Cambodian Prime Minister Hun Sen said Friday that the country needed to prepare more measures to curb the spread of H5N1 strain of avian influenza, which broke out the worst last year and this year. "We have done a lot to control the spread of the disease through creating bird flu contamination zones, spraying disinfectants in areas where poultry is kept and educating residents, but these are not enough, we need more action plan to control the infection of the disease," the premier said during the closing ceremony of an agricultural conference. "The disease still happens and kills our people in 2014," he said, ordering the Ministries of Agriculture and Health to take more actions and find ways to prevent the disease. Bird flu remains a serious threat to the health of all Cambodians and children seem to be most vulnerable and are at high risk. The country sees the worst outbreaks of bird flu last year, killing up to 14 people and during the first three months of this year, the disease continued to kill additional four people, according to the World Health Organization (WHO). H5N1 influenza is a flu that normally spreads between sick poultry, but it can sometimes spread from poultry to humans, WHO said. The virus was first identified in Cambodia 10 years ago. To date, the country has reported 56 human cases of the virus, killing 37 people, it said.