New, possibly tick-borne virus in U.S. ducks

General or non-medical topics with information and discussion related to Lyme disease and other tick-borne diseases.
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RitaA
Posts: 2768
Joined: Thu 1 Jul 2010 8:33

New, possibly tick-borne virus in U.S. ducks

Post by RitaA » Thu 18 Dec 2014 10:12

http://www.news.cornell.edu/stories/201 ... identified
Dec. 15, 2014

Virus causing mass Cape Cod duck die-offs identified

By Merry R. Buckley

Since 1998, hundreds and sometimes thousands of dead eider ducks have been washing up every year on Cape Cod’s beaches in late summer or early fall, but the reasons behind these cyclic die-offs have remained a mystery.

A team of scientists from Cornell, Tufts University, University of Georgia, the U.S. Geological Survey and the U.S. Fish and Wildlife Service (USFWS) have pinned down one of the agents responsible: a pathogen they’re calling Wellfleet Bay virus (WFBV). Their findings shed light on why eider ducks (also called common eiders) die on Cape Cod every year and offer hints about how the virus spreads.

[snip]

With the dead eiders supplied by SEANET and USDA Wildlife Services biologist Randy Mickley, Allison and his colleagues sampled various bird tissues and grew viruses present in the samples in cell culture. They then sequenced the genes of the viruses and compared the sequences with a database of viral genomes.

We isolated the virus repeatedly, over multiple years of outbreaks, and in many birds, which tells us the virus is definitely playing a contributing role and possibly a major role in the die-offs,” Allison said. However, the dead and dying eiders found on Cape Cod have numerous health problems, he said, so it’s likely there are multiple factors to blame. “Lots of the birds are emaciated, and lots have parasitic worms in conjunction with the virus, and it’s possible another factor like stress or migration may also play a role and trigger the deaths,” he said.

Genes that encode proteins on the outside of WFBV hint at a mode of transmission, Allison said. “The surface protein of the virus suggests it might be tick-borne, that somehow the virus is transmitted among birds by ticks,” he said, because all other viruses with these types of proteins on their surfaces have been shown to be spread by ticks or other invertebrates.


RitaA
Posts: 2768
Joined: Thu 1 Jul 2010 8:33

Re: New, possibly tick-borne virus in U.S. ducks

Post by RitaA » Thu 18 Dec 2014 16:51

Here's the abstract for the published scientific article:

http://jvi.asm.org/content/early/2014/1 ... 4.abstract
Accepted manuscript posted online 12 November 2014, doi: 10.1128/JVI.02019-14 JVI.02019-14

Cyclic avian mass mortality in the northeastern United States is associated with a novel orthomyxovirus

Andrew B. Allison a,b*, Jennifer R. Ballard b, Robert B. Tesh c, Justin D. Brown b, Mark G. Ruder b, M. Kevin Keel b, Brandon A. Munk b, Randall M. Mickley d, Samantha E. J. Gibbs e, Amelia P. A. Travassos da Rosac, Julie C. Ellis f, Hon S. Ip g, Valerie I. Shern-Bochsler g, Matthew B. Rogers h, Elodie Ghedin h, Edward C. Holmes i, Colin R. Parrish a and Chris Dwyer j

Author Affiliations

a Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
b Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
c Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555, USA.
d United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, MA/CT/RI Program, Sutton, MA 01590, USA.
e United States Department of the Interior, United States Fish and Wildlife Service, Patuxent Research Refuge, Laurel, MD 20708, USA.
f Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA.
g United States Geological Survey, National Wildlife Health Center, Madison, WI 53711, USA.
h Department of Computational and Systems Biology, Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261, USA.
I Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Biological Sciences and Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia.
j United States Department of the Interior, United States Fish and Wildlife Service, Northeast Region, Division of Migratory Birds, Hadley, MA 01035, USA.

