The recent appearance of the H5N1 bird flu in pigs does raise viral reassortment concerns. Here's what we know about this highly pathogenic avian influenza virus so far.

A World Health Organization official on Thursday called for stronger surveillance in animals for evidence of infection with H5N1 bird flu in order to curb its spread. The official also urged stronger efforts to reduce the risk of transmission of the virus to new species of animals and to humans.

The developing avian influenza panzootic and the growing possibility of a pandemic bring to the fore the existential questions for humanity of climate change and the destruction of public health, both of which must be stopped in order to control the growing threats.

WHO along with the partnership of World Organization for Animal Health and Food and Agriculture Organization has decided to step up the surveillance of H5N1 virus after a human case was reported in the US earlier this month.

The Centers for Disease Control and Prevention confirmed the first human case of avian influenza A(H5N1) in a child in California last week.

New Zealand has placed strict movement controls on a commercial egg farm in the southern region of Otago after testing confirmed its chickens are infected with bird flu, but said it is not the strain causing concern globally.

A World Health Organization official on Thursday called for stronger surveillance in animals for H5N1 bird flu in order to curb its spread. "What we really need globally, in the U.S. and abroad, is much stronger surveillance in animals,

Dr. Maria Van Kerkhove, WHO director of epidemic and pandemic preparedness, is calling for increased surveillance globally of animal populations that are known to be susceptible to H5N1, including wild birds,