A Host Of Difference Between SARS & MERS

 

Photo Credit NIAID

 

# 8630

 

Given that both diseases are caused by a previously unknown coronavirus, both appear to originate from an unusual zoonotic source, and both (so far) flourish and spread best in a hospital environment, it is tempting to believe that the MERS outbreak will follow pretty much the same course as did SARS in 2003.

 

Once that threat was recognized, quarantines were established, strict infection control procedures were implemented, and SARS was brought under control in a matter of months.  

 

In the end SARS turned out to be a brightly burning, but relatively brief, epidemic that infected about 8,000 people – mostly in Asia - killing roughly 10% of them. But through a concerted international public health response, it was eventually contained.

 

While apparently the result of a zoonotic spillover, the exact host from which SARS entered the human population has never been firmly established.  Many place the  blame on the `wild flavor’ restaurants of Guangdong province - where customers could dine on exotic animals that were often kept alive, and in filthy cages, in the back kitchens awaiting their fate.   

China’s belated response to the outbreak led to the shuttering of hundreds of these restaurants, the temporary closing of many `live markets’ dealing in `exotics’, and the culling of a prime zoonotic suspect – the Palm Civet (see  A Civets Lesson).  Something in this mix apparently worked.

 

Whatever its zoonotic origin, we were lucky that the SARS coronavirus wasn’t more common and widespread in the wild.  As a result, the SARS virus disappeared and has not remerged in more than a decade, although similar coronaviruses have been detected in bats in Asia and the Middle East. 

 

With MERS-CoV, while similar to the SARS virus in many ways, we may not be as lucky.

 

MERS-CoV appears to be endemic in a large (and geographically broad) population of camels – animals that are not only greatly beloved in the Middle East, but are often in close contact with humans (see Saudi Ministry Of Agriculture Issues Warnings On Camels). 

While the exact role of camels in the spread of the disease has not been established, many researchers believe that they are responsible for intermittently introducing the virus to the human population (see CIDRAP NEWS WHO sees camels as MERS source, but route uncertain).

 

With SARS, once the zoonotic source was eliminated, solid infection control and quarantines were able to contain and quash the outbreak in humans. 

 

If, as suspected, camels are the animal host through which the MERS virus gets into the human population  -  the likelihood is we will continue to see fresh introductions of the virus going forward. 

 

Culling, which has previously been employed with chickens, ducks, and civets would be an impractical and extremely unpalatable option for millions of dromedaries, and a vaccine – assuming one would work with camels - may not be available for months or even years.  

 

The only genuinely good news with MERS is that while human-to-human transmission is well documented, it doesn’t (yet) seem to transmit as readily as SARS did a decade ago.  And it is far less transmissible than most other respiratory viruses (colds, flu, etc.).

 

In the short run, consistent strict infection control protocols and the proactive quarantining of exposed individuals – both used successfully to combat SARS - are likely to effectively contain localized outbreaks.  

 

But unlike SARS, MERS-CoV has the potential to continually reseed itself into the human population. Localized outbreaks can therefore peak, be brought under control, only to fueled by another spillover event.

 

Meaning that even if MERS never gains an iota of additional transmissibility, it is unlikely we will see it fade from the international stage anytime soon.

Referral: Dr. Mackay On Baboon Testing For MERS-CoV

 

 

Photo Credit - Wikipeda

 

# 7568

 

The hunt for a primary (and additional suspected intermediate) hosts for the MERS coronavirus in the Middle East is a major focus of the epidemiological investigation - and while bats and camels remain high on the suspect list – other species may carry (and possibly transmit) the virus as well.

 

We simply don’t know much about the reservoir ecology of MERS-CoV, and probably won’t until a good deal more serological testing can be done on a variety of animal species.

 

Dr. Christian Drosten (part of the research team behind Lancet: Camels Found With Antibodies To MERS-CoV-Like Virus) – in an article published earlier this year in Nature’s Emerging Microbes & Infection (Virus ecology: a gap between detection and prediction) - describes the rationale behind such research.

 

For any virus, the identification of a mammalian reservoir is highly relevant because the ‘fitness valley’ that viruses need to cross for the conquest of new hosts is shallow if the hosts are genetically related.

 

(Note: Dr. Drosten’s article is well worth reading in its entirety.)

 

If you are looking for `genetically related hosts’ then higher primates certainly ought to be on your list. While you might not automatically think of the Arabian Peninsula as being home to such primates, troops of Hamadryas Baboons are commonly found across semi-desert regions of Ethiopia, Somalia, Yemen, and southern Saudi Arabia.