ABSTRACT

Since 1998, cyclic mortality events in common eiders (Somateria mollissima), numbering in the hundreds to thousands of dead birds, have been documented along the coast of Cape Cod, Massachusetts, USA. Although longitudinal disease investigations have uncovered potential contributing factors responsible for these outbreaks, detecting a primary etiological agent has proven enigmatic. Here we identify a novel orthomyxovirus, tentatively named Wellfleet Bay virus (WFBV), as a potential causative agent of these outbreaks. Genomic analysis of WFBV revealed that it is most closely related to members of the Quaranjavirus genus within the family Orthomyxoviridae. Similar to other members of the genus, WFBV contains an alphabaculovirus gp64-like glycoprotein, which was demonstrated to have fusion activity, and also tentatively suggests that ticks (and/or insects) may vector the virus in nature. However, in addition to the six RNA segments encoding the prototypical structural proteins identified in other quaranjaviruses, a previously unknown RNA segment (segment 7) encoding a novel protein designated as VP7 was discovered in WFBV.[/color] Although WFBV shows low to moderate levels of sequence similarity to Quaranfil virus and Johnston Atoll virus, the original members of the Quaranjavirus genus, additional antigenic and genetic analyses demonstrated that it is closely related to the recently identified Cygnet River virus (CyRV) from South Australia, suggesting that WFBV and CyRV may be geographic variants of the same virus. Although the identification of WFBV in part may resolve the enigma of these mass mortality events, the details of the ecology and epidemiology of the virus remain to be determined.

Importance

The emergence or reemergence of viral pathogens resulting in large-scale outbreaks of disease in humans and/or animals is one of the most important challenges facing biomedicine. For example, understanding how orthomyxoviruses such as novel influenza A virus reassortants and/or mutants emerge to cause epidemic or pandemic disease is at the forefront of current global health concerns. Here we describe the emergence of a novel orthomyxovirus, Wellfleet Bay virus (WFBV), which has been associated with cyclic large-scale bird die-offs in the northeastern United States. This initial characterization study provides a foundation for further research into the evolution, epidemiology, and ecology of newly emerging orthomyxoviruses, such as WFBV, and their potential impacts on animal and/or human health.

RitaA
Posts: 2768
Joined: Thu 1 Jul 2010 8:33

Re: New, possibly tick-borne virus in U.S. ducks

Post by RitaA » Thu 18 Dec 2014 17:48

Here are a few related articles (with sometimes conflicting information) about the "new" virus that was apparently first detected at least a couple of years ago. For anyone who may be thinking "So what?" or "Who cares?", be sure to read the Times article at the end of this post.

Even if Wellfleet Bay virus is spread by soft-bodied ticks, could a black-legged tick feeding on an infected bird pick up the virus -- with the potential to then infect other animals and/or humans?

http://www.capecodtimes.com/article/201 ... /203100335
Virus blamed for eider duck deaths

Years of research will be presented today at a conference at Cape Cod Community College on the disease that is only affecting ducks in Wellfleet Bay.

By DOUG FRASER
Posted Mar. 10, 2012 @ 2:00 am

WELLFLEET — A virus is not the kind of thing to have named after your town, but for the past six years scientists have focused on finding out why common eider ducks have been dying by the hundreds, sometimes thousands, in the fall along the shore of Wellfleet Bay.

Veterinarians at Tufts Cummings School of Veterinary Medicine led the investigation, along with the University of Georgia-based Southeast Cooperative Wildlife Disease Study and the National Wildlife Health Center in Wisconsin.
"It's pretty clear, between what the National Wildlife lab found and from the Southeast Cooperative, that there is a new virus found in eiders in Wellfleet that hasn't been detected before," said Sarah Courchesne, project director for the Seabird Ecological Assessment Network at Tufts veterinary school.


Courchesne will be speaking about the research into the eider die-off at the Cape Cod Natural History Conference today at Cape Cod Community College.

Loosely related to the flu virus, it attacks the liver and gallbladders and seems to work very fast. Eider ducks collected from these mass die-offs appear healthy. They are not emaciated from a long illness in which they can't feed.

"They basically die from liver disease," Courchesne said.

National Wildlife scientists discovered the virus while conducting necropsies on dead ducks but couldn't identify it. It was the scientists in Georgia who figured out the virus type and family, Courchesne said. They also named it: Wellfleet Bay Virus.


So far, Wellfleet Bay is the only place in the world known to harbor this virus, although the scientists believe it is related to an equally mysterious Quarjavirus family that is distributed around the world. Ticks spread the diseases in colonies of nesting birds.

