Scientists find mutations that may let bird flu spread among humans

National Institute of Allergy and Infectious Diseases, National Institutes of Health

Scientists have identified mutations that could allow a lethal strain of bird flu to become more contagious among humans, according to a study in PLOS Pathogens.

Why it matters: The H7N9 strain of bird flu has killed at least a third of the estimated 1500 people it has infected in China since 2013 - and there has been a surge in cases this year. The strain currently doesn't pass easily between people and most cases have occurred after people come in contact with infected poultry. But public health officials are concerned about the potential for H7N9 to mutate into a contagious virus, like other flu viruses have in the past.