 

Accordingly, Dr. Ian Mackay takes a look at baboons as a species worth checking for the MERS coronavirus in his Virology Down Under blog. 

 

Follow the link to read . . .

 

Baboons and MERS-CoV....

This post is based on @dspalten and his interest materials and analyses

Twitter yields all sorts of things to think about. Since the Lancet article on MERS-CoV-like antibody reactivity in dromedary camel sera, one tweeter has been a strong proponent of testing baboons, an African and Arabian old world, omnivorous monkey, for MERS-CoV.

 

(Continue . . . )

A Disease Detective Story: Figuring Out Where EEE Spends The Winter

 

 

# 6606

 

 

While West Nile Virus infections are far more common (see DVBID: West Nile Infections Continue Record Pace), the Eastern Equine Encephalitis (EEE) virus elicits considerable concern because of its high fatality rate (30%+) and the large number of survivors who suffer ongoing neurological impairment.

 

Most years, only about 6 cases (range: 3—21) of human EEE are reported in the United States.

 

But this year – just as we’ve seen with WNV – is an unusually active year, and thus far the USGS is reporting 12 cases of EEE.

 

 

Given the devastating effects of infection in humans, and the fact that there is no vaccine available for humans to prevent it, learning about the ecology of the EEE virus is of particular importance.

 

We know that the natural hosts for the EEE virus are songbirds, which can become infected usually without suffering ill effect. The primary vector that spreads the virus among birds is the female Culiseta melanura mosquito (males don’t bite).

 

 

After an infected mosquito feeds on a bird, the bird becomes infected and the virus begins reproducing. After a few days - and for only a few days - the bird’s bloodstream amplifies the virus enough to infect subsequent mosquitoes that feed on it.

 

Culiseta melanura, however, isn’t usually attracted to bite humans.

 

So it requires a secondary type of mosquito - one that isn’t quite as picky a feeder - such as the Aedes albopictus or  Coquillettidia perturbans  `salt and pepper’ mosquito, to bite an infected bird in order to move it into the equine or human population.

 

The Transmission cycle is illustrated by the following graphic from the CDC.

 

Humans and horses don’t develop a high enough viral EEE titer in their bloodstream to pass on the virus if they are subsequently bitten by a mosquito, so they are considered to be `dead-end hosts’.

 

This explains the transmission cycle of the virus, but for one rather conspicuous hole in the equation.

 

Since birds are only viremic for a few days after being bitten, and since mosquitoes die out for several months during the winter  . . . . how does the virus manage to return each spring and summer?

 

For years scientists have suspected there had to be another host in the wild that could provide the EEE virus a safe place to overwinter.

 

But it would have to be one that could carry a high enough viral titer throughout the winter in order to reseed the virus in mosquito populations the following spring.

 

All of which brings us to some fascinating research that points to snakes – cottonmouths and copperheads, in particular – as being the winter residence of the EEE virus. 

 

Cottonmouth – Credit Wikipedia

 

This new study, which appears in the American Journal of Tropical Medicine and Hygiene, provides strong support for the idea that hibernating snakes serve as a bridge for the EEE virus to make it from one year to the next.

 

Detection of Eastern Equine Encephalomyelitis Virus RNA in North American Snakes

Andrea M. Bingham, Sean P. Graham, Nathan D. Burkett-Cadena, Gregory S. White, and Thomas R. Unnasch 

ABSTRACT

The role of non-avian vertebrates in the ecology of eastern equine encephalomyelitis virus (EEEV) is
unresolved, but mounting evidence supports a potential role for snakes in the EEEV transmission cycle, especially as over-wintering hosts.

 

To determine rates of exposure and infection, we examined serum samples from wild snakes at a focus of EEEV in Alabama for viral RNA using quantitative reverse transcription polymerase chain reaction.

 

Two species of vipers, the copperhead (Agkistrodon contortrix) and the cottonmouth (Agkistrodon piscivorus), were found to be positive for EEEV RNA by using this assay. Prevalence of EEEV RNA was more frequent in seropositive snakes than seronegative snakes. Positivity for the quantitative reverse transcription polymerase chain reaction in cottonmouths peaked in April and September. Body size and sex ratios were not significantly different between infected and uninfected snakes.

 

These results support the hypothesis that snakes are involved in the ecology of EEEV in North America, possibly as over-wintering hosts for the virus.

