The Centre for Health Protection (CHP) of the Department of Health is today (June 28) investigating a local case of dengue fever (DF) which is epidemiologically linked with another local case announced earlier residing at Tin Shui (1) Estate in Tin Shui Wai. The CHP urged the public again to maintain strict environmental hygiene, mosquito control and personal protective measures both locally and during travel. Meanwhile, persons who have been to Tin Shui (1) Estate with DF symptoms should contact the CHP as soon as possible.
The new case involved a 44-year-old man, who presented with a fever on June 21. He attended the accident and emergency department (AED) of Tin Shui Wai Hospital (TSWH) on the next day (June 22) and no admission was required at that time. Later, he attended the AED of TSWH on June 25 again due to persistent fever, gum bleeding and skin rash, and was admitted for treatment on the same day. He is now in stable condition. His blood sample tested positive for dengue virus today upon laboratory testing.
Initial enquiries revealed that the patient lives in Shui Yee House, Tin Shui (1) Estate in Tin Shui Wai, which is next to the residence of another case (Shui Sing House, Tin Shui (1) Estate in Tin Shui Wai) involving a female patient announced earlier. As he had only left Hong Kong for a short period of time and otherwise stayed in Hong Kong for the whole incubation period, there is a higher probability that the case is locally acquired. Also, the residences of the two cases are close to each other, the CHP believes that they are epidemiologically linked. The CHP has inspected the residence of the male patient. The five home contacts of the male patient are currently asymptomatic and have been put under medical surveillance. The CHP will also provide blood screening for them.
In view of the previous case, the CHP has, together with the Food and Environmental Hygiene Department (FEHD), enhanced the anti-mosquito work in the vicinity of Tin Shui (1) Estate and places visited by the female patient. Such measures will continue until summer. Considering the symptoms onset date of the patient and the incubation period of DF (ranges from three to 14 days), the CHP does not rule out the possibility that the male patient had already been bitten by vector and infected before the enhanced anti-mosquito work. The CHP is highly concerned about the epidemiologically linked cases, and will continue to work closely with the FEHD and relevant government department in enhancing vector investigations, surveillance and control with a view to preventing a possible spread of infection.
The CHP has contacted over 4 500 residents from over 1 800 households of Tin Shui (1) Estate in Tin Shui Wai to follow up their health conditions in view of the first case. The CHP has enhanced the work of contacting relevant residents due to the two DF cases, and has contacted the households of Tin Shui (1) Estate again today. The CHP appeals to persons who have been to Tin Shui (1) Estate with DF symptoms to call the CHP's hotline (2125 2374) which will operate from 9am to 1pm tomorrow (June 29), this Sunday (June 30) and July 1, and will continue to operate from 9am to 5pm, Monday to Friday (excluding public holidays) starting July 2 for laboratory investigation or referral as appropriate. Furthermore, the CHP will hold a health talk jointly with the FEHD at 9pm tomorrow in the Tin Shui Community Centre, during which the CHP will also conduct free DF antibody tests for people in the district with relevant symptoms. Moreover, the CHP has contacted the respective District Council members to help disseminate and promote relevant health information to residents.
A spokesman for the CHP said, DF cannot be spread directly from human to human. Dengue virus encompasses four different serotypes, each of which can lead to DF and severe dengue. DF is clinically characterised by high fever, severe headache, pain behind the eyes, muscle and joint pain, nausea, vomiting, swollen lymph nodes and rash. The symptoms of first infection are usually mild. Once recovered, lifelong immunity to that serotype of dengue virus will develop. However, cross-immunity to the other three serotypes after recovery is only partial and temporary. Subsequent infections with other serotypes of dengue virus are more likely to result in severe dengue. Severe dengue is a severe and potentially fatal complication of DF.
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 and uncovered areas of the body when doing outdoor activities.
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
- Reapply 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 following pages for more information: the DF pages of the CHP and the Travel Health Service, the latest Travel Health News, tips for using insect repellents, and the CHP Facebook Page and YouTube Channel.
Follow this news feed: East Asia