The director of food and environmental hygiene said the department has contacted a number of other government departments to jointly step up anti-mosquito measures. This follows a surge in the index that measures infestations. Eddy Chan Yuk-tak said yesterday he was concerned about the rising Ovitrap Index and feared it may climb higher. He said the department had contacted the Housing Department, Lands Department, and Leisure and Cultural Services Department to strengthen inspections of public areas and prevent accumulations of water, which can become breeding grounds for mosquitoes. 'We will regularly sprinkle insecticide at housing estates and construction sites to eliminate the breeding of mosquitoes,' Mr Chan said. Lam Ping-yan, the health director, urged people to follow good anti-mosquito measures. But he said people did not need to be too worried because the mosquito-borne dengue fever was not epidemic in Hong Kong. The high Ovitrap Index did not mean there was a risk of a dengue fever outbreak, he added. The Ovitrap Index passed the 20 per cent safety level for Diamond Hill, Fanling, Cheung Sha Wan, Happy Valley, Kowloon City North, Tsim Sha Tsui and Wan Chai North earlier this month.