(Continue . . . )

 

The entire article is available online, and is a fascinating disease detective story . . . well worth reading in its entirety.

 

While probably not the preferred target for hungry mosquitoes - during the early spring and late fall when other blood meal sources may be in short supply - mosquitoes do feed on snakes.

 

They bite – not through their tough skin – but through the soft membranes around the snake’s eyes.  

 

Beyond discovering antibodies to the EEE virus in 35% of the cottonmouths sampled, the also found a number of snakes positive (via qRT-PCR) for the EEE virus.

 

This, they believe, is the first time that the active EEE virus has been documented in wild-caught snakes.

 

Previous tests had showed that snakes experimentally infected with the EEE virus remain viremic only for 7 to 10 days before they clear the infection – not enough time for the virus to overwinter.  

 

But now it appears that when a snake hibernates, it can carry the virus over the winter, and can likely reintroduce it to mosquitoes the following spring.

 

All of which introduces an interesting notion regarding control of the virus. Normally spraying for mosquitoes doesn’t begin until EEE starts showing up in mosquito surveillance traps, horses, or worse . . . humans.

If spraying were conducted during the early spring in swampy areas where mosquitoes and snakes are likely to meet - it might be possible to interrupt this annual cycle - and thus thwart the virus’s reintroduction to the mosquito and bird population.

 

 

As the abstract states, this study supports the hypothesis that snakes are the `bridge’ host for the EEE virus, but there is still more research needed. 

 

For more on this story Maggie Fox of NBC News has a good report, along with some comments from the lead author of the study; Dr. Thomas Unnasch of the University of South Florida.

 

Snakes may harbor deadly virus

 

And for more on the EEE virus, you may wish to revisit some of these earlier blogs.

 

MMWR: Arboviral Disease Surveillance – 2010

ASTMH: Dengue and Insect-Borne EIDs In The US

Eastern Equine Encephalitis (EEE)

EID Journal: Guinea Pigs As Reservoirs For Influenza

 

 

# 6369

 

 

From the CDC’s EID Journal we’ve a new study that looks at influenza infections in farm-raised guinea pigs in Ecuador, that provides several surprising results.

 

Ferrets and mice are often used in influenza research, but neither is truly ideal.

 

So in recent years a number of researchers have looked at guinea pigs as possible model mammalian host for influenza virus studies (see PNAS The guinea pig as a transmission model for human influenza viruses by Peter Palese et al. 2006).

 

The success in using guinea pigs in lab studies has led some scientists to wonder just how guinea pigs might fit into the hosting and spread of flu viruses outside of the laboratory.

 

Which brings us to a dispatch (again from Peter Palese et al.) that was published yesterday in the EID journal called:

 

Dispatch

Influenza Virus Infection in Guinea Pigs Raised as Livestock, Ecuador

Victor H. Leyva-Grado, Samira Mubareka, Florian Krammer, Washington B. Cárdenas, and Peter Palese

Abstract

To determine whether guinea pigs are infected with influenza virus in nature, we conducted a serologic study in domestic guinea pigs in Ecuador. Detection of antibodies against influenza A and B raises the question about the role of guinea pigs in the ecology and epidemiology of influenza virus in the region.

 

 

Guinea pigs are raised and used as food in parts of South America (Peruvians reportedly consume more than 65 million of them each year, and they may also be found on the menu in Bolivia, Ecuador, and Columbia).

 

While the consumption of guinea pigs may seem an unusual culinary choice to many of us, it is so entrenched in the Andean culture that in 1753 - when Marcos Zapata painted his version of `The Last Supper’ for Peru (which now hangs in The Cathedral Of Cusco ) - he depicted Christ and the Apostles dining on a platter of cuy, or guinea pig.

Photo Source – Wikipedia.

 

But I digress . . .

 

Most of these animals are raised on small farms, and often in close contact with other livestock as well as humans.

 

Given these conditions, and their propensity for hosting and spreading influenza in laboratory studies, a seroprevalence study was undertaken to see how widespread influenza infection among guinea pigs might be outside of the laboratory.

 

This study examined blood samples from 40 guinea pigs taken from 3 locations across Ecuador, and subsequently found evidence of previous Influenza A infections in a unusually large number of them.

 

The surprises (of which there were several) included:

 

• The high percentage of positive influenza A samples (50% H1, 45% H3)
• The detection of several (n=14)animals carrying antibodies to an H5 virus
• And perhaps the biggest surprise of all – finding evidence of influenza B infections (previously only thought to infect humans) in 27 of the 40 samples tested.

