The WHO is worried that bird flu, which has killed 47 people in Asia, could mutate into an easily spread form that sparks the next influenza pandemic, killing millions.
“Such cases can provide the first signal that the virus is altering its behavior in human populations and thus alert authorities to the need to intervene quickly,” the WHO said in a statement.
The main concern of the WHO was a series of cases of the deadly H5N1 bird flu virus in a family in the northern Vietnam province of Thai Binh and the possible infection of two nurses who cared for one of the patients.
It also said it had received confirmation of an additional 10 cases of human infections from Vietnam’s Health Ministry.
“Full information on new cases, including those that may be closely related in time and place, is critical to ongoing assessment of the pandemic risk posed by the H5N1 virus,” the UN health agency said.
The new cases were detected in early March or through re-examination of older cases.