Recent flooding has extended the dengue fever season this year, the National Dengue Control Program said on Tuesday.

Officials added that more than 12,000 people, primarily children, had been hospitalised so far this year with the mosquito-borne infection.

Dr Ngan Chantha, head of the NDCP, said “12,392 people had been hospitalised with dengue fever in the first nine months of this year, compared to 9,582 in total last year”.

He also said that 54 children had died from the disease in the first nine months of this year, compared to 28 last year.

Outbreaks of dengue fever coincide with the rainy season, when  there a many pools of water  in which the mosquito that transmits the virus can lay its eggs.

“Although the country is close to the end of dengue season, the flooding is in danger of causing a dengue fever outbreak,” Ngan Chantha said.

“Mosquitos can breed in any places where there is water, so breeding places are widespread now.”

He urged parents to ensure that their children receive immediate treatment if they have symptoms of dengue, which include high fever, aching joints, rashes, and aching behind the eyes.

If not treated properly, or if treatment is delayed, the disease can develop into haemorrhagic fever, which can be fatal.

Meanwhile, a spokesperson for the World Health Organisation in Manila said that the disease was under reported in the region.

“There is always under-reporting yearly because not all clinics have the capacity for diagnosis,” Marilu Lingad said by email.

According to the WHO, dengue fever is the fastest emerging viral infection spread by mosquitoes globally, the Asia-Pacific region has been the hardest hit, and Cambodia is among the countries in the region with the highest incidence of dengue.

The number of annual reported cases of dengue in the region doubled from about 100,000 in 2000 to 200,000 in 2007, and rose to about one-quarter of a million cases in 2009, according to the WHO.

The virus has four serotypes and it is believed that successive infections of each serotype can lead to more serious symptoms. The prevailing serotype this year is DEN2, Ngan Chantha said, adding that last year the prevailing serotype was DEN1. In 2007, more than 10,000 Cambodians were hospitalised with dengue within one week.