leisure and Cultural Services Department and Home Affairs Department are also following up on the matter. Epidemiological investigations are ongoing," the spokesman said.

     "The CHP and the FEHD held a health talk on DF last night at Wong Tai Sin Community Centre to deliver health advice. A total of 24 persons attended the talk and 5 took blood for testing. Besides, the CHP will hold health talks together with the FEHD at Kai Tak Community Hall (3pm) and Henry G. Leong Yaumatei Community Centre (noon) on next Monday," the spokesman said.

     Persons who have been to the vicinity of Wong Tai Sin (particularly Lion Rock Park), Kwai Shing West Estate, Clear Water Bay Second Beach, Hillside Road, Highland Park, Sai Tso Wan Recreation Ground, Wing Yiu Street, Tak Long Estate, Portland Street, Shanghai Street and Greenfield Garden with DF symptoms should call the CHP's hotline (2125 1122) for laboratory investigation or referral as appropriate. The hotline operates from 9am to 5.45pm daily. Since August 14 to 5pm today, 77 enquiries had been received.

     "We have informed the Guangdong and Macau health authorities to alert them to the latest situation," the spokesman added.

     These are the 12th to 15th local cases recorded this year. Excluding the local cases, as of yesterday, 57 imported cases had been recorded in 2018. The cases were mainly imported from Thailand (25), the Philippines (10) and Cambodia (seven).

     In the rainy season, the public should take heed of the following advice on mosquito control:
 

  • Thoroughly check all gully traps, roof gutters, surface channels and drains to prevent blockage;
  • Scrub and clean drains and surface channels with an alkaline detergent compound at least once a week to remove any deposited mosquito eggs;
  • Properly dispose of refuse, such as soft drink cans, empty bottles and boxes, in covered litter containers;
  • Completely change the water of flowers and plants at least once a week. The use of saucers should be avoided if possible;
  • Level irregular ground surfaces before the rainy season;
  • Avoid staying in shrubby areas; and
  • Take personal protective measures such as wearing light-coloured long-sleeved clothes and trousers and apply insect repellent containing DEET to clothing or uncovered areas of the body when doing outdoor activities.

     To reduce the risk of infections spread by mosquitoes, apart from general measures, travellers returning from affected areas should apply insect repellent for 14 days (DF) or at least 21 days (Zika Virus Infection) upon arrival in Hong Kong. If feeling unwell, seek medical advice promptly and provide travel details to the doctor. DEET-containing insect repellents are effective and the public should take heed of the tips below:
 

  • Read the label instructions carefully first;
  • Apply right before entering an area with risk of mosquito bites;
  • Apply on exposed skin and clothing;
  • Use DEET of up to 30 per cent for pregnant women and up to 10 per cent for children*;
  • Apply sunscreen first, then insect repellent; and
  • Re-apply only when needed and follow the instructions.

* For children who travel to countries or areas where mosquito-borne diseases are endemic or epidemic and where exposure is likely, those aged 2 months or above can use DEET-containing insect repellents with a DEET concentration of up to 30 per cent.

     The public should call 1823 in case of mosquito problems and may visit the DF pages of the CHP and its Travel Health Service, the latest Travel Health Newstips for using insect repellents, the CHP Facebook Page and YouTube Channel, and the FEHD's Guidebook on Control and Prevention of Mosquito Breeding for more information.