The risk to the general population from H5N1 bird flu remains low, a World Health Organization spokesperson said on Tuesday, following the first death of a patient from the virus in the United States.

Nancy Gibson, co-chair of the Legislative-Citizen Commission on Minnesota Resources, called the virus a "time bomb," and said no one knows the true extent of the disease which poses a threat to wildlife and humans.

"While the risk to humans remains low, we are always preparing for any possible scenario that could arise," HSS's Xavier Becerra said.

The first patient hospitalized with avian influenza in the United States has died in Louisiana, the state's department of health announced Monday.

For influenza viruses, imperfection is a strength. They constantly mutate, producing new strains that challenge immune systems primed to fight earlier varieties. That’s what makes flu a life-long threat to humans and the animal species — mainly birds — that are vulnerable to it.