Hello, everyone. My name is Catherine Queenberry. I'm the service head of the Avian Exotic Pet Service and also the chief medical officer at the Animal Medical centre in New York.

And I'm gonna talk to you today about zoonotic diseases and exotic pet medicine. So we're gonna start off talking about the One Health initiative and this was an initiative that was first introduced in the 1960s by A veterinary epidemiologist named Calvin Schwab, and it has rapidly become a very important initiative worldwide, where we recognise animals as a source of recent And historical human pathogens, and we all know that's so true today with the SARS COVID-2. Birds.

Small mammals and reptiles we know carry zoonotic disease of varying risk to humans. So these are some of the outbreaks that we have known about just in the last probably 20 years or so. We first there was a swine flu.

Then, of course, back probably in the And probably about 10 years ago, we had the bird flu epidemic and that was a huge crisis at that time. Then we have the SARS epidemic that started a a little after that, and now, of course, we're dealing with the COVID too. Now, there's legal issues to consider here.

We wanna make sure that we're informing clients of Any potential infectious disease risks, a failure to advise clients, can cause a problem. So we need to really be aware as veterinarians of what these disease risks are. And we also need to document it in medical records if we're suspicious of any sort of zoonotic disease.

So today, I can't really, of course, go into all the, the disease risk that we're dealing with for zoonotic disease, but I'm gonna try to concentrate on a few of the more common ones. The ones that most people should know about in exotic animal practise. So the first one I'm gonna talk about is chlamydia.

Now, chlamydia, we've known anybody that has done exotics for a while is aware of chlamydia. You should know about chlamydia in birds. Chlamydia was probably 10, in the last 10 years.

They changed the the nomenclature to chlamydophyla. Now it's known again as chlamydia, and the disease, of course, in birds is called psittaosis or ornithosis, . And, or, or the disease state of carrying chlamydia, and the agent that we're most concerned about or we most know about, I should say, is chlamydia sitici.

Now, what are chlamydia? Chlamydia are bacteria. They're gram-negative bacteria.

They are obligate intracellular parasites. They contain both DNA, RNA, and ribosomes, so they are true bacteria. They consist in two forms, the elementary body, which is the small infectious form, and then the reticular body, the reticulate body, which is the non-infectious replicating form.

Now, the elementary body is very stable in the environment, and this is the particle that attaches to cells, particularly in the respiratory tract. In the family chlamydiaCA there are 14 species, and it's very interesting because there's been a lot of research, particularly with molecular methods in the last 15 to 20 years, there's been a lot more research into chlamydia. We know that chlamydia pneumonia and chlamydia rechomenos are human pathogens.

Those are the primary human pathogens, and chlamydia sidicide was previously thought to be the only cause of disease in birds, but we know now that there are many other species that can cause chlamydia. Infection in birds, and two new species have recently been described in the last 10 years or so. That is chlamydia gainsa, which is in poultry, and chlamydia avium, which is in pigeons and insidize birds.

7 other species have been found in birds. We know that the highest prevalence does occur initing birds and in pigeons, but in poultry, we know that chlamydia gainsa is the prevalent species. We also know now that chlamydia infects reptiles.

We, it has been found in snakes, in turtles, in iguanas, and in crocodiles, and these are some of the species listed that have been found in reptiles. Now there's the can with the down at the bottom we see Candida C corrali. These are species that have been described.

They, but they have yet to be cultured, so they're not described or Classified yet as a separate species. So these new species have been found primarily in reptiles and in birds. So we know that chlamydia gainnacea is widespread emerging agent.

With zoonotic potential and backyard poultry. And at first it was thought that this species did not cause disease and poultry. But now we know that the species can cause reduced body weight gains, but, and, and it can certainly infect the workers that work with these poultry.

There was a recent study just in 2018, looking at feral pigeons, and they looked at pigeons in cities in the Netherlands, and what they found was a high percentage of these birds carried chlamydia. So it is something that we have to be aware of, and, know that it's in poultry, it's in pigeons. We don't know what the exact zoonotic potential is from these species, but we do know that it is a potential.

So what is the life cycle of chlamydia? So, as I mentioned before, there's two forms. There's the elementary body form.

