ATHENS, Ga., Jun 8, 2009 (UPI via COMTEX) -- U.S. scientists have created the
first model of the avian influenza viruses that takes into account both direct
and indirect transmission among birds.
University of Georgia researchers said their model has the potential to shed new
light on how outbreaks begin in wild bird populations.
"The environmental transmission of avian influenza among birds is quite rare,
but our model shows that it can play an important role in outbreaks," Professor
Pejman Rohani, the study's lead author, said. "There are situations where
ignoring the possibility of environmental transmission would cause you to
significantly underestimate the probability, magnitude and duration of an
outbreak."
Rohani said current models of avian influenza only take into account the direct
transmission of the virus that occurs when infected waterfowl and shorebirds
shed the virus in their feces and those nearby drink contaminated water. But the
new study shows some avian influenza viruses can persist in water for up to 150
days.
So even when no infected birds are present, Rohani said, virus present in the
water can trigger an outbreak. He said models that only take into account direct
transmission would incorrectly conclude there is no risk of an outbreak when no
infected birds are present.
The findings appear in the early online edition of the Proceedings of the
National Academy of Sciences.
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Copyright 2009 by United Press International