TAIPEI, Nov. 9 (Xinhua) -- More than 1,000 Taiwan residents have been infected with dengue fever since August, the island's health department said Tuesday.

Kaohsiung City in southern Taiwan was the worst hit with 589 dengue infections, said a health department statement.

Last week the island reported 128 new cases of dengue fever, mostly in the southern cities of Kaohsiung and Tainan.

Warm weather and a high population-density led to the outbreak, as both conditions are conducive to mosquito-breeding. Mosquitos spread the fever.

The number of yellow fever mosquitos and Asian tiger mosquitos, both transmitters of dengue fever, found in Kaohsiung is 20 times more than other cities and counties in Taiwan.

The local government has launched a large-scale program to clean waste disposal sites and deserted buildings.

The health department also set up a headquarters to organize the dengue fever-prevention and control effort in Kaohsiung.