Health officials worldwide are keeping tabs on the spread of H5N1 avian flu among mammals — sparking concern about the possibility of animal to human infection.
Avian flu typically does not infect humans, according to the CDC, but when it does it can cause severe illness or death. In the last 20 years, only 868 humans have contracted it.
Now, the virus has infected more mammals in Peru, causing some experts to note the rise in cases as "a clear mechanism for an H5 pandemic to start," according to Science.
Mammals, including humans, can become infected with the virus via direct contact, according to the CDC. The virus typically jumps from birds to humans via the eyes, nose, mouth or lungs, but scientists suspect that some wild mammals are getting sick after eating infected birds.
Here are six notable events regarding the timeline and spread of avian flu:
- On Feb. 7, veterinary officials in Peru confirmed the strain in sea lions and a dolphin — noting the virus' continued spread throughout Central and South America.
- On Jan. 31 officials from the U.S. Department of Agriculture updated data about the total count of infected wild birds with confirmed cases of avian flu to date. That number now sits at 6,111.
- On Jan. 9, Colorado officials noted that in the state, the avian flu had resulted in the slaughtering of 6 million chickens to stop the spread.
- On Oct. 4, a mink farm in Spain reported an outbreak of avian flu. Fifty thousand mink were killed and carcasses destroyed to control the spread of infection.
- On June 14, a black bear in Canada exhibiting strange behavior died. Its cause of death was determined to be avian flu.
- In May, Michigan and Minnesota had separate reports of wild foxes infected with the disease.