And the reticulate body form. So the elementary body is the infectious form. It attaches to the surface of the cell, and here you can see in this diagram that it attaches to the surface.

Then an endocytosis occur occurs and that elementary body enters the cell. And then once it's in the endosome, it, it's sort of reorganises. And it forms into reticular bodies in the endosome.

The reticular bodies then replicate by binary fission. They are reorganised into elementary bodies, and then the path really depends on the species of chlamydia. They can either rupture within the cell, and that will cause cell lysis, and that's what occurs with chlamydia sidicine.

The cells will lice and that's where you have the massive necrosis, particularly in the liver of birds. But in, in human chlamydia chlamydia pneumonia, chlamydia triatus, that is a reverse endocytosis, so it's not as quite as destructive to the cell. Now psittaosis or ornithosis in the US was first described in the 1920s, and this was in an outbreak that occurred in the northeast in about the Washington area, and it was described, it was thought to be in a shipment of parrots that came out of Argentina, out of South America, and into the US.

And it was noted that some people started becoming sick, particularly in the household, and that the people in the household had parrots. And so that's what first described this outbreak and there were about 30 people that died in that outbreak. And that was the beginning actually of the study into chlamydia in, in a laboratory that soon that afterwards became the National Institute of Health in the US.

So in the period from 1988 to 2003, there were 935 cases reported to the CDC. It is a reportable disease in humans in the US. In certain states, it's also reportable disease within, birds and animals.

We do believe that probably it's underreported, because there's only a few cases reported each year in the US. For chlamydia, there's 6 known irriars. This is a chlamydia ya.

All are transmissible to humans. The most common form in parrots is irovar A. The highest risk, of course, is with those people that are in contact with birds, that's poultry workers, people in pet pet bird breeding facilities, pet store workers, and veterinarians.

Now an interesting paper came out just recently in 2017, which was a meta-analysis of studies since 1986. Of chlamydia. And they look back at papers in human medicine as far as a community acquired pneumonia.

And if you look at these graphs, it, it shows you the different testing methods. So you can see in the early part, most of the test methods in humans, similar to in birds were complement fixation. Immunofluorescence and other tests.

And as time goes on, starting in the 2005 or so, really it shifted more toward Serology, particularly in 2010, switched more toward PCR testing. And so that is much more exact methods of identifying the species. The results show that about 1% of incident cases of community acquired pneumonia are caused by Citi.

So that's a pretty high percentage, so, of all pneumonias. This is from a paper in 2007. Where we looked at pet bird breeding facilities in Belgium and what we see is they had a fairly high percentage of birds that tested positive.

And the pet bird breeding facilities, they failed 19% were PCR positive, and 25 of those were culture positive. 20% of facilities had both a PCR and culture positive. 5 others were PCR positive only.

And then they also found 13% of owners were PCR positive. Then they also looked at antimicrobial use in these facilities, and they found that 46% of the facilities had used tetracyclines in the past year. And of these, 18, 8 were 8 were PCR positive and 3 were positive on culture.

So the the result of this study was some question about the role of using antibiotics in these pet bird breeding facilities and if that would result in resistant strains. So far, however, we know that There are no drug resistant strains of chlamydia that have been identified. Now, in pet birds, of course, that's the most common place that we are seeing this.

In the US I have to say it's probably not as prevalent as it was back when we did import a lot of birds, but since that's no longer being done, the stresses are no longer as great on these birds, but we do see it. Most commonly, it's in recently purchased birds, birds in contact with other birds or birds under stress. And the clinical signs are gonna vary with the species.

You're gonna see lethargy, you're gonna see an appetence, diarrhoea, weight loss. Some birds will exhibit neurologic signs, and in Citizen birds, one of the classic signs is this very bright green, lime green urates due to the bilibiliva and the and the urates. Very common in cockatiels and budgerigars, but we, of course, also see it in other species.

Now, we talked about chlamydia in pigeons. This was a recent study in, I think 2017 or 2018, looking at, chlamydia prevalence in wild feral and domestic pigeons in Switzerland, and it was quite interesting. They looked at both feral and captive pigeons.

They also looked at wood pigeons and collared doves. They had about 431 birds in the study. And they found that 73 of the 431 birds tested positive using RTPCR.

They did type the type of chlamydia in these birds. 68 were Citici and 4 were C avian. One bird had a dual infection.

