Scientists at the Center for Infection & Immunity at Columbia University's Mailman School of Public Health, the National Oceanic and Atmospheric Association, New England Aquarium, U.S. Geological Survey National Wildlife Health Center, SeaWorld and EcoHealth Alliance first became concerned in September 2011, when seals with severe pneumonia and skin lesions suddenly appeared along the coastline from southern Maine to northern Massachusetts.
Most of the seals were infants -- 6 months and younger -- and a total of 162 dead or moribund seals were recovered over the next three months, the officials said.
W. Ian Lipkin, director of the Center for Infection and Immunity at the Mailman School of Public Health at Columbia University said pathogen screening was conducted in a subset of the afflicted seals and using sensitive diagnostic tools a new strain of avian H3N8 influenza virus was identified as a culprit.
The study, published in mBio, said based on full genome sequencing and phylogenetic analysis, seal H3N8 descended from an avian strain in North American waterfowl since 2002, which implies recent transmission from wild birds to seals.
Given these findings along with the long history of the spread of avian influenza to humans -- notably H1N1 and H5N1 -- seal H3N8 could pose a threat to public health, Lipkin said.