Researchers are now trying to discern whether ticks in Wellfleet are infecting the large flocks of eiders that congregate onshore and in the waters in the fall.

During large die-offs, workers collecting duck carcasses have noticed there were also sizeable rafts of eiders floating in the nearshore waters.

Eiders are not endangered or threatened; rather, they are a fairly common seabird with populations estimated to be in the hundreds of thousands. Fifty thousand or more have been spotted floating in huge groups in Nantucket Sound.
So far the disease appears to be confined to the portion of the eider population that summers in Maine and winters on the Cape.

Once they isolated the virus, researchers wanted to know whether they could replicate the disease and show it was the likely culprit. The National Wildlife lab infected eider ducklings with the virus, euthanized them and found the same lesions on the liver.

"The eider, where we have a clear culprit, is one of those rare instances where we have found a thread this strong; it is rare for us and even more exciting," Courchesne said.

Eiders face a different threat when they are in their summer breeding grounds with thousands dying from avian cholera.

Courchesne is concerned about the possibility of a major population decline because of consecutive years in which these twin diseases take large chunks out of the population of adult breeding-age birds.

Global warming and loss of habitat also make birds more vulnerable to disease, Courchesne said.

Habitat loss means birds crowd together in the remaining wild areas, making transmission of disease that much easier. As temperatures rise, ticks can expand their range and remain active longer each year.

Plus less temperature-tolerant diseases can also spread north infecting species which don't have a natural defense against them.

"Climate change could have a huge impact," she said.

http://usfwsnortheast.wordpress.com/201 ... -die-offs/
Searching Boston Harbor Islands for the link to sea duck die-offs

Posted on May 5, 2014 by usfwsnortheastblog

Several hundred, sometimes thousands, of dead common eiders have been found every fall in recent years on the shore of Cape Cod’s Wellfleet Bay. Since 2006, the U.S. Fish and Wildlife Service estimates at least 6,000 of these sea ducks have died at Jeremy Point and other locations along the Cape.

Concerned for the cause of these annual die-offs–and for how other wildlife and perhaps even people might be affected–a group of researchers has come together to study the problem. The investigation has taken us as far north as eastern Canada, and as far south as Rhode Island. It’s led us right back to the Boston Harbor Islands.

“We are worried about the possibility of a population decline due to consecutive years of large losses of adult breeding-age birds,” said Service migratory bird biologist Chris Dwyer. “We’re looking into the source of the die-offs and the role of the recently discovered Wellfleet Bay virus. We–and visitors and residents to the Cape–are wondering what these birds are being exposed to, and is there a connection to the overall health of Cape Cod Bay?”

Last week, researchers from our agency, USGS, University of Pennsylvania, USDA, Biodiversity Research Institute, National Park Service, and Massachusetts Department of Conservation and Recreation and Division of Fisheries and Wildlife continued the investigation with common eider work in the Boston Harbor Islands.

“Eiders represent a group of sea ducks that serve as a barometer of coastal ecosystem health,” he said. “Cape Cod winters large numbers of eiders, and many people are familiar with them and enjoy healthy populations. We need to determine the cause of mortality and the potential implications of this newly described virus to eider populations.”

Here’s what we know:

What’s dying? Eider die-offs in Wellfleet Bay have been occurring since at least 1998, and since 2006, at least 300 to 500 ducks have died each year, mostly in the fall.

What might be the cause? In 2007, a staggering 3,000 dead were found, mostly females, between August and October. From the tissues of five dead eiders that year, researchers from the USGS National Wildlife Health Center isolated an enveloped RNA virus. In 2010, the virus was clarified by the Southeastern Cooperative Wildlife Disease Study and understood to be a newly identified virus, found nowhere else at the time, and it was named the Wellfleet Bay virus. We’re confident the virus has some role in the die-offs.

What is transmitting the virus? The genetic makeup of the virus suggests it comes from an avian soft-bodied tick that we have not found. However, we’re not ruling out other possibilities. Since these are sea ducks, we expect a tick would affect females that spend time on the islands nesting.

