The government is investigating four more local cases of dengue fever. This means there have now been at least 23 cases of the virus in Hong Kong this year. This is the most number of reported cases since records began in 1994.
The four new cases involved three men and one woman aged between 18 and 71.
Laboratory blood tests showed they had contracted dengue fever. All four are in a stable condition.
Two of them live on Cheung Chau, while the 18-year-old man visited the island during the incubation period of the virus, which lasts between three and 14 days. The remaining patient, a 34 year-old man, lives in Yuen Long but visited the area surrounding Lion Rock Park.
They all developed symptoms between July 31 and August 22.
There has been a spike in local cases of dengue fever over the past 10 days, with many of the cases concentrated around Cheung Chau and Lion Rock Park. The park was closed for 30 days starting last week, and the Centre for Health Protection (CHP) has urged people not to visit the park during this period.
Several government officials, including the acting secretary for health, Chi Tak-yi, visited a secondary school in Wong Tai Sin, which is near Lion Rock Park, yesterday afternoon.
They observed the mosquito-control measures at PHC Wing Kwong College ahead of the start of the new school year early next month.
Dengue fever is a virus spread through mosquito bites, and can cause fever, headache, vomiting, muscle and joint pains, and rashes. It is potentially fatal.
The government has urged Hongkongers to keep the environment clean and remove stagnant water, which can attract mosquitoes. It also urged people who develop symptoms of dengue fever to contact the CHP to arrange for laboratory tests.