Catastrophic disease events in marine mammals mostly caused by viruses

Date: June 18, 2020

Source: Virginia Tech

As the COVID-19 pandemic sweeps across the globe, people are beginning to understand, at a very personal level, the ways in which infectious diseases can devastate life. But disease outbreaks are not confined to just humans or to life on land.

"We are perhaps more alert than ever to the catastrophic impacts of infectious disease in both humans and animals. Our task now is to begin to understand what drives these events, particularly in species like marine mammals, where our knowledge is even more limited," said Claire Sanderson, a research associate in the Department of Fish and Wildlife Conservation within the College of Natural Resources and Environment and the research coordinator of the Center for African Resources: Animals, Communities, and Land Use (CARACAL).

In 2000, over 10,000 endangered Caspian seals died in less than a four-month span. Researchers later discovered that the culprit behind this devastating mass mortality event was canine distemper virus.

Infectious disease-induced mass mortality events are known to afflict a variety of species, including invertebrates, birds, fish, and both land and aquatic mammals. However, these events in aquatic mammals are understudied compared to their land-dwelling counterparts.

Continued

Emerging significance of gammaherpesvirus and morbillivirus infections in cats

Date:  January 22, 2019

Source:  SAGE

Emerging infectious diseases comprise a substantial fraction of important human infections, with potentially devastating global health and economic impacts. A 2008 paper in Nature described the emergence of no fewer than 335 infectious diseases in the global human population between 1940 and 2004. In the veterinary field, just as in the medical field, advanced molecular techniques and sophisticated computer-based algorithms for genetic sequence assembly and analysis have revolutionised infectious disease research. They have also raised important questions, as the potential pathogenic role of novel viruses can be difficult to determine.

What is well understood is that novel viruses may contribute to diseases that are major causes of feline morbidity and mortality, including cancer and chronic kidney disease (CKD). A state-of-the-art review article published in the Journal of Feline Medicine and Surgery this month focuses on two novel viruses that have the potential to negatively impact feline health and welfare globally -- gammaherpesvirus and morbillivirus. Writing for an international audience of veterinary practitioners and feline researchers, an expert group of feline virologists, clinicians and pathologists from Australia, New Zealand and the USA, led by Dr Julia Beatty, of the University of Sydney, discusses aspects related to virus discovery, epidemiology, pathogenesis, diagnosis, prevention and zoonotic potential.

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Disease poses risk to chimpanzee conservation, study finds

Date:

March 10, 2015

Source:

Emory Health Sciences

Summary:

Infectious disease spillover, including from humans to animals, poses risk to the chimpanzees of Gombe Stream National Park, where Jane Goodall began her pioneering behavioral research in 1960.

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Slime-producing molecules help spread disease from cats to sea otters

8th October 2014 

41 minutes ago by Pat Bailey

(Phys.org) —The spread of diseases from land animals to sea otters and other marine mammals is aided and abetted by gelatinous, sticky polymers produced by seaweed, reports a research team headed by a UC Davis veterinary infectious-disease expert.

These large, complex molecules form slimy biofilms and bind water-borne organic matter into larger particles, in which disease-causing microorganisms can become embedded and introduced to the marine food chain, the researchers discovered.

Using the parasite Toxoplasma gondii as a model, they showed how these sticky polymers increase the chance that disease-causing organisms would be picked up by marine snails, which graze on kelp and are among the common foods of some endangered sea otters.

Findings from the new study will be published Oct. 8 in the journal Proceedings of the Royal Society B.

Read more at: 

Losing Stream in Our Battle to Predict and Prevent Invasive Species

ScienceDaily (Aug. 22, 2012) — Invasive species -- plants, animals, and microbes introduced to regions beyond their native range -- carry a global price tag of $1.4 trillion dollars. They are responsible for the loss of natural resources and biodiversity, damages to infrastructure, and an uptick in infectious diseases.

Not all non-native species pose a threat. Scientists around the world have spent the last several decades teasing apart the conditions that set the stage for debilitating invaders, like giant hogweed, zebra mussels, or gray squirrels. A number of hypotheses have emerged to help predict how natural areas will respond to introduced plants, animals, and microbes.

An analysis of 371 invasion studies using six dominant invasion hypotheses has revealed their predictive power is weakening. The paper's authors -- Jonathan Jeschke, Lorena Gómez Aparicio, Sylvia Haider, Tina Heger, Christopher Lortie, Petr Pyšek, and David Strayer -- found empirical support for all six hypotheses declining, with recent studies showing the lowest levels of support. Hypotheses that were too broad or omitted ecosystem interactions fared among the worst, plants proved easier to predict than animals, and, contrary to popular belief, diverse ecosystems were not inherently resistant against invaders. The study was published in the open-access journal NeoBiota.

Continued: http://www.sciencedaily.com/releases/2012/08/120822101117.htm

Environmental Concerns Increasing Infectious Disease in Amphibians, Other Animals

ScienceDaily (July 18, 2012) — Climate change, habitat destruction, pollution and invasive species are all involved in the global crisis of amphibian declines and extinctions, researchers suggest in a new analysis, but increasingly these forces are causing actual mortality in the form of infectious disease.

Amphibians are now, and always have been hosts for a wide range of infectious organisms, including viruses, bacteria and fungi, scientists said in a review published inPhilosophical Transactions of the Royal Society B.

But in recent decades, disease seems to have taken a more prominent role in causing mortality. Because of multiple stresses, many induced by humans, amphibians now succumb to diseases they may historically have been better able to resist or tolerate.

"There's more and more evidence of the role of disease in the biodiversity crisis, in both amphibians and other types of animals," said Andrew Blaustein, a distinguished professor of zoology at Oregon State University and author of the recent analysis.

Continued:  http://www.sciencedaily.com/releases/2012/07/120718143607.htm

Are Frogs Rapidly Facing Extinction?

While scientists argue over what factors are to blame, more than 40 percent of amphibious species are at risk for "imminent extinction."

By JASON KOEBLER

If you happen to see a frog hopping around in your back yard, take a good look— it might not be around for much longer. Ecologists are increasingly warning that due to habitat destruction, widespread infectious disease and climate change, amphibians are facing "extinction in real time."

As many as 40 percent of amphibious species, which include frogs, salamanders and newts, could be facing "imminent extinction," according to David Wake, a researcher at the University of California Berkeley.

"It's happening around the world … we're seeing it on our watch," he says. "People talk more about birds or mammals because they are charismatic, they're in the public eye. I'm concerned about rhinos and tigers, too, but in the meantime, we're losing the things that are in our backyard."

Scientists first began noticing the decline in the late 1980s, but despite increased awareness, amphibious populations haven't grown.

"If anything, the problem has gotten worse," Wake says. "The attention we've given to it has led to some surprising discoveries," such as Chytridiomycosis, an infectious disease caused by a fungus that lives around the world and has a near 100 percent mortality rate in amphibious animals. So far, biologists haven't been able to stop the disease.

Read on:  http://www.usnews.com/news/articles/2012/03/02/are-frogs-rapidly-facing-extinction