Monday, August 27, 2018

PRO/AH/EDR> Die-off, seal - USA (02): (ME,NH) influenza & distemper

DIE-OFF, SEAL - USA: (MAINE, NEW HAMPSHIRE) INFLUENZA AND DISTEMPER
*******************************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>

Date: Thu 23 Aug 2018
Source: Sun Journal [edited]
<http://www.sunjournal.com/tests-found-dead-seals-had-avian-flu-and-distemper-viruses/>


Many of the dead seals that washed ashore in northern New England in
the past few weeks tested positive for either avian influenza or
phocine distemper virus, but it is still too soon to say if those
viruses are the primary causes of the unusual die-off, the National
Oceanic and Atmospheric Administration [NOAA] said.

Researchers have been looking for the reasons behind a surge in seal
deaths that began around [12 Aug 2018], when an unusually high number
of dead or sick seals began showing up on beaches in southern Maine
and New Hampshire. More than 400 dead or stranded seals have been
reported along the Maine coast so far this year [2018], including more
than 100 found on beaches south of Portland in the past two weeks
[8-23 Aug 2018].

And rescuers say reports of stranded or dead seals are still flowing
in.

"We have many more samples to process and analyze, so it is still too
soon to determine if either or both of those viruses are the primary
cause of the mortality event," said Jennifer Goebel, a NOAA
spokeswoman.

The preliminary test results showed that 4 of the seals tested
positive for both viruses, NOAA reported.

In 2011, more than 160 seals were found dead on the coast from
northern Massachusetts to Maine between September and December. Tests
conducted on 5 animals showed they suffered from a bacterial pneumonia
caused by a strain of avian influenza -- H3N8 -- that can be
transmitted to seals through contact with seabird guano.

Influenza also was detected in seals in New England during mortality
events 1979, 1982, 1991 and 2006, NOAA said.

Marine animal rehabilitation clinics across the Northeast -- including
Harpswell-based Marine Mammals of Maine -- stopped taking stranded
live seals last week [week of 13 Aug 2018], concerned that healthy
animals in recovery could be exposed to whatever is causing the
die-off.

Since the beginning of the year [2018], more than 400 dead and
stranded seals, the vast majority harbor seals, have been reported in
Maine, more than twice the annual average in the last 7 years, NOAA
said. Rescuers in Maine have reported finding 65 dead seals in July
and 179 dead seals in August. They also found a total of 84 live seals
since the beginning of July.
In New Hampshire and Massachusetts, rescuers reported 30 dead seals in
July and another 58 in August [2018]. During that time, 31 live seals
were rescued, NOAA said. There have not been reports of large numbers
of seals being found sick or dead along the Maine coast north of the
Portland area.

Lynda Doughty, executive director of Marine Mammals of Maine, which
responds to strandings, said she is relieved that researchers are
starting to get some answers about what is happening to the seals. She
was not surprised that preliminary tests showed influenza and phocine
distemper because those viruses are known to be present in the seal
population and seals were showing symptoms consistent with the
viruses.

"I'm glad it's not something new," Doughty said. "We're committed to
keep sampling these animals to learn more about what else might be
going on."

While experts have said viruses are a likely cause of the deaths,
researchers also have said the seal population is at higher risk of
disease because decades of chemical pollution have weakened the
animals' immune systems.

Researches say live seals have showed symptom such as lethargy,
sneezing, coughing, discharge from the nose and eyes, seizures, and
skin abscesses. In dead seals, necropsy findings show signs consistent
with pneumonia, NOAA said.

Some types of flu can be shared between animals and people, but
phocine distemper virus cannot be transmitted to humans. The US
Centers for Disease Control and Prevention, the National Wildlife
Health Center and other organizations are closely monitoring this
mortality event and other animal influenza viruses because influenza
viruses constantly change and it is possible for a virus to change so
it could infect humans, NOAA said.

The agency is warning people not to touch stranded seals and to keep
their dogs away from marine mammals. Doughty said her staff and
volunteers wear protective gear when handling seals or taking samples
because it is not clear what viruses they are dealing with.

The viruses spread between seals through inhalation of respiratory
particles or through direct contact, including between mothers and
their pups. They also can be exposed to the viruses through their
eyes, mouths, stomachs, skin wounds, and the urogenital tract.

While the sudden die-off has shocked volunteers and the public, the
effect on the overall harbor seal population is unclear. Harbor seals
are some of the most common marine mammals in the US, and while
legally protected from hunting, they are not endangered or
threatened.