Where is it coming from? We started sampling birds in 2011 for this virus. When we looked in Nunavut, Quebec, Nova Scotia, Maine and Rhode Island from 2011-2013, the blood serum of sampled eiders showed that less than 5 percent were positive for the virus. In Massachusetts (the Harbor Islands and Wellfleet Bay), an average of 33 percent of sampled eiders were positive for the virus. In 2012 in particular, a startling 95 percent of sampled eiders in the islands tested positive.

So is it just the birds from the Harbor Islands going to Wellfleet Bay to die? No. The islands birds number less than 400, so they cannot be the only birds making up the die-offs. Some of the birds leave the Islands in the summer to regrow their flight feathers. Through satellite transmitters, we are determining if most of the eiders breeding in Boston Harbor leave to do that, if they stay in Massachusetts or depart for northern areas such as Maine or Nova Scotia (and potentially spread the virus). Either way, when they show up on the other side of the Cape Cod Bay in the fall, we have large die-offs from the birds that stop in Wellfleet Bay.

What did we do this week? Researchers used mist nets to capture eiders off the shore of the islands and used large hand nets (called dip nets) to capture females nesting on the islands. They placed identifying bands around their legs, and took blood, tissue and feather samples for processing. This week, 38 eiders received leg bands, and 10 males and 9 females of that group were fitted with satellite transmitters so that we could get an idea of where these birds go from the islands. Last year, we put out 12 satellite transmitters–half on males and half on females. This year, we recaptured a satellite-marked female from last year and a female that we banded in 2012. We also took soil samples to process for parasites. We will get results from samples in a few weeks, and we’re looking forward to seeing if the two recaptured females will test differently (positive/negative) for the virus this time. MADCR provided vital logistical support, access and collaboration to pull off this work.

What’s next? We plan to return later this year–when the die-offs usually occur–to compare the samples from these ducks to those that come to Wellfleet Bay in the fall.

“The overarching question is, how do we go from Boston Harbor nesting females in the spring with high exposure to this virus to a different area across the Bay in the fall with a die-off of mostly males that are positive for this virus?” Dwyer said. “The die-off events have proven to be far more complex than expected–what is the geographic source of eiders involved in these mortality events, how widespread may the virus occur, what is the potential route of virus transmission among eiders, and is there evidence of previous exposure to the virus and subsequent recovery among healthy eiders?”
http://www.bostonglobe.com/lifestyle/he ... story.html
Searching for the cause of sea ducks’ dire health

Specialists round up common eiders

By David Abel
Globe Staff May 02, 2014

Thousands of their carcasses have been found floating in the cold water off Cape Cod or rotting on beaches. Many more of the birds have been found emaciated, exhausted, and suffering, often near death.

In recent years, a mysterious virus has taken a mounting toll on the region’s common eiders, a normally bulky sea duck considered a barometer for the health of Cape Cod Bay.

A team of federal, state, and local officials fanned out across the Boston Harbor Islands this week to capture eiders, hoping to understand why so many of the migratory birds are dying. Two years ago, 95 percent of eiders sampled in the bramble along the islands’ rocky coasts tested positive for the virus, more than anywhere else along the Atlantic coast.

More recently, the disease, which was identified in 2007 and has since been dubbed the Wellfleet Bay virus, has been found in other species.


[snip]

Dwyer said the losses have been steady but don’t appear to be increasing. Between 250,000 and 300,000 common eiders migrate every year along a corridor from the coast of Labrador in Canada, where they breed, to as far south as Long Island Sound, where they feed on mollusks and other crustaceans. The farthest south they breed is the Boston Harbor Islands.

“If we ignore this, we worry that it could take off quickly,” Dwyer said. “A healthy eider population indicates a clean environment. We worry about the ripple effects if this gets worse.”

[snip]

Scientists believe the virus may be transmitted by ticks or other insects, such as mites or mosquitoes. Other birds that have been found with the virus, including ring-billed gulls and white-winged scoters, have yet to show signs of illness.

But Jennifer Ballard, a wildlife disease diagnostician studying the disease at the University of Georgia in Athens, said it is possible the virus had existed in the birds for years but is only being detected now.

“It’s too early to say whether the virus is being introduced from an outside source,” said Ballard, who will analyze the blood samples and insects that the team sends from the Harbor Islands.

