This 2003 photo provided by the Centers for Disease Control and Prevention shows a female Aedes albopictus mosquito acquiring a blood meal from a human host. (JAMES GATHANY/CENTERS FOR DISEASE CONTROL AND PREVENTION VIA AP)

HONG KONG – The number of Aedes albopictus mosquitos, which can transmit dengue fever and Zika virus, decreased significantly in Hong Kong, according to a monthly index.

The monthly gravidtrap index for Aedes albopictus fell from 21.1 percent in June to 9.7 percent in July, dropping from Level 3 to Level 2, which indicated that the distribution of Aedes albopictus in the areas surveyed was fairly extensive but dropped to a relatively low level, the Food and Environmental Hygiene Department (FEHD) announced on Tuesday.

Among the 64 survey areas in the city – mostly located in the vicinity of public and private residential areas, schools, recreational and sports facilities and public places, the area gravidtrap index (AGI) in six areas exceeded the alert level of 20 percent last month.

The government is very concerned about mosquito infestation.

Food and Environmental Hygiene Department, HKSAR

“The FEHD has collaborated with relevant government departments by taking immediate action to strengthen mosquito prevention and control work in the areas concerned,” the FEHD said in a news release.

The monthly density index for Aedes albopictus was 1.3 in July, showing that an average of 1.3 Aedes albopictus adults were found in the Aedes-positive gravidtraps, indicating that the number of adult Aedes albopictus was not abundant in the surveyed areas. 

Saying that the government is very concerned about mosquito infestation, the FEHD appealed to the public to work together to carry out mosquito prevention and control measures early.

Pointing out that dengue fever is commonly found in tropical and subtropical regions of the world, and has become endemic in many countries in Southeast Asia, the FEHD cautioned that dengue activity in neighboring areas has remained high.

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The FEHD urged residents to inspect their homes and surroundings to remove potential breeding grounds, change the water in vases and scrub their inner surfaces, remove water in saucers under potted plants at least once a week, properly dispose of containers such as soft drink cans and lunch boxes, and drill large holes in unused tires. 

The FEHD also advised members of the public and estate management bodies to keep drains free of blockage and level all defective ground surfaces to prevent the accumulation of water.