The virus can be passed on to humans who handle or eat infected birds. It has killed 331 of the 565 reported humans who contracted the virus since it first emerged in 2003.

While the virus was thought eradicated from the 63 countries where infections occurred at its peak in 2006, the Food and Agriculture Organization (FAO) cautioned that it has been expanding in both poultry and wild birds over the past few years.

Millions of birds were slaughtered across Asia and parts of Europe to combat the virus’ spread.

FAO chief veterinary officer Juan Lubroth cautions that a variant strain of H5N1 found in China and Vietnam appears to be able to sidestep the defenses of existing vaccines.

A six-year-old Cambodian girl just became the eighth person to die from avian influenza so far this year, according to the World Health Organization.

Photo: United Nations - FAO