The incidence of dengue fever had spiked, increasing by about 10 per cent during the first three months of this year, health officials said yesterday.

So far this year, there had been 1,499 dengue-fever cases, compared to 1,365 cases at the same time last year, Dr Ngan Chantha, director of the Health Ministry’s national dengue control program, said.

The disease was striking the most vulnerable, with the greatest number of cases in teenagers and children under 15, Chantha said.

But even though the number of cases increased, the number of deaths has held steady, with eight victims dying so far.

The increase comes just before the rainy season - trad-itionally the time of year when the most cases of the disease are seen.

Chantha blamed the increase on climate change and human migration,  referring to infected individuals who introduce the virus to areas not affected by the disease when they travel.

But Sonny Krishnan, communications officer with the World Health Organisation in Cambodia, said there was no proof climate change was causing a spike in the disease.

“There are several factors involved. Most of all, people don’t realise the Aedes mosquito is an indoor-breeding mosquito and don’t check the clean standing water in unsuspected spots in their houses,” he said.

The mosquito-borne disease was spread by the Aedes mosquito, which bred in urban areas - unlike the mal-arial mosquito, which was found in rural and forested areas, Krishnan said.

“Unlike malaria, which is spread by a night-time biting mosquito, the Aedes mosquito bites during the day.”

Krishnan said ignorance and incorrect knowledge of the disease was the most likely cause for the increase.

Cambodians should take precautions such as looking for mosquito larvae in clean, standing water in their homes, he said.

“People here store a lot of clean water indoors in large earthern jars, which are mosquito breeding sites.

“They can put guppy fish in these jars, which has been shown to be effective in destroying the Aedes larvae.”