So the results show that the highest infection rates were in feral pigeons and domestic pigeons. So this again points to how prevalent chlamydia infection is in the wild and domestic pigeon population. So what are the control measures?

We want to screen any newly purchased bird, in the pet bird population. Any newly purchased birds should be isolated, or birds that have been recently boarded should be isolated for at least 30 days. You wanna test the birds before boarding?

Practise preventative husbandry. You also need to educate owners about the clinical signs, and you want to discuss risk in backyard poultry and pigeons. So the methods that are used in birds, historically and con and currently, most testing now for chlamydia currently is by PCR.

Other tests are available, the antigenolyzer, the antibody detection, and culture. Very few if any people use culture anymore because it's just labour intensive. The antigenalyzer and antibody detection were used more commonly in the past when we did not have readily available PCR.

And then a clinical case, what we use most commonly are this, the complete blood cell count, the high liver enzyme activity that we see in many of these birds, and also the plasma protein electrophoresis test, which usually shows in acute cases, a very marked increase in Gamma globulins in the plats of protein electrophoresis. So on the CBC you're gonna have usually a very high white cell count. So these are three tools you can use clinically in these birds in addition to the clinical signs.

As far as the human health standpoint, if you have birds that you are suspicious of chlamydia, you wanna make sure you isolate these birds. You use personal protective equipment, which we're very, everyone is now very familiar with using. You wanna institute appropriate therapy, which I'm not gonna really talk about, but of course it's using tetracyclines or doxycycline.

And then if it's required, you want to contact the public health officials according to your government requirements. The next thing I'm gonna talk about is, is methicillin resistant Staph aureus. This is something that is very important in the human health field, and we're becoming to recognise it more frequently in the veterinary field.

So, methicillin resistant Staph aureus is a COA positive staph, It has a penicillin binding protein that's encoded by the mega gene, and usually they exhibit a cytotoxin called Pantin Valentine leucocyin. And that's associated with the virulence of the strain. .

In dogs and cats, we don't see that much staph MRSA. We will see it occasionally, but we more commonly see the staph pseudointermediate. The staph intermediate group doesn't show any evidence of zoonosis.

We also don't, we have not seen any evidence of staph pseudointermedius at this point becoming, zoonotic, but it's something that we need to, to watch. All the nurses are resistant to beta lactam antibiotics as well as cephalosporins. So we don't know the true prevalence of MRSA in animals, and we do know that MRSA, of course, can have a human to human transmission, a human to animal transmission, and we also know there is in rare instances animal to human transmission.

There are several reports reports of MRSA and companion birds with dermatitis. There was a study that was done in 2010, a really nice study. That was published in the American Journal of Research looking at risk factors for infection in dogs and cats.

And what they found was that in, in, in small animals, dogs and cats, they found that at least one course, greater than one course of antimicrobial treatment was associated with an increased odds of getting a MRSA, an odds ratio of 4 to an odds ratio of 17. The other risk factor that was associated with this was more than 1 day of hospitalisation, just like in human medicine, where patients are in the hospital longer, they have a higher risk of contracting MRSA. So an odds ratio of 5 times more likely to develop MRSA with more days in the hospital.

And then with any surgical implant, there was a much, much higher odds ratio of MRSA. There was also some question of whether contact with a human who had been ill or admitted to the hospital increased the risk for MRSA in animals. So things to keep in mind which make common sense, antimicrobial use, increasing hospitalisation, or any surgical implants.

In the same line, we, as we did for, chlamydia, we, we have to use a hospital infection control management of MRSA infections. You want to isolate any animal with a MRSA from other animals in the hospital. You have to use hand hygiene, either soap and water or alcohol-based cleansers.

You want to use personal protective equipment, disinfect the environment, and of course discuss the risk of zoonotic transmission with the owners with any animal that has a MRSA, identified MRSA infection. Similar to MRSA, we need to be aware, as veterinarians of multi-drug resistant organisms, what we call MDROs. These are gram-negative bacteria that have developed resistance to common antibiotics.

These are in the family Enterobacteracia. There's many types of NDROs. There are, the extended spectrum beta lactammase producing these ESPLs, and these, have acquired, this resistance from plasmids.

