Three new imported dengue fever cases were found in two weeks in Tainan, health authorities in the southern city announced Monday.

A 23-year-old migrant woman from Indonesia, who was intercepted and referred for medical attention upon her arrival at the airport on April 25, was later confirmed as the 15th victim of imported dengue fever, the Tainan City Government’s Dengue Fever Prevention and Control Center reported.

To play it safe, the authorities sent officers to the South District where the woman lived. They disinfected the area and introduced mosquito control measures in the neighborhood.

The 16th patient was a 34-year-old Taiwanese businessman from Jiali district who was a frequent traveler to Cambodia. It was reported that he had had a fever as early as April 23 and sought medical attention on April 30 when he arrived in Tainan. He was diagnosed with dengue by May 2.

The 17th case involved a 32-year-old Taiwanese man in Yanshui district who had visited Thailand in April. By May 5, he sustained muscle pain and had a fever the following night, leading him to get medical attention at a nearby a hospital, where he tested positive in the NS1 antigen test for dengue.

Authorities appealed to the public to seek medical assistance at once if they have developed a fever, particularly if they had traveled abroad. Measures on preventing mosquito bites and mosquito breeding such as preventing accumulation of stagnant water should be carried out prior to the rainy season.