Cheung Chau man confirmed to have dengue fever is 24th person in Hong Kong with mosquito-borne virus this year
Centre for Health Protection also records imported case of similar viral disease chikungunya fever
A 66-year-old man from Cheung Chau was confirmed to have dengue fever on Friday, bringing the total number of people in Hong Kong who have contracted the mosquito-borne virus locally to 24 this year, health authorities said.
Seven out of all those infected either live on or had visited Cheung Chau island, while the remaining 17 had gone to the popular Lion Rock Park or Wong Tai Sin, the district where the park is located, since August 14.
The man in the newest case had no travel records during the incubation period, according to the Centre for Health Protection. He lives in Lung Tsai Tsuen on Cheung Chau, and his condition was stable as of Friday.
Separately, the centre recorded an imported case of chikungunya fever – a mosquito-borne viral disease – between August 18 and 24. Its symptoms include fever and joint pain.
The surge in cases over an 11-day period has worried medical experts, with some doctors concerned there could be another spike when the new school year starts in the first week of September.
During a visit to a school in Wong Tai Sin on Friday, health authorities said they expected more cases to emerge from Cheung Chau.
“This would not be surprising because we know there is an incubation period,” acting Secretary for Food and Health Dr Chui Tak-yi said.
When asked if officials would advise tourists and residents not to go to the island, Chui assured that the government had already stepped up mosquito control in the area.
“We will continue to deploy anti-mosquito measures in the two areas for more than a month,” Chui said of Cheung Chau and Wong Tai Sin. “As for the residents of Cheung Chau, we suggest they continue taking preventive measures to protect themselves.”
Chui also said on Friday officials would monitor schools within a 500m radius of where the dengue fever patients live before the start of the school year to ensure mosquito control measures had been properly implemented.
He added that it was important for schools to designate a staff member to oversee the prevention efforts carried out by frontline workers.
Meanwhile, Hong Kong Medical Association president Dr Ho Chung-ping warned that a second wave of dengue cases was possible by early next month if the current outbreak was not halted.
The association urged schools to use the time ahead of the new academic year to ensure that all stagnant water was removed.
“As classes will resume in early September and there will be a high concentration of these children staying together, we have to be on guard,” he added.
Ho cautioned residents in Cheung Chau and Wong Tai Sin to be “stringent about their mosquito control”, noting the insects could still go to nearby residential areas.
A Food and Environmental Hygiene Department spokesman said this summer’s “hot and rainy weather” had been “favourable for massive mosquito breeding, which may aggravate the risk of spreading mosquito-borne diseases through mosquito bites”.
Ho added that, while Hong Kong is subtropical, it was “getting to be more tropical”. He noted that temperatures were approaching those of tropical countries such as Malaysia, Singapore and the Philippines.
In Hong Kong, dengue fever is transmitted to humans by Aedes albopictus, a type of mosquito commonly found locally.
Most dengue fever cases in the city in previous years were imported – patients were bitten elsewhere and displayed signs of the illness upon returning.
There were 20,108 cases of dengue between January and March 10 this year in the Philippines. Malaysia tallied more than 47,000 as of August 23 this year, and Singapore had 1,731 cases.
China has reported 451 dengue cases this year.
In other tropical Asian countries, dengue has been spread by another mosquito, the Aedes aegypti.