PHNOM PENH, June 20 (Xinhua) -- Cambodia's Health Minister Mam Bunheng said on Thursday that the country reported over 12,000 cases of dengue fever so far this year, and the dengue fever had claimed 21 children's lives.

The minister revealed the figures during his visit to the patients at a Kantha Bopha Hospital in Phnom Penh.

Bunheng also called on parents to send their ill children to health centers or state hospitals within 48 hours if they suspect that their kids are infected with a dengue virus.

The Kantha Bopha Foundation said in a statement on Wednesday that on Monday alone, 577 children, hospitalized in all five Kantha Bopha Children's Hospitals in Phnom Penh City and Siem Reap province, were tested positive for dengue virus.

Dengue is a viral disease transmitted by Aedes mosquitoes.

The disease causes an acute illness that usually follows symptoms such as headache, fever, exhaustion, severe muscle and joint pain, swollen glands, vomiting and rash.

In Cambodia, the peak of dengue epidemic period is in the rainy season from May to October.

According to a Health Ministry report, there were 24,684 cases of dengue fever with 23 deaths last year compared with 6,372 cases with three deaths in 2017.