Hong Kong’s Lion Rock Park will be closed for 30 days starting from Friday evening, as authorities work to wipe out mosquito breeding sites after four more Hongkongers were confirmed to have the dengue virus. The three men and one woman — aged between 40 and 71 — had visited the park in Wong Tai Sin for exercise or barbecues. The new cases bring the total number of people who acquired the mosquito-borne virus locally to 11, more than the seven cases recorded between 2015 and last year. Of the seven confirmed to have the virus between Tuesday and Thursday, five had also visited the park. The decision to temporarily close the park was announced after a meeting of the Pest Control Steering Committee, made up of government representatives from different departments, on Friday afternoon. “[The shutdown] will facilitate government departments to conduct a thorough site cleansing and mosquito control work,” said Assistant Director of Leisure and Cultural Services Simon Liu Wai-shing. He said notices at the site would inform the public about the shutdown and staff would be stationed at the park to do the same. The Undersecretary for Food and Health Dr Chui Tak-yi said the decision to close the park – a popular spot for hikers, especially on the weekend – was aimed at reducing the chances of further infections. “We hope the public will be more vigilant with this measure...and reduce their chances of coming into contact with mosquitoes carrying the dengue virus,” Chui said. Lion Rock Park, covering an area of 5.07 hectares, has more than 300 trees and other shrubs. Some of its facilities include barbecue areas, an elderly fitness corner and a community garden. The dengue virus is spread by the Aedes albopictus mosquito, common in Hong Kong. Those infected are likely to display symptoms such as high fever, severe headache and muscle pain. While fatalities are rare, the risks are higher for elderly patients. Since the first four cases were confirmed, medical experts have warned of an outbreak, as mosquito breeding tends to spike in the summer months when it is hot and wet. They said a rise in cases would further strain the city’s public healthcare system. Health officials take action to prevent outbreak of dengue fever in city Lee Ming-wai, who is in charge of pest control operations at the Food and Environmental Hygiene Department (FEHD), said authorities decided on a 30-day closure period as adult mosquitoes have a lifespan of about one month. If there were no new dengue infections linked to Lion Rock Park in the next month, it would suggest that the mosquito situation there was under control. But if there continued to be infections that could be traced to the park, the period of closure might be extended, he said. Dr Wong Ka-hing, who heads the health department’s Centre for Health Protection, also confirmed that genetic sequences of the virus carried by six of the dengue fever victims diagnosed between Tuesday and Thursday were the same. “What this reflects is that the source of infection is very likely to be the same one,” Wong said. The mosquito spreads the virus by biting an infected person and then passing it to the next person it bites. Earlier on Friday, FEHD workers fogged the park with insecticide while staff gave blood to check whether they had been infected with the virus. Doctors also urged people to seek medical help if they were bitten by mosquitoes and had feverish symptoms.