Deadly Bird Flu In Seals Could Threaten Humans

Researchers have found a deadly strain of the avian influenza virus that has been sweeping through harbor seals may be able to spread to humans.

That's according to a study recently published in the peer-reviewed journal Nature Communications.

The study, led by investigators from St. Jude Children's Research Hospital, details how an avian H3N8 virus strain that had killed more than 160 seals along the New England coast back in 2011 boasted specific characteristics that allowed it to be easily spread through respiratory droplets and made it a potential threat for human infection.

"This study highlights a gain-of-function experiment that occurred in nature and shows us there are avian flu viruses out there beyond H5N1 and H7N9 that could pose a threat to humans," co-author Stacey Schultz-Cherry, and infectious disease experts, said in a recent statement.

According to the study, lab samples of the 2011 strain boasted mutations in key protein production that previous laboratory research had shown allows the highly pathogenic avian H5N1 virus to spread though the air. Tests with these samples showed that the virus could efficiently grow in human lung cells, despite the fact that - luckily - no cases of H3N8 avian influenza were ever tied to the seal outbreak.

Lead author Erik Karlsson asserted that these findings should reinforce a need for officials and the scientific community to closely keep watch of an increasingly number of bird flu strains that are circulating among various wild and domesticated animals.

According to the study, the researchers also took blood samples from 102 individuals who had been vaccinated for seasonal flu strains between 2009 and 2011. Interestingly, they were found to not have any antibodies that could protect them against the harbor seals' virus.

"The transmissibility of the seal H3N8 virus coupled with the apparent lack of immunity makes this strain a concern," the investigators wrote, adding that they will be staying vigilant of any new H3N8 cases.