CHP investigates four additional local cases of dengue fever

     The Centre for Health Protection (CHP) of the Department of Health is investigating today (August 17) four additional local cases of dengue fever (DF) and announces the latest laboratory investigation results on the three 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.
 
     Further laboratory investigation revealed that the genetic sequences of the virus from the three local cases of DF announced yesterday are identical to other three cases confirmed on August 15.

     Regarding the additional cases recorded today, the first case involves a 70-year-old male patient with good past health, who developed fever, headache, myalgia and arthralgia since August 8 and skin rash on August 13. He sought medical attention at the Accident and Emergency Department (AED) of United Christian Hospital on August 15 and was admitted for treatment on the same today. He has all along been in a stable condition and his blood sample tested positive for dengue virus serotype 1 upon laboratory testing.

     Initial enquiries revealed that the patient lives in Tung Tau (II) Estate in Wong Tai Sin. The patient had gone hiking at Lion Rock Park frequently during the incubation period. However, he did not recall any mosquito bites.
 
     The second case involves a 55-year-old male patient with good past health, who developed fever, headache, myalgia, arthralgia and skin rash since August 9. He was admitted to Queen Elizabeth Hospital (QEH) for treatment yesterday. He has all along been in a stable condition and his blood sample tested positive for dengue virus serotype 1 upon laboratory testing.

     Initial enquiries revealed that the patient lives in Tin Ma Court in Wong Tai Sin. The patient went to the Lion Rock Park for walk frequently during the incubation period and recalled history of mosquito bite in the Park.

        The third case involves a 71-year-old male patient with underlying illnesses, who developed fever, headache, myalgia, arthralgia, nausea and anorexia since August 10. He sought medical attention at the AED of QEH yesterday and was admitted on the same day. He has all along been in a stable condition and his blood sample tested positive for dengue virus serotype 1 upon laboratory testing.

     Initial enquiries revealed that the patient lives in Tsui Chuk Garden in Wong Tai Sin. The patient went to the Lion Rock Park frequently for exercise during the incubation period and recalled history of mosquito bite in the Park.
 
     The fourth case involves a 40-year-old female patient with good past health, who developed fever and myalgia since August 14. She sought medical attention at the AED of QEH on August 15 and was admitted on the same day. She has all along been in a stable condition and her blood sample tested positive for dengue virus serotype 1 upon laboratory testing.

     Initial enquiries revealed that the patient lives in Shanghai Street in Yau Ma Tei. The patient had visited the barbecue area at Lion Rock Park for barbecue 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 is today continuing the epidemiological investigations into the seven local cases of DF announced earlier. CHP officers has conducted a site visit to Lion Rock Park and held a health talk together with FEHD officers today to provide health advice for the workers of the Park. The CHP has also conducted questionnaire surveys. As of 5pm today, 15 questionnaires involving 16 persons had been collected. Among them, two reported history of DF symptoms and 10 took blood for testing," the spokesman said.
 
     "CHP Officers have also conducted a site visit today to the patients' home in Portland Street in Yau Ma Tei as announced yesterday and carried out active case finding. As of 5pm today, three questionnaires involving 11 persons had been collected. Among them, none reported DF symptoms. No abnormalities have been detected so far. 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."
 
    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 and Shanghai Street 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, 54 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 eighth to 11th local cases recorded this year. Separately, from August 10 to 17, the CHP recorded two confirmed imported DF cases. The patients had been to Indonesia and India (one case each) during the incubation period. Excluding the local cases, as of today, 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 News, tips 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.