Concern is rising among health experts about the possibility of an H5N1 avian flu pandemic, as the strain has now been found in mammals. A Spanish mink farm was infected with the virus in October, signaling to experts the strain's capability to evolve and spread to other mammals, including humans, at possible pandemic levels.
Tom Peacock, PhD, a virologist at Imperial College London, told Science, "This is a clear mechanism for an H5 pandemic to start."
Although none of the workers at the farm contracted H5N1 themselves, the virus' fatality rate after infection is very high in human cases.
Avian flu typically does not infect humans, according to the CDC. As of now, in the last 20 years, only 868 humans have contracted the deadly strain worldwide, but it is something infectious disease experts are keeping close tabs on because of the ongoing rampant infections seen in birds this year. Specifically, the H5N1 strain has "been responsible for most human illness from bird flu viruses worldwide to date, including the most serious illnesses and illness with the highest mortality," the CDC says.
Human cases generally are caused by direct contact with contaminants, though the CDC says it's critical for public health officials to monitor, as the strain can continue to evolve.
"Because of the possibility that bird flu viruses could change and gain the ability to spread easily between people, monitoring for human infection and person-to-person spread is extremely important for public health," the CDC's guidelines read.