Press Release

Update on number of dengue fever cases

26 June 2015

The Centre for Health Protection (CHP) of the Department of Health (DH) today (June 26) provided an update on the number of cases of dengue fever (DF) in Hong Kong, and again urged the public to maintain strict environmental hygiene, mosquito control and personal protective measures.

From June 19 to 25, three additional confirmed cases were recorded. The patients travelled to Cambodia (two cases) and India (one case) during the incubation period.

Among these three cases, epidemiological linkage was established among two patients who travelled together to Cambodia.

As of June 25, a total of 44 cases had been confirmed this year, comprising a local case and 43 imported cases.

"The number of cases recorded so far in 2015 is the highest compared with those of the corresponding period in the past 10 years (figures ranged from eight to 40 cases from 2005 to 2014). The number of cases is expected to increase as more people will travel during the summer vacation.

"Dengue viruses encompass four different serotypes. The symptoms of first infection with one serotype are usually mild, but subsequent infections with other serotypes even years afterward are more likely to result in severe dengue (also known as dengue haemorrhagic fever). Severe dengue is serious and potentially fatal. Without proper treatment, the case fatality rate of severe dengue can exceed 20 per cent," a spokesman for the CHP said.

"According to the World Health Organization, although clinical trials on humans for some dengue vaccine candidates are ongoing, none are now available and registered with any drug regulatory authorities. Strict environmental hygiene, mosquito control and personal protective measures hence remain the most effective means against DF both locally and during travel," the spokesman added.

Avoid mosquito bites

Travellers should stay alert to the DF risk before departing, and take heed of the preventive measures below:

• Wear loose, light-coloured, long-sleeved tops and trousers, and use DEET-containing insect repellent on exposed parts of the body and clothing;
• Avoid using fragrant cosmetics or skin care products and re-apply insect repellents according to instructions in outdoor activities;
• Before the trip, arrange travel health consultation at least six weeks in advance for any extra measures against mosquito bites; and
• During the trip, carry a portable bed net and apply permethrin (an insecticide) on it in rural endemic areas. Permethrin should not be applied to skin.

The incubation period of DF ranges from three to 14 days, commonly four to seven days. Anyone feeling unwell after returning from a trip should seek medical advice as soon as possible and provide travel details to their doctors.

Remove breeding sites

Members of the public should also prevent the accumulation of stagnant water and maintain good environmental hygiene:

• Change the water in vases once a week;
• Clear the water in saucers under potted plants every week;
• Cover water containers tightly;
• Ensure air-conditioner drip trays are free of stagnant water;
• Put all used cans and bottles into covered dustbins; and
• Store food and dispose of garbage properly.

Members of the public are reminded to make reports to the government departments via the hotline 1823 if mosquito problems are detected, and may visit the pages below for more information:

• The CHP's DF page (This link will open in a new windowwww.chp.gov.hk/en/view_content/38847.html);
• The DF page of the DH's Travel Health Service (This link will open in a new windowwww.travelhealth.gov.hk/english/popup/popup_dengue.html);
• The DH's latest Travel Health News (This link will open in a new windowwww.travelhealth.gov.hk/english/outbreaknews/outbreaknews.html);
• The CHP's tips for using insect repellents (This link will open in a new windowwww.chp.gov.hk/en/view_content/38927.html);
• The CHP Facebook Page (This link will open in a new windowwww.fb.com/CentreforHealthProtection);
• The CHP YouTube Channel (This link will open in a new windowwww.youtube.com/c/ChpGovHkChannel); and
• The FEHD's Guidebook on Control and Prevention of Mosquito Breeding (This link will open in a new windowwww.fehd.gov.hk/english/safefood/handbook_prev_mos_breeding.html).