Amphibians and bats

I mainly focus on human diseases in this class but over the last week I did branch out a little. Some recently emerging diseases I did not discuss were the chytrid fungus affecting frogs and the fungus that causes white-nose syndrome in bats. Both of these are causing serious conservation problems.

The March 2013 issue of Emerging Infectious Diseases, a publication of the CDC, has a nice review:

Parallels in Amphibian and Bat Declines from Pathogenic Fungi


Abstract
Pathogenic fungi have substantial effects on global biodiversity, and 2 emerging pathogenic species—the chytridiomycete Batrachochytrium dendrobatidis, which causes chytridiomycosis in amphibians, and the ascomycete Geomyces destructans, which causes white-nose syndrome in hibernating bats—are implicated in the widespread decline of their vertebrate hosts. We synthesized current knowledge for chytridiomycosis and white-nose syndrome regarding disease emergence, environmental reservoirs, life history characteristics of the host, and host–pathogen interactions. We found striking similarities between these aspects of chytridiomycosis and white-nose syndrome, and the research that we review and propose should help guide management of future emerging fungal diseases.

Xenophobia and disease

An interesting post at the Scientific American blog about the relationship between xenophobia and disease.
Do Wild Bats Hold the Key to Understanding Human Tribal Behavior?

(A) new fungus has arrived in North America, most likely via introduction by humans, and it is killing bats. This fungus (Geomyces destructans) causes “white nose syndrome,” which was first seen in the U.S. in New York in 2006. Where it met the bats, the fungus spread quickly among roosts, killing nearly all of the little brown bats and other bat species in each of the caves in which it appeared. 

But not all is lost. Although it looked as though the little brown bats and several other species might soon face extinction, at least in some regions and perhaps even in North America, the little brown bats have begun to rebound in some places, albeit modestly. A new paper out this week takes notice of one of the reasons they appear to be rebounding, the bats are avoiding each other. Little brown bats (at least historically) tend to roost in large, groups, one next to the other, bumping fuzzies as it were. But not anymore. More and more, this new study, led by Kate Langwig, a graduate student at Boston University, suggests, the bats are spreading themselves out in their roosting caves, their hibernacula. Once, they clumped, warming themselves around the tiny fires of their bodies. Now, they go it alone.

Interestingly, this little brown bat behavior is precisely what the literature on human behavior, xenophobia and tribalism would have predicted. 

Rinderpest @ number 2

The eradication of smallpox (certified by the WHO in 1979) led to a period of optimism that other diseases would be soon vanquished. I don't think anyone expected that it would be over three decades before another disease fell - Rinderpest declared extinct by the WHO in 2011.

A number of newspapers had nice articles describing both the historical importance of Rinderpest and also the eradication program.

The New York Times made the point that with the disease is relatively unknown in America because with the exception of a brief, contained outbreak in Brazil in 1920, it never reached the Americas. (Rinderpest, Scourge of Cattle, Is Vanquished.)

The Washington Post explains that three things made rinderpest eradicable. Animals that survived infection became immune for life. A vaccine developed in the 1960s by Walter Plowright, an English scientist who died last year at 86, provided equally good immunity. And even though the virus could infect wild animals, it did not have a reservoir of host animals capable of carrying it for prolonged periods without becoming ill. (Rinderpest, or ‘cattle plague,’ becomes only second disease to be eradicated.)

Swimming in sick seas

There was a session on ocean health at last month's Annual Meeting of the American Association for the Advancement of Science (AAAS) in Vancouver, Canada.


A number of news outlets picked up on the news that pathogens of terrestrial animals are killing ocean mammals: Iconic Marine Mammals Are 'Swimming in Sick Seas' of Terrestrial Pathogens

Parasites and pathogens infecting humans, pets and farm animals are increasingly being detected in marine mammals such as sea otters, porpoises, harbour seals and killer whales along the Pacific coast of the U.S. and Canada, and better surveillance is required to monitor public health implications, according to a panel of scientific experts from Canada and the United States.

Between 1998 and 2010, nearly 5,000 marine mammal carcasses were recovered and necropsied along the British Columbia and Pacific Northwest region of the U.S., including whales, dolphins and porpoises, sea lions and otters.

"Infectious diseases accounted for up to 40 per cent of mortalities of these marine animals," says Stephen Raverty, a veterinary pathologist with the Animal Health Centre in the British Columbia Ministry of Agriculture and Lands, and an adjunct professor in UBC's Marine Mammal Research Unit.

"In many cases, the diseases found in these marine mammals have similar or genetically identical agents as those infecting pets and livestock. We don't yet know how these diseases are affecting the health of marine mammals" says Raverty.