 

 

An earlier seroprevalence study of influenza A among humans in Ecuador showed a seroprevalence of H1 (5.1%) and H3 (5.5%) -  about 1/10th that found in these guinea pigs.

 

The authors suggest that the way these animals are raised (caged together and in close quarters) may facilitate the spread of influenza. 

 

The discovery of H5 antibodies is intriguing, but since this study only tested only for seroreactivity to parts of the H5 virus, further study will be required to identify and quantify the prevalence of avian influenza viruses in this population.

 

And the last finding - that of Influenza B in roughly 2/3rds of the samples – support the idea that this type of influenza can be readily transmitted from humans to other hosts.

 

The authors write:

 

Further studies are needed to isolate and characterize the type B influenza virus present in the population of guinea pigs to determine if there has been an adaptation to the new host or if the guinea pig is only a transient reservoir for the human virus.

 

The authors conclude this dispatch by stating:

 

We did not determine whether guinea pigs are an incidental host for influenza virus infection or, if instead, the virus has been adapted to these animals or if guinea pigs are a natural reservoir for some influenza viruses. To this end, virus isolation and characterization would be necessary to determine the virus strains circulating in this population. In the laboratory, guinea pigs are infected and efficiently transmit influenza viruses to naive hosts without showing any overt clinical signs of disease (1). Therefore, further studies are needed to address the specific role of guinea pigs raised as livestock in the ecology and epidemiology of influenza viruses in the region.

 

 

For more details on the methods used, the full text is available online at this link.

 

While this research might seem a bit obscure to all but the most ardent infectious disease geeks, it serves to show just how little we still know about influenza viruses and their host range,  and that there are still plenty of surprises waiting out there yet to be uncovered.

Egypt: H5N1 Isolated In Donkeys

 

 

 

# 4498

 

 

The ability of the H5N1 bird flu virus to jump species has been well documented over the past few years. While its natural host is aquatic waterfowl, we’ve seen H5N1 infections in cats (including tigers), dogs,  martens, civets, and of course humans.

 

Researchers have successfully infected cattle with the H5N1 virus, along with ferrets and mice for testing.

 

Viruses generally adapt to a fairly narrow range of species.  Horse viruses generally attack equines, and not say, cats and dogs.   Cat viruses tend to attack felines, and not birds.   Many bird viruses only infect avian species. 

 

The species that a virus will infect is known as its host range.  And while usually limited, it isn't always the case.  Rabies is a good example of a virus that can infect a wide host of species.

 

The H5N1 virus continues to surprise in this regard, showing up in an increasingly wider range of non-avian hosts.

 

Today, in the Journal of Biomedical Science, we have the first report that I’m aware of showing the isolation of the H5N1 virus in Donkeys.

 

A hat tip to Treyfish on FluTrackers for posting an article that led me to this study.

 

 

 

 

Isolation and characterization of highly pathogenic avian influenza virus subtype H5N1 from donkeys

Ahmed S Abdel-Moneim , Ahmad E Abdel-Ghany  and Salama AS Shany

Journal of Biomedical Science 2010, 17:25doi:10.1186/1423-0127-17-25

Published:
14 April 2010

Abstract (provisional)

Background

The highly pathogenic H5N1 is a major avian pathogen that crosses species barriers and seriously affects humans as well as some mammals. It mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences.

Methods

Nasal swabs were collected from donkeys suffered from respiratory distress. The virus was isolated from the pooled nasal swabs in specific pathogen free embryonated chicken eggs (SPF-ECE). Reverse transcriptase polymerase chain reaction (RT-PCR) and sequencing of both haemagglutingin and neuraminidase were performed. H5 seroconversion was screened using haemagglutination inhibition (HI) assay on 105 donkey serum samples.

Results

We demonstrated that H5N1 jumped from poultry to another mammalian host; donkeys. Phylogenetic analysis showed that the virus clustered within the lineage of H5N1 from Egypt, closely related to 2009 isolates. It harboured few genetic changes compared to the closely related viruses from avian and humans. The neuraminidase lacks oseltamivir resistant mutations. Interestingly, HI screening for antibodies to H5 haemagglutinins in donkeys revealed high exposure rate.

Conclusions

These findings extend the host range of the H5N1 influenza virus, possess implications for influenza virus epidemiology and highlight the need for the systematic surveillance of H5N1 in animals in the vicinity of backyard poultry units especially in endemic areas.

