The outbreak of dengue fever is raising concerns among health experts in Chiang Mai, given nearly 6,000 people have been afflicted by the disease in the province since the beginning of this year.

The Chiang Mai provincial health unit said a total of 5,977 cases of dengue fever have been reported in the area, with five fatalities so far. The number of dengue patients is on the rise at an alarming rate, from 140 in January to 3,059 in June.

In June of last year, only 170 people were infected by the virus.

A total of 11 districts in Chiang Mai are on high alert for the mosquito-borne disease which include Mueang, Mae Rim, Fang and San Pa Tong districts.

There have been over 50,000 cases of dengue fever reported nationwide. The Public Health Ministry has urged all related agencies to step up prevention measures, including cleaning all water containers and sewer drains, using mosquito-killer sprays, and eliminating all mosquito breeding grounds.