After the Rinderpest

Bill Knight is a South African musician who has a whole album about the Rinderpest epidemic that devastated Africa.

The Scene is the Cape Colony border, late 19th century, a terrible plague, the Rinderpest (rather like Foot & Mouth), has decimated the livestock and lives of the Boers, Brits and Amaxhosa alike. The infected animals have to be piled in pits and burned. The land is covered in smoke and weeping.

You can download a free mp3 of the title song , After the Rinderpest, from the Last.FM website.

After the Rinderpest

 

There’s a wicked wind on the smoking ground

All out hopes and dreams, we had to burn them down.

And our poisoned wells took our first and best

Gave our childrens’ lives to the Rinderpest.

 

Sent our youths away to be militarized

And we couldn’t see into their empty eyes.

Would you have the strength, if they confessed

To what they saw, in the wilderness.

 

With a burying pit full of burning beasts

With the crimson coals of the heat beneath.

Holding out our hands to be cauterized

But the Rinderpest left us paralyzed.

 

And a tattooed child full of battle scars

With a heart of iron, hammered hard.

Do we act surprised, as though we never knew

What the sulphur air would have done to you.

 

There are bands of us that have survived

And all we have is how we live our lives.

As we struggle on, we must not forget,

Just what we learned, from the Rinderpest.

NBAF

I spoke too soon. Just two days ago the government cut all construction funding for the new billion dollar National  Biological and Agricultural Defense Laboratory that was planned for Manhattan, Kansas.

Although the cut has occurred largely for budget reasons the
National Research Council will continue its congressionally-mandated study of the facility’s safety. It's actually the second study - an earlier study by National Research Council scientists determined, based largely on the federal government’s data, that there was a 70 percent chance of an accidental release of foot-and-mouth disease from the lab sometime in its projected 50-year lifespan.

Read more here: http://www.kansascity.com/2012/02/13/3427825/budget-puts-kansas-lab-on-shaky.html#storylink=cpy

Ebola in apes

Caregiver at Congo's Virunga National Park wearing a facemask to limit danger of orphan ape being exposed to human diseases.

Originally it was suspected that primates such as gorillas might be the natural reservoir of the ebola virus. It is now thought that this is unlikely and that the reservoir is probably bats. One reason we think that apes are an unlikely reservoir is that they suffer fairly severe outbreaks that can kill a high proportion of the animals, (making it difficult for the virus for persist in this population). (eg Ebola Outbreak Killed 5000 Gorillas in the journal Science in 2006). In other words the virus is spilling over into the ape populations in the same way it occasionally spills over into human populations. Over the last two decades the Zaire strain of Ebola has killed roughly one third of the world's gorilla population and only a slightly smaller proportion of the world's chimpanzees

Just last December a paper in PLoS ONE: Consequences of Non-Intervention for Infectious Disease in African Great Apes highlighted the potentially dire consequences of diseases such as Ebola and SIV's for African Great Apes.

Viral chatter

Virus hunter Nathan Wolfe is outwitting the next pandemic by staying two steps ahead: discovering deadly new viruses where they first emerge -- passing from animals to humans among poor subsistence hunters in Africa -- before they claim millions of lives.

Check out Nathan Wolfe's talk at the 2009 TED conference last year. TED (Technology, Entertainment, Design) invite some of the world's most fascinating thinkers and doers, and challenge them to give the talk of their lives. The best talks and performances are available on their website. You should all check out this talk, it is very interesting, very well presented and hugely relevant to this class.

Davis sent me a link to a New Yorker article from 2010 that covers Nathan Wolfe's work:

Sandrine had just finished preparing the meat for dinner. I asked her if she understood how risky it was to plunge her hands into the intestines of a dead monkey. “Yes,” she said. “I know that bushmeat is dangerous. That it can kill my children.” She was also aware that there had been an outbreak of Ebola recently in Congo. I wondered whether she or her husband had ever seen dead monkeys or gorillas in the forest. She nodded, gazing at the dark foliage as night began to fall. “What did you do when you saw them?” I asked. She turned to me and smiled. “I thanked God, picked them up, and brought them home for dinner,” she said.

Nom Nom Nom

Following on from the post below, here's the Black-footed ferret who likes to snack on prairie dogs and can also succumb to bubonic plague. The black footed ferret is a federally endangered species though and one of the rarest mammals in North America. In 2008 when bubonic plague broke out in the prairie dog colonies ferrets were vaccinated:


In mid-May, the Centers for Disease Control confirmed sylvatic plague in black-tailed prairie dog colonies in the Conata Basin area of Buffalo Gap National Grasslands in southwestern South Dakota. As of late June, about 9,000 acres of prairie dog habitat — including colonies occupied by vulnerable black-footed ferrets — have been infected by the disease, according to U.S. Forest Service mapping. Black-tailed prairie dogs are also being reconsidered for listing under the Endangered Species Act.