 

There is a link to a provisional PDF file HERE, but as of this writing, the link returns an error.   Hopefully the entire report will be online soon.

Mixing Vessels For Influenza

 

 

 

# 4228

 

 

My thanks to Helen Branswell for alerting me (via her Twitter feed) to this article in The Economist about research conducted by two scientists at the San Diego Zoo’s Institute for Conservation Research on which animal species are likely to contract different types of influenza.

 

 

Influenza and wildlife

Mix and match

Jan 7th 2010

From The Economist print edition

Which animal species are most likely to get flu?

Science Photo Library

What, me?

THE scientific value of zoos is sometimes called into question, but Mark Schrenzel and Bruce Rideout, two experts on wildlife diseases who work at San Diego Zoo’s Institute for Conservation Research, have just shown the value of having a wide range of animals to hand for study. They have been looking at which species might act as reservoirs for influenza viruses and—worse, from the human point of view—which might act as “mixing vessels” in which new strains of virus are generated.

(Continue . . . )

 

New strains of influenza come about from reassortment, or the mixing and matching of genetic material between two compatible flu strains in a shared host. 

 

 

While any host (human, swine, avian) could produce a reassorted virus, hosts (like pigs) that are susceptible to a wider range of viruses are thought to be more likely to serve as an efficient mixing vessel.

 

 

Human adapted influenza have an RBD - Receptor Binding Domain (the area of its genetic sequence that allows it to attach to, and infect, host cells) that `fit’ the receptor cells commonly found in the human upper respiratory tract; the alpha 2,6 receptor cell.  

 

Avian adapted flu viruses bind preferentially to the alpha 2,3 receptor cells found in the gastrointestinal tract of birds. 

 

While there are some alpha 2,3 cells deep in the lungs of humans, for an influenza to be successful in humans, it needs to bind to the a 2,6 receptor cell.  

 

 

(Very Simplified Illustration of RBDs)

 

Some mammalian hosts (like pigs) have both types of receptor cells, and therefore, increase the range of influenza viruses to which they are susceptible.   And that, in turn, increases the odds that they could host two different viruses at the same time, and help facilitate a reassortment of two flu viruses into a new hybrid.

 

Drs. Schrenzel and Rideout at the San Diego Zoo have examined 60 different species of small mammals, and have determined that several carry the type of receptor cells (a2,3) favored by the H5N1 avian flu virus; including opossums, the Arctic Fox, and the Chinese wolf.

 

Additionally, we’ve seen H5N1 infections among dogs, cats, civets, raccoons, martens, and – of course – humans.   And researchers have successfully infected cattle with the H5N1 virus, along with ferrets and mice for testing.

 

Over the years, scientists have openly wondered about possible mammalian reservoirs of the virus, which could help explain how the virus can be reintroduced to an area after massive poultry cullings have taken place.  

 

The list of potential hosts is likely to continue to grow.

 

Schrenzel and Rideout have also identified a handful of small carnivores that carry both the a2,3 and a2,6 receptor cells, making them potential mixing vessels.   These include the Persian leopard and the North American striped skunk.

For more on mammalian and avian hosts for influenza, you wish to revisit these blogs. 

 

Japan: Bird Flu Antibodies Found In Raccoons

Reservoir Ducks

Reservoir Dogs (Cats, Foxes, and Raccoons)

 

And for more on RBDs, the following essays might be of interest.

 

Study: H1N1 Receptor Binding

RBD: Looking For The Sweet Spot

Receptor Binding Domains: Take Two

 

 

While we are learning more about influenza viruses, and the hosts they inhabit, we obviously have a long way to go.     The novel H1N1 and H5N1 viruses have rewritten the science text books over the past five years, and more rewrites are likely in store.

US: Dog Tests Positive For H1N1

 

 

# 4181

 

 

In November, we began hearing reports of dogs in China that had tested positive for the novel H1N1 virus.  The first hint came from a CTV newscast (see China Worries Over Species Jumping H1N1) that I blogged about on November 11th.

 

On November 28th, we received more confirmation (see China Reports 2 Dogs With H1N1) with this news report from Xinhua News.

 

China urges intensified supervision on A/H1N1 flu in animals

www.chinaview.cn  2009-11-28 09:43:42

BEIJING, Nov. 28 (Xinhua) -- China's Ministry of Agriculture has called for intensified monitoring and investigation of A/H1N1 flu in animals after two samples from sick dogs were tested positive for the virus.

