The recent hot and rainy weather is ideal for mosquito eggs' hatching, the Food & Environmental Hygiene Department says, adding the index that measures mosquito numbers is quickly rising.

The Ovitrap Index recorded in nine areas exceeded 10% in May, and in Wong Tai Sin Central, it hit 28.8%.

The department activated the district inter-departmental anti-mosquito response mechanism there, as the reading fell into the alert zone of 20-40%.

The other eight areas with comparatively high index readings are Kennedy Town (19.2%), Yau Ma Tei (17.3%), Fanling (17.3%), Cheung Sha Wan (16.3%), Sham Shui Po East (13%), Diamond Hill (12.8%), Tuen Mun South (11.1%) and Kwai Chung (10%).

Relevant government departments will step up inspections and efforts to enhance environmental hygiene conditions as well as eliminate existing and potential mosquito-breeding grounds.

The index readings for other districts are also expected to climb.

Special anti-mosquito measures will be adopted in the major outlying islands frequently visited by holiday hikers. These include Cheung Chau, Mui Wo, Peng Chau and Lamma Island.

How to prevent mosquito breeding

To avoid potential mosquito breeding, people should:

* remove stagnant water;

* properly dispose of refuse, particularly empty lunch boxes and soft drink cans that may retain water;

* cover tightly all water containers, wells and water storage tanks;

* fill up all defective ground surfaces with sand, mud or cement;

* clear refuse and fallen leaves from drains and surface channels to prevent blockage;

* scrub and limewash drains and surface sewers with an alkaline detergent compound at least once a week;

* wrap disused tyres properly or puncture them to prevent water being trapped;

* change or remove water in flower vases or saucers underneath potted plants at least once a week; and

* ensure no stagnant water is accumulating in traps under air-conditioning units.