To help increase ferret survival during this outbreak, biologists are vaccinating wild ferrets to provide immunity if they become exposed to plague. The plague vaccine was developed for humans by the U.S. Army Medical Research Institute for Infectious Disease and is being tested and modified for animals at the USGS National Wildlife Health Center (NWHC) in Madison, Wisc.

nom nom nom

Prairie dogs are:

a) cute little critters and an important part of the prairie ecosystem

b) a damaging pest of pastures and fields with their digging and such.

Of course the correct answer is c) all of the above. Unfortunately Prairie Dogs are also a host of bubonic plague which gives the anti-prairie dog campaigners (mainly farmers and ranchers) a pretty powerful argument:

"They need to be managed when they are overpopulated, you want to remember, when they get overpopulated, they have a tendency to have bubonic plague. And bubonic plague is contagious to people."

Hence Bill LB473 before the Nebraska Legislature that would give counties the power and duties to carry out a management program to help control the animals.

What is missing from the disease argument though is whether an increase in the levels of bubonic plague in prairie dog populations ever actually leads to cases in humans.

Robert Koch and Rinderpest

The German physician and microbiologist Robert Koch is most famous for developing the germ theory of disease and for proposing that ‘one germ causes one disease- every disease has its specific germ’.

Koch and his pupils found the organisms responsible for tuberculosis, anthrax, diphtheria, typhoid, pneumonia, gonorrhoea, cerebrospinal meningitis, leprosy, bubonic plague, tetanus, and syphilis, among others.

In 1896 Koch was brought to South Africa by the Cape Government to investigate and find a cure for cattle plague, or Rinderpest, which had broken out during the last decade of the 19th century. The epidemic affected most of southern African, but it hit the Transvaal and Northern Cape particularly hard.

Although he did not identify the cause of this disease, he succeeded in limiting the outbreak of it by injection into healthy farm-stock of bile taken from the gall bladders of infected animals. He announced the discovery of his vaccine on 10th February 1897.

After the Rinderpest

Whilst there is, of course, a death metal band called Rinderpest, with a song called Rinderpest, I couldn't make much headway with the 'lyrics'. Let me know if you have better luck.

More interestingly there is a South African musician who has a whole album about the Rinderpest epidemic that devastated Africa.

The Scene is the Cape Colony border, late 19th century, a terrible plague, the Rinderpest (rather like Foot & Mouth), has decimated the livestock and lives of the Boers, Brits and Amaxhosa alike. The infected animals have to be piled in pits and burned. The land is covered in smoke and weeping.

It's not easy to find but you can download an mp3 of the title song , After the Rinderpest, from the Last.FM website.

After the Rinderpest

 

There’s a wicked wind on the smoking ground

All out hopes and dreams, we had to burn them down.

And our poisoned wells took our first and best

Gave our childrens’ lives to the Rinderpest.

 

Sent our youths away to be militarized

And we couldn’t see into their empty eyes.

Would you have the strength, if they confessed

To what they saw, in the wilderness.

 

With a burying pit full of burning beasts

With the crimson coals of the heat beneath.

Holding out our hands to be cauterized

But the Rinderpest left us paralyzed.

 

And a tattooed child full of battle scars

With a heart of iron, hammered hard.

Do we act surprised, as though we never knew

What the sulphur air would have done to you.

 

There are bands of us that have survived

And all we have is how we live our lives.

As we struggle on, we must not forget,

Just what we learned, from the Rinderpest.

More viral chatter

Virus hunter Nathan Wolfe is outwitting the next pandemic by staying two steps ahead: discovering deadly new viruses where they first emerge -- passing from animals to humans among poor subsistence hunters in Africa -- before they claim millions of lives.

Check out Nathan Wolfe's talk at the 2009 TED conference last year. TED (Technology, Entertainment, Design) invite some of the world's most fascinating thinkers and doers, and challenge them to give the talk of their lives. The best talks and performances are available on their website. You should all check out this talk, it is very interesting, very well presented and hugely relevant to this class.

Whale snot

Sandwiched between 'How to make a toddlers guitar hero controller' and 'How to make a cardboard horse to hide a paper tiger' (huh?) on the Make Magazine blog is the equally fascinating 'How to collect whale snot using an RC helicopter'.

