Some types of the avian flu can cause more severe disease in humans than other subtypes and should be watched carefully to prevent spread of disease, a study recently published in the American Society for Microbiology journal mBio said.
The study was done by researchers at the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland.
"Viruses with these avian hemagglutinins have some type of inherent virulence motif to them, in that they induce a marked inflammatory response in mammals including human cells in culture," senior study author Dr. Jeffery K. Taubenberger said. Taubenberger is chief of the Viral Pathogenesis and Evolution Section of NIAID's Laboratory of Infectious Diseases. "From a public health and epidemiology standpoint, it's useful to know that avian viruses of these subtypes (for example, H6, H7 or H10) might lead to more severe infections in humans and is something to look out for," he said.
In 2013 and 2014, approximately 400 cases of avian flu H7N9 infections were reported in China, along with cases of H10N8 and H6N1 subtypes.
The study found that flu viruses expressing the low pathogenicity avian H1, H6, H7, H10 or H15 hemagglutinins (genes that encode the major surface protein for the virus) led to fatalities in mice and caused cell damage in human lung cells.