TAIPEI (Taiwan News) — Taipei City’s Department of Health Bureau reported a new case of dengue fever in a 40-year-old man living in Wenshan District on Monday (Sept. 4).

It is the third case of dengue fever reported in Wenshan District, though the newest case did visit Tainan City, a relative hotbed of domestic dengue fever cases. Taipei’s Health Bureau is on guard for community infections that could break out at any moment, per UDN.

Taiwan has more than 4,280 cases of dengue fever, mostly in southern cities such as Tainan and Kaohsiung. The spread of the disease is through infected mosquitoes, Aedes aegypti, which breed easily in outdoor environments where stagnant water is present, such as discarded containers, plant containers, drainage ditches, and even discarded tires.

The new case in Taipei City developed a fever, chills, headache, and muscle aches on Aug. 31. He sought medical treatment the following day (Sept. 1) and his diagnosis was confirmed on Monday (Sept. 4). It’s unclear where he contracted the disease as he recently traveled south to Tainan City during the incubation period, and two of his family members remain asymptomatic.

In response to his case, Wenshan District launched a community cleanup day to remove any community breeding sources for vector mosquitoes. There was also prevention and control work, such as spraying and disinfecting outdoor and indoor areas.

Taipei City Department of Health said that as of Monday (Sept. 4), there have been 36 confirmed cases of dengue fever in Taipei City, including 27 imported cases and nine local cases. The dengue fever cases are distributed across four different administrative districts, including three cases each in Wenshan District, three cases in Beitou District, two cases in Zhongshan District, and one case in Datong District.

Taiwan is on alert for a domestic dengue fever epidemic, urging the public to "patrol, pour, clean, and brush" their community. Citizens are instructed to look carefully for any accumulation of stagnant water, which can provide vector mosquitoes with a place to lay eggs.

Dengue fever transmission in Taiwan typically coincides with the rainy season, which peaks between May and August. Drier weather typically eliminates potential breeding locations for the vector mosquito, which spreads the disease.

Dengue fever is rarely fatal as Taiwan has only recorded two fatalities so far this year. Still, Taiwan health officials worry the arrival of Typhoon Haikui could extend the peak season for the spread of the disease, which has already topped that of previous years, but is still far off from 2015 when 43,000 cases were reported.