With a growing interest in wildlife diseases and a desire to non-destructively collect samples from whales scientists have been interested in collecting the exudates from whale blowholes.

At the simplest level, as they explain this involves three steps:

• Find whale.
• Hold petri dish over blowhole to intercept spout.
• Return to lab, enjoy sample.

Of course holding the petri dish over the blowhole is the tricky step. Enter the RC helicopter.

Scientific report here:
"A novel non-invasive tool for disease surveillance of free-ranging whales and its relevance to conservation programs"

I've said this before, but I'll say it again, how can you not be a biologist when you could get to do things like this for a living?

Viral chatter

Virus hunter Nathan Wolfe is outwitting the next pandemic by staying two steps ahead: discovering deadly new viruses where they first emerge -- passing from animals to humans among poor subsistence hunters in Africa -- before they claim millions of lives.

I try to keep the blog new and fresh but sometimes a past post is simply so relevant and interesting that I can't resist a repeat.

Check out Nathan Wolfe's talk at the TED conference earlier this year. TED (Technology, Entertainment, Design) invite some of the world's most fascinating thinkers and doers, and challenge them to give the talk of their lives. The best talks and performances are available on their website. You should all check out this talk, it is very interesting, very well presented and hugely relevant to this class.

Viral Chatter

Virus hunter Nathan Wolfe is outwitting the next pandemic by staying two steps ahead: discovering deadly new viruses where they first emerge -- passing from animals to humans among poor subsistence hunters in Africa -- before they claim millions of lives.

Check out Nathan Wolfe's talk at the TED conference earlier this year. TED (Technology, Entertainment, Design) invite some of the world's most fascinating thinkers and doers, and challenge them to give the talk of their lives (in 18 minutes). The best talks and performances are available on their website. You should all check out this talk, it is very interesting, very well presented and hugely relevant to this class.

The cost of eliminating Rinderpest

I was still looking for an estimate of the total cost of Rinderpest elimination when I came across this Science article: RINDERPEST: Driven to Extinction from last year, which provided just the estimate I was looking for:

It's impossible to tease out exactly what had been spent in the fight against rinderpest, but Roeder estimates that since 1986, international donors and participating countries spent approximately $610 million on animal health in Africa and Asia, primarily targeting rinderpest but covering other diseases and infrastructure. One FAO estimate puts the benefits of rinderpest eradication at $1 billion annually in Africa alone. The additional $10 million or $12 million needed for the remaining countries to complete the accreditation process "would be a small price to pay for finalizing the eradication of this devastating disease," he says. With just a final push, rinderpest could officially join smallpox as a disease of the past.

The article is a nice, and quite short summary of the elimination program. The link to the article will probably only work from campus computers. Off campus you will need to log on to the libraries proxy server.

Scary Squirrel World

Until we know more about TSE's it would seem wise to hold off on all those wild animal brain based delicacies. It seems likely that many organisms may have such TSE's but if the species lifespan is only a few years it may be much shorter than the time it takes the prion protein to multiply up to the level that causes symptoms.

Following the observation of an unusual cluster of Creutzfeldt-Jakob cases in Kentucky, the suggestion was made that these may have arisen due to the consumption of squirrel brains - apparently a regional delicacy.

These observations, together with recent concerns about the transmission of a unique encephalopathy in man believed to be related to bovine spongiform encephalopathy led us to examine the possible association of eating squirrel brains with CJD in rural Kentucky, where eating squirrel and other small game is not uncommon. Culinary preparations include scrambling the brains with eggs or putting them in a meat and vegetable stew referred to as “burgoo”.

Normally I dislike the very dry style of scientific writing but this paper, Creutzfeldt-Jakob Disease and eating squirrel brains, contains the following gem:
'(C)aution might be exercised in the ingestion of this arboreal rodent.'

Following Mike Huckabee's revelation that he ate squirrel (cooked in a popcorn popper!) in college Slate investigated.

Not just for doctors waiting rooms.....

Placid under sedation, a juvenile rhesus macaque yields biological samples that could show him to be infected with human diseases such as tuberculosis or measles. Similarly, primates can pass pathogens to humans—potentially touching off pandemics.

If you'd like to read a little more about zoonotic diseases National Geographic had a great article a little over a year ago: Deadly Contact: How Animals and Humans Exchange Disease

We will return to this topic, and the issue of bushmeat, when we talk about Ebola.

Sea otters

The sea otter and toxoplasmosis research at UC Davis I mentioned is funded by NOAA (National Oceanic and Atmospheric Administration), part of the Department the Interior. They have a nice report on the work at the NOAA website here.