There are now over 10,600 residents reported to have been afflicted with dengue fever, with 13 confirmed dead as of Tuesday, according to Taiwan's Center for Disease Control (CDC).
CDC spokesman Chou Jih-haw said that this year Taiwan has experienced its most severe outbreak of the disease in the past decade, exceeding previous years when annual cases would not exceed 2,000.
Dengue fever is an infectious tropical disease spread by the Aedes mosquitoes with symptoms that include fever, headache, muscle and joint pain, and skin rashes. In certain cases, the disease can develop into hemorrhagic dengue fever which can sometimes be fatal.
All 13 of the confirmed dead were between 64 and 79 years of age and had histories of high blood pressure, heart disease, or rheumatoid or metabolic arthritis, according to the Kaohsiung health bureau.
Most of this year's cases, about 10,100 of them or 97 percent of the total, were in Kaohsiung City in the southern part of the island.
The warm weather since April and the more-than-usual increase in this year's rain fall--both of which are conducive to the breeding of the mosquitoes that carry the dengue virus--may have been responsible for the outbreak in the city, said Chou.
A deadly gas blast in the city that killed dozens in late July could also have played a part in the spread of the disease, Chou added.
The situation in Kaohsiung has prompted Taiwan's Control Yuan to launch an investigation on whether or not the city's health and environment authorities have been remiss in the discharge of their duties.
According to Focus Taiwan, government watchdog members Jane Chiang and Teresa Yin will be looking into the dengue fever cases this year.
The Control Yuan said in its press release: "We would like to see if the relevant authorities and responsible public servants have not done their duties properly."