She said the virus is genetically related to a group of viruses found in other migratory sea birds that nest in similarly sized colonies.
The following bird flu history article from Time explains the importance of studying emerging infections in animals. My favourite line/quote is: "When it comes to sniffing out new pathogens, says one epidemiologist, “we’re like a drunk looking for his keys."

http://time.com/3589228/bird-flu-history/
History health

Bird Flu Returns: What Past Outbreaks Can Teach Us

Bryan Walsh @bryanrwalsh
Nov. 17, 2014

Feb. 9, 2004: The Revenge of the Birds

An H5N1 outbreak in Asia kills thousands of chickens — and leads millions more to be slaughtered. Though the number of humans affected is low, the outbreak raises fears about what could happen if the virus mutated.
The virus probably originates in southern China, but no one knows how it has spread so widely. Transport of infected birds to chicken farms is one theory, but it’s also possible that migratory birds such as ducks and geese are spreading it through their droppings. “Did birds in Hong Kong, which nest in Siberia and North Korea, somehow spread the virus elsewhere?” asks Robert Webster, an expert in animal influenzas at St. Jude Children’s Research Hospital in Memphis, Tenn. “That’s a frightening possibility.” If H5N1 does evolve into a flu that humans can spread, a vaccine could be developed but would take months. “Once you know this virus can spread from human to human, region to region,” says Dr. Yi Guan, a SARS and avian-flu expert at the University of Hong Kong, “it’s already too late.”
Sept. 19, 2005: A Wing and a Prayer

The H5N1 virus, previously thought present in domestic animals only, appears in migratory birds, indicating that it has to potential to spread around the world.

For some time, health experts have warned of a worldwide bird-flu pandemic that could kill millions of people and wreck the global economy. “The most serious known health threat facing the world is avian flu,” said WHO director-general Lee Jong-wook earlier this year. And the threat is growing all the time, as nature keeps dropping hints that the links in a chain of events leading to a deadly pandemic continue to be forged. This summer, H5N1 spread west—perhaps in migrating birds—to new territory, including Mongolia, Tibet, Siberia and Kazakhstan. European countries are taking precautions by tightening surveillance of flocks within their borders; in the Netherlands, officials in late August ordered farmers to move the nation’s 90 million poultry indoors to prevent any contact with itinerant fowl. Meanwhile, in Southeast Asia, where at least 58 people have died and 150 million poultry have died or been culled because of avian flu since the end of 2003, the virus is still active; a Jakarta woman died of the disease on Sept. 10. The H5N1 virus has already shown it can be deadly to people who come into direct contact with infected birds or eat uncooked poultry. But bird-to-human transmission is relatively controllable because diseased flocks can be isolated or, usually, eliminated. The sum of all fears is that H5N1 could mutate into a strain with the ability to jump easily from person to person, as ordinary flu does. That could trigger a once-in-a-century catastrophe. How many would die? Nobody knows, or can know.
[snip]

May 18, 2009: How to Prepare for a Pandemic

An outbreak of swine flu (H1N1) highlights the reason why epidemiologists need to spend their time thinking about animals other than human beings. Many dangerous diseases (including Ebola) originate from animals and mutate into viruses that can be spread among humans.

Why should we spend scarce medical resources swabbing the inside of pigs’ nostrils, looking for viruses? Because new pathogens–including H5N1 bird flu, SARS, even HIV–incubated in animal populations before eventually crossing over to human beings. In the ecology of influenza, pigs are particularly key. They can be infected with avian, swine and human flu viruses, making them virological blenders. While it’s still not clear exactly where the H1N1 virus originated or when it first infected humans, if we had half as clear a picture of the flu viruses circulating in pigs and other animals as we do of human flu viruses, we might have seen H1N1 coming. (When it comes to sniffing out new pathogens, says one epidemiologist, “we’re like a drunk looking for his keys.”) Faster genetic sequencing and the Internet give us the technological means to create an early-warning system. But we need to spend more on animal health and get doctors talking to their veterinarian counterparts. “For too long, the animal side of public health has been neglected,” says Dr. William Karesh, vice president of the Wildlife Conservation Society’s global-health program.

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