 

The veterinary clinic of College of Veterinary Medicine at the China Agricultural University reported Wednesday that two out of 52 samples from sick dogs were tested positive for A/H1N1 flu virus, the ministry said late Friday.

 

While conventional wisdom has been that dogs and cats are not normally susceptible to `human-adapted’ influenza, if you blog about influenza long enough – you stop being surprised when the `rules’ are bent.

 

Cats, after all, we were not thought likely to be susceptible to the novel H1N1 virus  either . . .  until, that is, reports of infected cats began to come in a little over two months ago.

 

Followers of the avian influenza story, of course, know that dogs and cats have both been infected by the H5N1 virus.

 

Dr. C.A. Nidom demonstrated in 2006 that of 500 cats he tested in and around Jakarta, 20% had antibodies for the bird flu virus.   For an overview of a number of other cases, see Apparently They Didn't Get The Memo.

 

We’ve not heard of dogs being infected by the H1N1 virus before, although there have been reports of dogs being infected by the H5N1 avian flu.   See also Study: Dogs Can Shed H5N1 Virus.

 

Of course, H5N1 is avian flu, with different receptor binding domains than human flu.   

 

While it probably happens more often than we know, yesterday the first confirmation of canine infection with the novel H1N1 here in the United States was released by Idexx labs.

 

Here are excerpts from the IDEXX Labs press release

 

INDUSTRY ALERT from IDEXX Reference Laboratories:H1N1 influenza virus infection confirmed in household pets

A dog from the Katonah Bedford Veterinary Center in Bedford Hills, New York, has tested positive for the H1N1 virus on the IDEXX H1N1 Influenza Virus RealPCR™ Test.

 

A 13-year-old dog had a several-day history of not feeling or eating well, a dry cough and a fever on presentation to its veterinarian. The dog was treated for pneumonia and improved with hospitalization and supportive care. The dog tested positive on the IDEXX H1N1 Influenza Virus RealPCR Test. A more detailed case description is available.

Background

In the United States, the H1N1 influenza virus has been confirmed recently as the cause of respiratory disease in several ferrets and cats resulting in more than one death in each of these species. These infections were believed to have been contracted from infected owners. There was an unconfirmed report of dogs infected in China in late November. The case described here is what is believed to be the first reported case of a dog infected with the H1N1 influenza virus in the United States. The dog’s owner had also recently tested positive for H1N1 influenza virus. The Iowa State University Veterinary Diagnostic Laboratory has confirmed independently that the influenza strain is the new pandemic strain circulating in the human population and not a swine-specific H1N1 strain.

(Continue . . . )

 

 

The concern here isn’t so much that dogs or cats will give the virus to humans.  Transmission from pet to owner has not yet been established (although it is certainly possible).  

 

Right now, there are plenty of opportunities to contract the illness from humans, without worrying about getting it from a pet.

 

It is far more likely that a pet will catch this virus from their owner, than the other way around.

 

Apart from the scientific curiosity as to why novel H1N1 should have a wider host range (swine, turkeys, felines, canines, ferrets, etc.) than most influenza viruses, the real concern is over the possibility that H1N1’s promiscuous behavior could lead to the creation of mutated or reassorted strains of the virus.

 

 

Of course, this same mutation could occur in swine, birds, humans, or practically any other host the virus can infect.  

 

So we shouldn’t stigmatize our pets as potential incubators of a mutated virus.  It could just as easily happen in a turkey, a pig, or even your next door neighbor.

 

There is also a theory that states that the more susceptible hosts a virus can find, the less evolutionary pressure it will have to mutate.  

 

If true, the ability of this virus to infect more hosts could be seen as good news.  Of course, it’s just a theory . . .   

 

All of which means we have a lot more to learn about this virus in particularly, and influenza viruses in general, before we can begin to predict how all of this turns out.

 

Stay Tuned.

USDA Listing Of Animals With H1N1

 

 

# 4121

 

 

Over the past couple of months we’ve heard of a number of instances here in the United States, and around the world, of animals infected with the H1N1 2009 pandemic virus.  

 

Today we get a list from the  USDA of animals in the US that have tested positive for the virus.  Aside from humans and swine (16), the USDA lists ferrets (5), cats(3), turkeys (5), and a Cheetah (1) as having contracted the virus.

 

A hat tip to Farmer on FluTrackers for posting this link.

