The Centre for Health Protection (CHP) of the Department of Health is investigating today (August 21) two additional local cases of dengue fever (DF) and again urged the public to maintain strict environmental hygiene, mosquito control and personal protective measures both locally and during travel.

     The first additional case involves a 59-year-old male patient with good past health, who developed fever, headache, retro-orbital pain, myalgia and arthralgia since August 17. He sought medical attention at the Accident and Emergency Department (AED) of St John Hospital as well as Queen Mary Hospital (QMH) on August 20. He is admitted to QMH and has all along been in a stable condition. His blood sample tested positive for dengue virus serotype 1 upon laboratory testing.

     Initial enquiries revealed that the patient lives alone in San Hing Street in Cheung Chau and recalled history of mosquito bite in Fa Peng Road in Cheung Chau. During the incubation period, the patient had travelled to Shunde and Guangzhou in Guangdong. This case is tentatively classified as a local case.

     The second case involves a 43-year-old female patient with good past health, who developed fever, myalgia, arthralgia and rash since August 14. She was admitted to Queen Elizabeth Hospital for treatment on August 20. 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 Chuk Yuen (South) Estate in Wong Tai Sin. She had no travel history during the incubation period but had visited Lion Rock Park. She recalled history of recent mosquito bite.

     Her home contact has remained asymptomatic and has been put under medical surveillance.

     For the remaining two cases among the four local cases of DF recorded on August 18, further laboratory testing revealed that the genetic sequence of the virus of one case (69-year-old female patient) was highly similar to the virus from the majority of Lion Rock Park cases earlier, while the virus of the other case (61-year-old male patient) could not be sequenced.

     "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. Epidemiological investigations are ongoing," a spokesman for the CHP said.

     "The CHP, together with the FEHD, will conduct a health talk at 1/F of Cheung Chau Municipal Services Building at 11am this Thursday (August 23) and another health talk at Chuk Yuen Estate Community Centre at 8pm this Friday (August 24) to deliver health advice. The CHP has also provided information and details of geographical distribution on the local DF cases on the CHP's designated webpage for DF to facilitate handy access of information for the public," the spokesman said.

     "The CHP appeals to members of the public not to visit Lion Rock Park during the closure period in order to prevent contracting DF. People who had visited Lion Rock Park are advised to apply insect repellent for 14 days upon their last visit, and those with DF symptoms should seek medical advice as early as possible," 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, Cheung Chau (Hillside Road, Tsan Tuen Road, Fa Peng Road and San Hing Street), 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.

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

     These are the 17th to 18th local cases recorded this year. Excluding the local cases, as of noon today, 61 imported cases had been recorded in 2018. The cases were mainly imported from Thailand (26), the Philippines (12) 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.

Ends/Tuesday, August 21, 2018
Issued at HKT 21:38

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