They carry genes that with resistance to other antibiotics. Then we have the carbapenin resistant bacteria. One example of islepsyella pneumonia, carbapenase producing gram-negative bacteria.

Then you have the imipenin resistant bacteria such as Acinetobacter and Pseudomonas. So these are all bacteria that we have to be increasingly aware of in veterinary medicine. And going forward, I think, we, there'll be more and more attention paid to the role of MDRs, MDRO's in veterinary medicine and how it relates to human medicine.

. And again, more reports coming out. This is just a few examples, pet animals as reservoir of antimicrobial resistant bacteria. Multi-drug resistant salmonella associated with pet rodents.

So, again, we have to be aware of this and, be, vigilant, and when we're, screening these animals for the type of bacterial infections they have. Of course, the classic, concern about this is in farm animals. Where antibiotics are given to animals as a preventative or in treating disease, or they're giving food and water that's been treated with antibiotics to promote growth.

And this selects for antibiotic resistant bacteria. And the resistant bacteria can cause disease or infection in these animals and then basically what happens is you have this transfer into workers or into the soil or directly to the consumer from contaminated products or it can spread to other animals, even wildlife. So the end result can be a resistant disease or infection can develop in humans.

So again, we have to, as veterinarians, just be aware of the potential problem. When you identify MDR MDRO in a, in an animal, you wanna institute contact precautions, you wanna isolate the infected animal. You definitely need to have a judicious use of antibiotics and I know several veterinary schools now have antibiotic stewardship, Or panels that have been instituted to monitor the use of antibiotics in animals in the hospital.

As veterinarians, sometimes we tend to choose the really high-powered antibiotics when A lesser or more common antibiotic would suffice in those instances. And if you do find a multi-drug resistant organism in a, in an animal, in any animal, you certainly need to discuss the findings with the owners. So moving on, we're gonna talk about mycobacter mycobacteriosis a little bit.

So, mycobacterium, if you've dealt with exotic animals at all, you've probably dealt with mycobacterium at some point. And mycobacterium again is one of those organisms. It's very, very complex and there's been many different species and now through molecular epidemiology, we're identifying more and more species and trying to understand the relationships of these organisms.

And they're basically, mycobacterium are grouped into two larger groups. We have the mycobacterium tuberculosis complex called also MTBC or MTC, and these are considered primary pathogens. In humans, we mainly talk about mycobacterium tuberculosis and mycobacterium ariconum.

The animal adapted MTBC organisms are many. We have Mbovis in Carey, which are mainly were are mainly in domestic animals and cattle and in sheep and goat. But these have also been found in wild animals as well.

And then we have many other species that have been identified in several different wild animals that are in this group. All of these are obligate intracellular organisms. We also have the non-tuberculosis mycobacterial disease.

These are opportunistic pathogens, and this comprises the M avium complex which most of us who deal with birds are familiar with the MAM subspecies Avium, but there's other subspecies, MAum hominis, sovaticum, paratuberculosis, and intracellulaire. Then there's other mycobacteria again that we come across in gents, Fortuitum, Kanza, Marinum, and Xenum, Xenopa, and these are, again, they're all, many of these are considered environmental organisms, and they are all protunistic pathogens in animals and in people. So here's a, this was from a really good article if you get a a chance to read this.

This was by Segai and the Vet Clinics in North America and it's a very good article talking about the mycobacterium. Now this was published in 2012 and things have changed a lot since then. But you can see here that what we're looking at, the main ones that we're dealing with are down here in the slow growing book, group, the MAVM and also the MGen events complexes down here.

But we also will see other, in the rapidly growing books in groups in reptiles. So the non-tuberculous mycobacteria are very widespread in the environment. They're primarily transmitted through inhalation or ingestion of water, particulate matter or aerosols that carry these organisms.

And in people, people most at risk are immunosuppressed, humans. For instance, Mavium is very common in older women. With immunosuppression.

There's been really rare evidence of zoonotic disease transmission. However, we don't know for sure. This was an interesting recent study that was published just recently, in that microbiology where The, the authors looked at the prevalence of mycobacterium gents, and we all know that Mgenats is now we recognise is the primary cause of mycobacteriosis in siting and passerine birds.