 

(Click to load PDF file)

 

The infection of swine with an H1N1 swine-like virus isn’t unexpected, nor is the susceptibility of ferrets a big surprise.  Ferrets are often used in influenza research because they are susceptible to the virus.

 

The jumping to cats is a bit more surprising, given that the only other flu virus known to affect cats is the H5N1 bird flu.

 

The susceptibility of turkeys, given that research over the summer stated that they were not likely to acquire the virus, is perhaps the biggest surprise (see US: Turkey Farm Reports H1N1).

 

The promiscuous nature of this novel H1N1 continues to raise concerns, something that the Reveres at Effect Measure discussed last week (see Dogs, cats and swine flu's promiscuity).

 

Not included (yet) in the above list is the report today of 2 cats, from different households in Colorado, that have tested positive for the virus.

 

 

CSU treats two cats suffering from swine flu

 

Two cats from different households in Colorado have tested positive for the H1N1 virus, or “swine flu,” according to Colorado State University's Veterinary Diagnostic Laboratory.

 

The cats are expected to recover but their cases serve as a reminder to pet owners to seek treatment for animals that appear to be ill. Veterinarians believe that both cats became ill after a person in their household contracted the virus.

 

The feline cases come after H1N1 has been identified in ferrets, birds and other cats in the United States.

(Continue . . .)

H1N1 Infected Cat Dies In Oregon

 

# 4038

 

Cats, normally, are not affected by human influenza viruses. 

 

Feline Influenza, which can be very serious in cats, is actually a generic term for a  respiratory syndrome caused viruses that are not of the influenza family.

 

Feline influenza syndrome is commonly caused by the feline herpes virus (FHV 1) and feline calicivirus (FCV), neither of which are of the influenza family of viruses.

 

The exception to this has been that we’ve seen many reports of cats in Indonesia, Thailand, and other places that have contracted the H5N1 bird flu virus.   A few blogs on those reports over the years include:

 

Apparently They Didn't Get The Memo

Korea: Cat Death Attributed To Bird Flu

FAO To Study H5N1 Infection In Cats

Cat Got Your Virus?

Up until recently it was assumed that cats were not susceptible to the H1N1 virus.   Over the past 3 weeks, however, we’ve learned of 2 cats that have tested positive for the virus.

A newscast out of China last week (See China Worries Over Species Jumping H1N1) stated that they’ve seen similar infections in that nation, but offered no details.

 

Recent monitoring has found several cases of pigs, cats and dogs infected by the human A/H1N1 flu virus. Experts now fear that close contact between people and animals will increase the danger of mutation. –CCTV News

 

And today we get this report from The DMV Magazine, describing a 3rd cat with the virus.

 

 

H1N1-infected cat dies in Oregon

Nov 18, 2009
DVM NEWSMAGAZINE

Lebanon, Ore. -- A cat testing positive for pandemic H1N1 influenza died, according to the Oregon Veterinary Medical Association.

 

A week after a family member in the Oregon household exhibited influenza-like symptoms, one of the four cats in the household showed signs of labored breathing.

 

The cat's owner brought the 10-year-old male to a veterinarian Nov. 4. The cat presented with a 101.7 temperature and a chest radiograph consistent with pneumonia.

 

After the cat's respiratory rate worsened, the cat was admitted Nov. 5 and treated with oxygen and medication.

 

The cat died Nov. 7.

 

Laboratory results from Oregon State University's Veterinary Diagnostic Laboratory and the National Veterinary Diagnostic Laboratory confirmed the cat was infected with pandemic H1N1.

 

This was the third confirmed case of H1N1 in a cat in the United States, with others surfacing in Iowa and Utah.

 

 

Viruses generally adapt to a fairly narrow range of species.  Horse viruses generally attack equines, and not say, cats and dogs.   Cat viruses tend to attack felines, and not birds.   Bird viruses usually only infect avian species.

 

The species that a virus will infect is known as its host range. 

 

And while usually limited, it isn't always the case.  Rabies is a good example of a virus that can infect a wide host of species.

 

The H1N1 virus is turning out to be fairly promiscuous. It has turned up in swine (no surprise), humans, turkeys, ferrets, cats, and is rumored in china to have affected dogs.  

 

All of which has scientists paying close attention to see what this virus will do next.

China Worries Over Species Jumping H1N1

# 3996

 

 

A video report from CCTV (China Central Television) news tonight where concerns over species jumping to pigs, cats, and according to this report . . . dogs, have experts in China concerned over the potential for the H1N1 virus to mutate.

