Press Release

Update on number of dengue fever cases

23 October 2015

The Centre for Health Protection (CHP) of the Department of Health (DH) today (October 23) reported the latest 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 both locally and during travel.

From October 9 to 22, four additional confirmed cases were recorded. All were imported cases in which two patients had been in the Philippines and one each was in Vietnam and Myanmar during the incubation period.

As of yesterday (October 22), a total of 90 cases had been confirmed this year, comprising a local case, 88 imported cases and one unclassified case. Of note, the number of cases recorded so far in 2015 is the highest when compared with the corresponding periods in the past decade, from 22 to 87 from 2005 to 2014.

The CHP has been closely monitoring the latest dengue situation in neighbouring and overseas areas, and the dengue activity in southern Taiwan remains high. According to the health authority of Taiwan, to date, 26 660 local cases of DF, including 122 deaths, have been recorded since this summer and nearly all (98.7 per cent) were in Tainan, Kaohsiung and Pingtung in southern Taiwan.

"As the dengue activity in southern Taiwan remains high, the public are reminded to take anti-mosquito measures when travelling to the area, and to Southeast Asian countries, in order to prevent DF," a spokesman for the CHP said.

In Guangdong, local cases have been recorded in Chaozhou, Zhongshan, Foshan, Guangzhou, Dongguan, Shantou, Shenzhen, Jieyang, Jiangmen, Maoming and Yunfu. The first local case this year occurred around two months earlier than that in 2014. Regarding popular tourist attractions in Asia, 96 222 DF cases have been recorded in Malaysia so far this year, 95 283 in Thailand, 8 211 in Singapore and 239 in Japan. In the Americas, 1 416 179 were filed in Brazil and 139 966 in Mexico.

"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," the spokesman said.

"As there is no dengue vaccine now available and locally registered, strict environmental hygiene, mosquito control and personal protective measures remain the most effective means against DF both locally and during travel," the spokesman added.

Travellers are urged to be alert to the dengue risk of travel destinations 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 during outdoor activities;
• Before the trip, arrange a 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 the 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.

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