This study showed a 3% to 91% prevalence on postmortem samples. And they determined that infection can be widespread in aviaries as well in clinically healthy birds. And they also found high rates of co-infection with polyoma virus in some species, and this was mainly in the passerine birds.

And there was some question of whether or not this, organism could be transmissible bird to bird or whether it was mainly, in the environment, these birds were passing in the stool and it's because they were in, in, in aviary situations that it was a high concentration. So in birds, we see, as I said, mainly mycobacterium gents in avium, and the most common presentation is chronic wasting disease. Usually, we will find this is mainly a GI organism.

We find lesions in the intestinal tract. In the liver, it can be in the bone marrow. We've seen it, in other parts of the body as well.

I've seen it in the, cranial to the heart, granulomas. Rarely do we see if ever any lesions in the lungs. Now, that being said, there are, reports and, and I've seen one bird where we did culture a myco or identify mycobacterium tuberculosis and that was in a, in a macaw that was kept in a household where the owner was positive for mycobacterium tuberculosis.

So there can be reverse zoonosis of those types of disease. So you possibly could see lung lesions if you have a group or someone who has mycobacterium. Now, MAvium of or Mgen events is and mycobacterium in general RC and other species.

These are just a few. Reports that are out there, but, it's been Mgen events has been identified in, domestic ferrets and MAVM homoceus. Here's a report of a rabbit that had this infection.

I've seen at least 2 cases of mycobacterium in rabbits. So, it does infect other species, than birds and reptiles. So, the treatment for mycobacteriosis, again, it's, it would be important to try to identify which mycobacterium you're dealing with, because that's gonna have an impact on what your recommendations are.

There's mixed information or mixed, I should say, ideas about whether or not animals should be treated or whether they should be euthanized. If you do choose to treat again, using, if you're dealing with something like Mgen events or MAM, you want to use long-term treatment and the treatment is generally with drugs. That similar drugs as are used in humans.

So again, it's important to identify the species that you're dealing with if you do have a mycobacterium infection, and then, if you have immunosuppressed people, then it is of concern if you're dealing with ming events because we don't know if it is zoonotic or not. But as of yet, there's no reported cases of zoonotic transmission from birds to humans. OK.

Moving on to salmonella. Now, salmonella, I'm just gonna touch on, a little bit because this is, of course, a very well recognised, zoonotic disease. There are thousands of serivars of salmonella.

It's the most common zoonotic disease in people behind Campylobacter. Most human pathogens are subspecies of salmonella enterica enterica, and here we have salmonella typhi, Eiditus, paratyhi, and cholerasuas. Salmonella occasionally isolate from pet birds, but it's most common in poultry, reptiles, and wild birds.

Salmonellosis in humans is reportable and a species or islets are identified through Pulsene, and veterinarians, of course, play a very important role in the public education about the risk of salmonellosis. So we've become more attuned to salmonella recently because of the, at least in the US, the increase in popularity of backyard poultry and with the increased prevalence of backyard poultry, we've also seen an increased incidence of poultry associated salmonella. In a paper that was published, they looked back between 1996 and 2012, they found 45 outbreaks of salmonellosis that were linked to live poultry from male odour hatcheries, .

So, additional risk factors for this are chickens that are brought into the home, cross-contamination of cleaning products or equipment in the kitchens, and any people that have these backyard poultry that treat them as pets and they kiss or they snuggle with the poultry can result in infection. This is from a paper looking at backyard poultry flocks and salmonellosis, as a public health challenge published in 2014, and graphically you can see the number of cases and the number of outbreaks of salmonellosis identified again associated with the increase in the popularity of backyard poultry. So, the CDC has come out with recommendation to prevent transmission of salmonella from contract with live poultry, and these are common, common sense, recommendations.

Any person who touches poultry or objects in the poultry area should wash their hands after touching these. Children less than 5 years of age, elderly people, immunocompromised people should not handle live poultry. Cages and equipment and bowls associated with live poultry should not be cleaned in the kitchen in the home.

All household articles in contact with live poultry should be disinfected, and of course people should not have close personal contact with poultry. Reptiles and salmonella, this is a well-known risk factor, of salmonella infection. Reptiles do serve as a source of infection for other reptiles, as well as mammals in the household.

