Remove stagnant water after rain to prevent dengue fever

     The Centre for Health Protection (CHP) of the Department of Health today (August 25) again urged the public to prevent the accumulation of stagnant water after rain to guard against mosquito-borne diseases including dengue fever (DF).

     "After a rainstorm and flooding, it is very important to quickly remove stagnant water in outdoor and household settings to stop mosquitoes from breeding. As a regular habit, the public should change the water in vases once a week, clear the water in saucers under potted plants every week, and ensure air-conditioner drip trays are free of stagnant water," a spokesman for the CHP said.

     From August 18 to 24, the CHP recorded three confirmed DF cases and the patients had been to Vietnam, the Philippines and Sri Lanka in the incubation period.

     As of August 24, the 67 imported cases in 2017 were mainly imported from Thailand (18), Sri Lanka (11) and the Philippines (10). One local case and another case with the source of infection under investigation have been recorded so far this year.

     Dengue remains endemic in some areas in Asia. In Guangdong, there were 171 cases in 2017 as of August 24. In Macau, there were six local cases as of August 22. In Asia, the latest figures of 2017 revealed that 31 512 cases have been recorded in Thailand, 1 877 in Singapore and 124 in Japan (since January 2). In the Americas, 6 546 cases were filed in Mexico.

     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 long trousers and apply insect repellent containing DEET to clothing or uncovered areas of the body when doing outdoor activities.

     To reduce the risk of infection 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 the 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.

     The public may refer to the CHP's tips for using insect repellents for details.

Ends/Friday, August 25, 2017
Issued at HKT 17:03