A two-year-old Cambodian boy has died from bird flu, the World Health Organization (WHO) said, in the country's first fatality from the virus this year.

The child, from northwestern Banteay Meanchey province, fell ill on January 3 and was taken to hospital where he tested positive for H5N1 avian influenza. He died on January 18, the WHO said on Thursday.

"The boy is the 19th person in Cambodia to become infected with the H5N1 virus; to date, 17 of these cases have died from complications of the disease," the UN health agency said on its website.

Last week, when the child was still in critical condition in hospital, the Cambodian health ministry and the WHO said in a joint statement that the patient had been exposed to sick poultry prior to becoming ill.

All of Cambodia's eight bird flu cases last year were fatal -- the last of them in August. Seven of the victims were children.

The H5N1 strain of avian influenza has killed 341 people worldwide since 2003, according to WHO statistics.