New Seal Flu Could Pose Threat to Humans

TUESDAY, July 31 (HealthDay News) — A new influenza strain found in
New England harbor seals could potentially threaten people as well as
wildlife, new research suggests.

Scientists cautioned that viruses like the newly discovered seal flu
must be monitored in order to predict new strains and prevent a pandemic
flu emerging from animals.

The report was published online July 31 in mBio.

“There is a concern that we have a new mammalian-transmissible virus to
which humans haven’t been exposed yet. It’s a combination we haven’t seen
in disease before,” report editor Dr. Anne Moscona, professor of
pediatrics and of microbiology and immunology at Weill Cornell Medical
College in New York City, said in a journal news release.

Another expert agreed that the flu strain could someday pose a threat
to people.

“Infections that threaten wildlife and human lives remind us how our
health is intermingled on this dynamic planet,” said Dr. Bruce Hirsch,
attending physician in infectious diseases at North Shore University
Hospital in Manhasset, N.Y. He said that while transmission via direct
contact between humans and harbor seals is unlikely, the virus could find
other ways to get to people.

“A dangerous virus infecting mammals increases the risk to us — not by
direct infection — but by evolutionary development of even more riskier
strains,” Hirsch explained. For example, he said, the strain might pass
from seals to birds, expand its presence in the environment and mutate in
ways that make it easily passed to or between humans.

Scientists from several organizations, including Columbia University
and the National Oceanic and Atmospheric Administration, co-wrote the new
report. They said that flu viruses found in mammals, such as the H1N1
“swine flu” that emerged in 2009, can put people’s health at risk. The new
seal flu, they warned, presents a similar threat to humans.

The researchers analyzed the DNA of a virus linked to the death of 162
harbor seals in 2011 off the coasts of Massachusetts, New Hampshire and
Maine. Five autopsies revealed that the seals died from infection with a
type of flu known as H3N8.

The report pointed out that the seal flu is very similar to a flu
strain found in North American birds since 2002. The virus, the
researchers noted, adapted to living in mammals. It also has mutations
that are known to make viruses easier to spread and more dangerous. They
added the seal flu, which is able to target a protein found in the human
respiratory tract, may have the potential to move between species.

The researchers warned that pandemic flu can originate in unexpected
ways, so preparation is essential.

“Flu could emerge from anywhere and our readiness has to be much better
than we previously realized. We need to be very nimble in our ability to
identify and understand the potential risks posed by new viruses emerging
from unexpected sources,” said Moscona. “It’s important to realize that
viruses can emerge through routes that we haven’t considered. We need to
be alert to those risks and ready to act on them.”

Still, viral strains typically must undergo several key mutations to
become the source of a human pandemic, Hirsch said.

“Each time the flu virus infects a cell, it is a roll of the dice,” he
said. “There are eight separate segments of genes inside the virus —
simple viral versions of chromosomes — which recombine at random,
producing unique viruses. Cells can be infected with multiple viruses, so
a dangerous gene from a bird can get mixed in with a gene that makes it
easy to infect humans.”

More information

The U.S. Centers for Disease Control and Prevention provides more
information on the spread of flu viruses from animals to people.

Views: 0

You can skip to the end and leave a response. Pinging is currently not allowed.

Leave a Reply

Powered by WordPress | Designed by: Premium WordPress Themes | Thanks to Themes Gallery, Bromoney and Wordpress Themes