Where do reptiles get salmonella? Likely, some of them contract infection before they are exported in the pet trade during transport due to stress in those transport during transport or in the pet stores. So these are all high stress environments.

For these animals and they can come down with salmonella and start shedding it. They are usually not clinically show clinical signs. It's been shown that egg-laying reptiles can contaminate the eggs during passage, and there, there is evidence that some salmonella can pass transovarally in snakes.

Antibiotic resistance is common and increasing in prevalence. OK. We're gonna touch a little bit about avian influenza.

Of course, this was a great concern with H5N1. And just to briefly touch on influenza to, to just review, influenza are viruses in the orthomyxoviridae family. They are enveloped, segmented, negative stranded RNA viruses.

There are several types of influenza. Type A influenza is the influenza that we're most commonly talking about. Type A influenzas are subdivided based on their hemoglutinin, which is called H, and the neuramidase in surface proteins, and there are 16 hemoglutinase, glutinin antigens and 9 neuramidase antigen.

And these are arranged all along the surface of the envelope of the virus. Avian influenza has been isolated from more than 100 different avian species and 13 different genuses, . The answerriforms, the charidiforms, gulls, and shore burns are the most important reservoirs for, avian influenza, in the wild bird population.

There are identified low pathogenic strains versus the highly pathogenic strains. All highly pathogenic avian influenza strains are H5 and H7. However, not all H5 and H7 strains are highly pathogenic.

So the H5N1 is currently circulating in Asia and Europe. It's there are reports every day of avian influenza in poultry and in wild birds. So birds shed a high concentration of virus in their faeces.

Pigs are susceptible to both human and avian strains, and this is why pigs are considered the perfect mixing species for these strains. So, The bird flu, of course, was H5N1. The swine flu outbreak was H1N1.

The dog flu is the H3NH strains and H3N2, strains variants. So these are not considered human pathogens or zoonotic pathogens. So what happens is you have a reassortment.

So, avian influenza can be, we know now, directly transmitted from birds to humans, these highly pathogenic H5N1, but it also can adapt. It can be transmitted from birds to pigs and then the virus can. Change in the pigs and go into human population.

But then there also can be the reassortment of the virus that takes on both characteristics of the avian strain, and human strain goes into the pig and then it goes back into the humans and it can be highly infectious. So this is just an example of how these viruses can reassort where the genetic material of the viruses can can go into a cell, take on different characteristics, and then come out as a more virulent strain in humans. So back when we had the H5N1 outbreak, you know, there was a lot of concerns.

Fortunately, that was controlled, during that time and we didn't, didn't turn into the pandemic that we're seeing now with SARS-COVID-2, but that, of course, does not mean in the future that we could be dealing again with a, a very virulent, influenza strain. So that is why constant monitoring is important for these bird flu strains. In pet birds, the zoonotic disease risk is pretty low.

Soiting birds are susceptible to all avian influenza strains, but, really it's rarely isolated. It's no documented reports of parrots that have been naturally infected with H5N1. There was an H5N2 that was reported in Amazon parrots.

However, backyard poultry and waterfowl are at high risk if they have been exposed to amino influenza. West Nile virus is now an endemic virus in the western hemisphere, . Of course, this first came to light in the western hemisphere in in 1999.

This is a Flavivirus. It's an RNA virus and it was first detected simultaneously, . As a cause of death in corvids and, and in zoo birds, and this was correlated with an outbreak, and this was in New York, with an outbreak in of a disease in humans and from that, those, those simultaneous outbreaks, it was determined that this was the same virus, which was West Nile virus.

West Nile virus is endemic, of course, in wild birds. The reservoir host is birds and is transmitted by mosquitoes. What happens, of course, is the mosquitoes can bite a human or an animal.

Horses, of course, are the most susceptible, and, and that's what causes The disease in people. The mosquito species that have been identified as the major vectors of this virus are Culex pipiians, also fasciatus, and tarsalus. In birds, the hosts that are most commonly associated with West Nile virus are robins as well as crows.

Usually the outbreak in birds precedes the outbreak in humans. So, West Nile virus, the natural infection as far as we know in sentencing birds is rare. There's no known zoonotic disease risk from West Nile virus, of course, because it is West Nile is an accidental or or an accidental host in humans.