The harbor seals commonly seen in Maine are part of a population that
lives in coastal waters from the Bay of Fundy in Nova Scotia to New
York and New Jersey. There are approximately 76 000 harbor seals in
the western North Atlantic and the population had not significantly
changed since the last survey in 2012, NOAA reported in its 2017 stock
assessment. The number of gray seals believed to be in US waters is
much lower, around 23 160, according to NOAA's most recent stock
assessment, but scientists believe the population is growing.

[Byline: Gillian Graham]

--
Communicated by:
ProMED-mail from HealthMap Alerts
<promed@promedmail.org>

[Previous mass mortalities of seals in the North Atlantic have been
caused by influenza A viruses. In the past (1979-1983), influenza A
virus was isolated from seals died from pneumonia in New England. The
subtype isolated from the last episode was H3N8.

Another pathogen known to cause seal die-offs is a morbillivirus,
phocine distemper virus (PDV). PDV was first recognized in 1988
following a massive epidemic in harbor and grey seals in north-western
Europe. Since then, the epidemiology of infection in North Atlantic
and Arctic pinnipeds has been investigated. In the western North
Atlantic endemic infection in harp and grey seals predates the
European epidemic, with relatively small, localized mortality events
occurring primarily in harbor seals.

The scenario resembles other wildlife die-off episodes where there is
no single culprit, but perhaps a multifactorial web of causation. When
parasites/pathogens that are part of the normal parasite community of
a host are unusually pathogenic, there might be some underlying
context that is affecting that host-parasite relationship. When the
stress-host-parasite equilibrium is broken, the tolerance and
resistance to parasites is reduced and hosts become increasingly
deteriorated. Both exposure to transmissible diseases and host
susceptibility to infection increase, resulting in a vicious circle
(for a review on the subject see
<http://www.dx.doi.org/10.14409/favecv.v14i1/2.5160>). - Mod.PMB

HealthMap/ProMED-mail maps:
Maine, United States: <http://healthmap.org/promed/p/222>
New Hampshire, United States: <http://healthmap.org/promed/p/231>]

[See Also:
Die-off, seal - USA: (ME) undiagnosed
http://promedmail.org/post/20180814.59656472014
----
Die-off, seal - Europe (03): avian influenza H10N7 susp, new estimates
http://promedmail.org/post/20141217.3039217
Die-off
, seal - Europe (02): Sweden, influenza H10N7
http://promedmail.org/post/20141125.2989464
Die-off
, seal - Europe: (Wadden Sea Nat'l Park) influenza H10N7
http://promedmail.org/post/20141121.2979641
2012
----
Influenza (59): USA (New England), H3N8, seals
http://promedmail.org/post/20120801.1224820
Die-off
, seal, dolphin - USA: New England, update
http://promedmail.org/post/20120209.1037523
2011
----
Die-off, seal - USA (03): New England, influenza
http://promedmail.org/post/20111221.3648
Die-off
, harbor seals - USA (02): New England, influenza
http://promedmail.org/post/20111215.3607
Die-off
, harbor seals - USA: northeast, influenza susp.
http://promedmail.org/post/20111106.3301
Die-off
, seal - USA: New England, RFI
http://promedmail.org/post/20111027.3203]
.................................................sb/pmb/mj/dk
*##########################################################*
************************************************************
ProMED-mail makes every effort to verify the reports that
are posted, but the accuracy and completeness of the
information, and of any statements or opinions based
thereon, are not guaranteed. The reader assumes all risks in
using information posted or archived by ProMED-mail. ISID
and its associated service providers shall not be held
responsible for errors or omissions or held liable for any
damages incurred as a result of use or reliance upon posted
or archived material.
************************************************************
Donate to ProMED-mail. Details available at:
<http://www.isid.org/donate/>
************************************************************
Visit ProMED-mail's web site at <http://www.promedmail.org>.
Send all items for posting to: promed@promedmail.org (NOT to
an individual moderator). If you do not give your full name
name and affiliation, it may not be posted. You may unsub-
scribe at <http://ww4.isid.org/promedmail/subscribe.php>.
For assistance from a human being, send mail to:
<postmaster@promedmail.org>.
############################################################
############################################################

List-Unsubscribe: http://ww4.isid.org/promedmail/subscribe.php

0 comments:

Post a Comment