Monday, January 11, 2010

Influenza's call of the wild

Published On Mon Jan 11 2010

What animals can help spread flu viruses? Two wildlife disease experts examined which species might act as reservoirs for influenza viruses and be "mixing vessels" in which new strains are generated. They analyzed complex carbohydrates found on the surface membranes of cells, which can act as "receptors" for influenza viruses.

Mark Schrenzel and Bruce Rideout already knew H5N1, the avian strain of influenza, makes use of receptors containing an alpha 2,3 sialic-acid linkage, whereas H1N1 strains employ the alpha 2,6 sialic-acid bond. They also knew any species (domesticated swine being one) that carries receptors of both types could act as a mixing vessel. They set out to find which animals have what, focusing on species likely to meet waterfowl like geese and ducks, known to be vulnerable to H5N1. The researchers analyzed the receptors of 60 species.

AT RISK OF H5N1 AND H1N1

The North American striped skunk, left, and the Persian leopard were found to carry receptors for both H5N1 and H1N1 and could serve as mixing vessels.

POSSIBLE H5N1 THREAT

The opossum has the avian flu receptor, as do the arctic fox, Chinese wolf and corsac fox.

UNLIKELY TO BE INFECTED

The bald eagle, along with the European otter, polar bear and raccoon, lacks the receptors to make it vulnerable to H5N1.

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