So it's now endemic, not only in North America, but in South America, and corvids, of course, are very susceptible and it's been detected in over 250 species of corvids. Now, of course, we have to mention SARS-COVID too, because of what we're dealing with now. And there's been a lot of reports or study into the zoonotic potential or what we call reverse zoonosis, zoonosis of SARS COVID-2.

So, We know that animals are susceptible to SARS COVID-2, and the suitability of the animal host, It is important because for productive virus infection. So whether or not the virus is persistent in the animal population is not known. There's a lot of concern, of course, of spillover of the virus from susceptible populations.

It's been reported in, we know, in cats, and dogs, in, large. Feline species, tigers, lions, and other feline species. It's also been reported in primates.

So we know it can infect other species. We know also that at this point in time, it's thought that the infection does come from humans. There's no, the only species that we do know that it's been documented.

Of a reverse osis is in a mink and it is reported in in a fur farm that fur workers became infected with the, the species that or the, the, the, the type of virus that was infecting the mink. So, no reports of COVID-2 in birds or rodents. As I said, it's been reported in other animals.

It's also been reported in there was a recent report from the San Diego Zoo of the virus in, in gorillas in a gorilla troop, and they use treatments that are similar to treatments in humans to treat, one of the silverback males. In all natural infections, it's likely transmission from humans to animals, and there's one report, as I said, of a zoonotic transmission from farming to human. So, what's known is that it's the receptor for SARS-COVV2 is the angiotensin converting enzyme, and that's expressed in cats and ferrets, and this allows attachment of the virus to the host cell.

Compatibility between the virus proteins and the host cell is required for replications. In dogs, there's very, it's been known, it's been studied that there's a very limited replication. There's no replication in pigs or in chickens, so we really don't have to worry as far as we know about birds.

. Of course, group housed animals, just like in people, animals that are in very close contact, have a high risk of spreading the virus to other individuals, and this is why we're seeing these highly susceptible mink farms that, the virus has spread quite readily. There is concern, of course, that the virus will escape from these mink farms and infect animal wild animal population, . Black-footed ferrets, for instance, in the US or wild mink or animals in the, in the mink family.

So there is concern of what can happen with this virus as time goes on. Talk a little bit about cryptococcosis. So cryptococcosis is an encapsulated yeast.

It occurs in a yeast, as a yeast in the host and in the environment. It's worldwide in occurrence. It occurs in soil as well as in some trees, eucalyptus trees, which is Cryptococcus gati.

There's 4 ceratops, there's The, Cryptococcus neoformis, AND, which is we know is zoonotic, and the Cryptococcus gati, we, we don't have any evidence so far with, of zoonosis. We know that Cryptococcus neoformins is not really associated with environmental exposure. .

So Cryptococcus in humans, it's primarily the serotype D, which is the Cryptococcus neoformin's, variation. Cryptococcus gati is less common. It's mainly found in immunocompromised persons and in people, it causes pulmonary lesions and can disseminate to meningitis.

It's the most common central nervous system fungal infection in humans. Pet birds can carry Cryptococcus asymptomatically in the intestinal tract. There's a high prevalence in droppings of wild birds, especially pigeons, and this is where most of the concern is from.

There's rare reports of symptom, asymptomatic infection, as I said, in the intestinal tract of pet birds. So, the zoonotic risk of transmission of cryptococcosis, there are many reports out there. You can go online and look, again, mainly the reports of, of concern about where there's high numbers of pigeons, in, rural or, or in urban areas, especially around, Facilities such as nursing homes or facilities where there's a high number of immunocompromised people.

And this is where we wanna be careful about the use of birds in pet therapy, where there are immunocompromised people. So certainly you want to, wouldn't want to bring a, a pigeon into that type of facility. .

And again, the concentration of pigeons in proximity to hospitals, but that being said, most diseases in humans are acquired from the environment. So, I am just, again, this was a very brief overview of zoonotic disease. I, it was mainly to increase your awareness, perhaps review a few things that you already know about zoonotic disease transmission.

But again, in this, today's environment, I think as veterinarians, we need to, really, heighten our own awareness about zoonotic disease and the potential risks to humans and be aware that this is part of our job as veterinarians to convey these disease risk when we are concerned. So I thank you for your attention and hope you enjoyed this presentation.