The newscaster is in English, although the interview with Zhong Nanshan, hero of the SARS outbreak of 2003 and a highly respected respiratory disease specialist, is in Chinese with an English translation.

 

We’ve not heard of dogs being infected by the H1N1 virus before, although there have been reports of dogs being infected by the H5N1 avian flu.   For now, until we can get some details, I’m not quite ready to embrace the canine H1N1 species jump.

 

The concern is, particularly in rural parts of china where many people live in close proximity to animals, that a flu virus could mutate, or reassort in an animal host, then spread to humans.

Of course, a flu virus can mutate or reassort in a human host, too.  Other species just add more opportunities, and perhaps a wider range of viruses for the H1N1 virus to encounter.

 

While we know mutations and reassortments happen, they obviously don’t happen easily or often.  Otherwise we’d be hip deep in new viruses all of the time.   Still, it is a legitimate concern and worthy of our attention.

 

A hat tip to Tonka on FluTrackers for posting this link.

 

 

Experts warn of possible A/H1N1 mutation

2009-11-11 13:25 BJT

Medical experts are warning that the A/H1N1 flu has entered a period of high frequency and easy transmission. And with fresh cases of pigs infected by the virus in Hong Kong and Taiwan, experts say the possibility that the virus will mutate is growing.

 

Recent monitoring has found several cases of pigs, cats and dogs infected by the human A/H1N1 flu virus. Experts now fear that close contact between people and animals will increase the danger of mutation. China's Ministry of Health reported 30 fatal cases on the mainland as of Monday, out of nearly 60 thousand confirmed cases. It said the increase in infections will inevitably result in additional severe cases. Experts call for a timely response each time a case is confirmed, to prevent the illness from worsening.

 

Dr. Zhong Nanshan, head of Chinese Medical Association, said, "Because when the virus harms the lungs, there is a high possibility of breathing difficulty. It is different from the usual pneumonia. And there will be great difficulty treating such patients, even though they are young and healthy. The reason for this is unclear yet, but what we can do is get vaccinated, and go to the hospital as soon as possible when suffering from a continuous fever. "

Iowa: Cat Tests Positive For H1N1

 

# 3952

 

From the Iowa Department of Public Health, a report of a pet cat that contracted the H1N1 virus, presumably from it’s servants . . . err, owners.

 

I’ve seen reassurances in the popular press for the past few months that dogs and cats were not susceptible to this flu virus, but as we’ve seen with other strains (including H5N1), cats can and do catch the flu.

 

Which proves that the one thing you can say about influenza viruses is; Never say `never’.

 

A hat tip to @scifri and @ICAV on twitter for announcing this link.

 

 

 

Protecting Pets from Illness

The Iowa Department of Public Health (IDPH) and the Iowa Department of Agriculture and Land Stewardship (IDALS) remind Iowans that in addition to protecting their families, friends and neighbors from the spread of the 2009 H1N1 influenza virus, it’s important to remember to protect family pets from the illness, as well. People who are sick with H1N1 can spread the virus not only to humans, but to some animals.

 

The Departments are sharing this message following the confirmation of a case of H1N1 in an Iowa cat.

 

The 13-year-old indoor cat in Iowa was brought to the Lloyd Veterinary Medical Center at Iowa State University’s College of Veterinary Medicine, where it tested positive for the H1N1 virus. The diagnosis is the culmination of collaborative efforts between IDPH, Iowa State University College of Veterinary Medicine, Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, USDA, and IDALS Animal Industry Bureau.

 

“Two of the three members of the family that owns the pet had suffered from influenza-like illness before the cat became ill,” said IDPH Public Health Veterinarian, Dr. Ann Garvey. “This is not completely unexpected, as other strains of influenza have been found in cats in the past.” Both the cat and its owners have recovered from their illnesses.

 

People can keep their pets healthy by washing hands, covering coughs and sneezes, and minimizing contact with their pets while ill with influenza-like symptoms. If your pet exhibits signs of a respiratory illness, contact your veterinarian.

 

“Indoor pets that live in close proximity to someone who has been sick are at risk and it is wise to monitor their health to ensure they aren’t showing signs of illness,” said Dr. David Schmitt, State Veterinarian for Iowa.

 

For more information about H1N1, visit www.idph.state.ia.us/h1n1/ or call the Iowa Influenza Hotline at 1-800-447-1985.