Avian Flu Makes Jump to Seals, May Pose Threat to Humans

submitted by Susan Steinhauser

AMA - BulletinHEALTHCARE.com

mBio - Emergence of Fatal Avian Influenza in New England Harbor Seals

Many outlets reported on new research, published online July 31 in the journal mBio, which documents a mutated form of avian flu in seals. The sources all discussed the significance of the development, focusing on the risk the transmission of bird flu to mammals poses to humans.

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mBio - Emergence of Fatal Avian Influenza in New England Harbor Seals

Abstract

From September to December 2011, 162 New England harbor seals died in an outbreak of pneumonia. Sequence analysis of postmortem samples revealed the presence of an avian H3N8 influenza A virus, similar to a virus circulating in North American waterfowl since at least 2002 but with mutations that indicate recent adaption to mammalian hosts. These include a D701N mutation in the viral PB2 protein, previously reported in highly pathogenic H5N1 avian influenza viruses infecting people. Lectin staining and agglutination assays indicated the presence of the avian-preferred SAα-2,3 and mammalian SAα-2,6 receptors in seal respiratory tract, and the ability of the virus to agglutinate erythrocytes bearing either the SAα-2,3 or the SAα-2,6 receptor. The emergence of this A/harbor seal/Massachusetts/1/2011 virus may herald the appearance of an H3N8 influenza clade with potential for persistence and cross-species transmission.

http://mbio.asm.org/content/3/4/e00166-12.abstract?sid=d571fb54-8a46-499c-ab34-24ba4cb654c9