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(added on 2018/10/08)

Hong Kong dengue fever outbreak 2018 香港2018年的登革熱爆發

Data source: Food and Environmental Hygiene Department, Hong Kong Government.
Map created by CUHK SpatioEpi Group

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Between 14th August 2018 and 4th September 2018, 29 local dengue cases belonging to subtype 1 were reported in Hong Kong. Hong Kong is not an endemic city. The 2018 outbreak was the largest reported since 2001, with all cases either living in or have visited Cheung Chau (an outlying island) or Wong Tai Sin District. The last local dengue outbreak involving 3 cases occurred in the Mid-levels on Hong Kong Island in 2016 (Map: Local born dengue then and now).

In Hong Kong the main vector of dengue virus is Aedes albopictus (Asian tiger mosquito). The map shows the distribution of Ovitrap Index results of vector surveillance conducted in August 2018. Ovitrap index is the proportion of Aedes-positive ovitraps out of the total number of ovitraps in the surveillance areas. Results were classified into 4 levels to reflect the Aedes activities. In August 2018, the Ovitrap Index in Cheung Chau and Wong Tai Sin was classified as level 2 (5.01%-20%). At this level, the government’s strategy is to closely monitor the hygienic condition to stop mosquitos from breeding in the areas, conduct inception every week to identify and eliminate the breeding / potential breeding places.

Aedes albopictus is a weak flier that covers a distance of not more than 200 metres. The two inset maps show the resident locations of the reported cases and their 200-metre buffers in Wong Tai Sin (including Lion Rock Park) and Cheung Chau. The buffer zones of most cases were very close to each other, suggesting that the infections were related to a common source.

Currently, there is no effective vaccine against dengue virus infection. The best prevention is to reduce the number of breeding grounds of the Aedes mosquitoes by sealing up puddles of stagnant water, and avoid mosquito bites.

Data for the map were extracted from reports of Food and Environmental Hygiene Department and Centre for Health Protection, the Hong Kong Special Administrative Region.

在2018年8月14日至2018年9月4日期間,香港報告了29宗本地登革熱個案 (亞型1)。登革熱在香港並不是風土病。2018年是自2001年最大規模的本地登革熱爆發,其報告病例均住在或曾到訪長洲或黃大仙。對上一次本地登革熱爆發(3宗本地個案)是發生在2016年半山區 (地圖:土生土長登革熱)。

在香港,白紋伊蚊(亞洲虎蚊)是登革熱病毒的主要蚊媒。地圖顯示2018年8月誘蚊產卵器指數分佈,數值是監測地點發現白紋伊蚊滋生的誘蚊產卵器所佔百分比。誘蚊產卵器指數分類為4級,表示不同程度蚊患。 2018年8月長洲和黃大仙地區的誘蚊產卵器指數被分類為第2級 (5.01%-20%)。在這級別,政府密切監察衛生情況以阻止蚊子在該地區繁殖、每星期開展調查以確定蚊子的繁殖/潛在繁殖地點,並儘量徹底清除這些地方。