Good afternoon on what is a typically dry Scottish summer day as I record this webinar. It's sobering to think that it's now nearly 20 years since the 2001 UK foot and mouth outbreak that had such devastating and wide-reaching consequences. Today, as we're coming to terms with the global human coronavirus pandemic, it seems appropriate to think about how to reduce the risks of a viral disease plague of the cloven hoofed livestock on which we all depend so much.

Having spent a large part of my career as a veterinary practitioner, I'm going to focus my talk from a clinical perspective. My slides contain a lot more information than I believe I'll be able to cover in the allocated time, but I hope that by having that information there, it might be helpful as a reference. Just to go through some of the sort of learning objectives for this, webinar, I hope that the webinar will help to improve understanding of the impact of foot and mouth around the world.

I hope that it will be helpful in recognising the clinical signs of foot and mouth as a part of the process of disease surveillance. I hope to be able to give a very superficial overview of ancillary diagnostic tests. I hope to give an overview of an improved understanding of the risk of transmission of foot and mouth.

I hope to discuss the concept of effective biosecurity, and then to show an appreciation of the difficulties of foot and mouth control in endemically infected countries such as Uganda, where these lovely pictures of Boran and and coli and crossbred cattle are, are, are, are taken. And finally, I'd like to just make sure that we understand the principles of prevention or eradication of foot and mouth from disease-free countries. So why am I as a veterinary practitioner or, or, or certainly as someone who's spent most of my career as a veterinary practitioner, so interested in foot and mouth disease?

Well, the 2001 outbreak in the UK is still firmly etched in my mind and always will be because the consequences were so utterly, utterly devastating as depicted in this BBC website image at the top. So I want to feel that we're ready for another foot and mouth crisis in Europe, in the UK as and when or should this actually arise. I think part of that means that it's important that we understand how to reduce the risks of transmission of foot and mouth into the whole European neighbourhood to which we belong.

And being able to do that actually requires an understanding of how to reduce the impact of foot and mouth in those endemically affected countries. In particular, from my perspective in those low and middle income countries in which I work and in which I have some experience of, foot and mouth disease and of its control. So foot and mouth is a highly contagious disease.

It's an acute viral disease and it affects cloven hoofed animals. So far as livestock's concerned, that is pigs, cattle, buffalo, sheep and goats. But it also affects about 70 other animal species.

It's characterised by the formation of vesicles and erosions, and classically those are inside the mouth, on the nose, on the teats, or on the feet. As a disease, the mortality is very low indeed in adults' livestock. But when it affects young animals, that is piglets, calves, kids, and lambs, it can actually result in significant high death rates.

And a lot of those deaths are because of an effect on the virus of the virus on the, on the myocardium, so their death rates is death as a result of myocarditis. So foot and mouth can cause high mortality in young animals. The, top, left picture shows, an Indian farmer clutching a calf, which is showing the classic signs of, salivation, but also being such a young calf, it may actually just, end up dying suddenly.

The calf on the right also in India is also extremely sick as a result of of foot and mouth. And the picture of the goat kid is just to portray the importance of this disease in young animals. Why does foot and mouth matter?

Well, it matters first of all because of the direct impacts caused by the disease. And those are reductions in milk and meat production. They are the cost of treatment of animals and they're the direct welfare concerns.

And we only need to look at this Frisian cross cow in Uganda in this top image to see how sick she is, how affected she is, and also to appreciate that her milk production has, has, has fallen right off. It's worth noting at this stage that that clinical impact is much higher in improved cattle such as this one than it is in unimproved native animals. The other important impacts of foot and mouth are those impacts caused by human reaction to the disease.

So that may be the denial of international markets. This was a massive impact during the 2001 outbreak in the UK. It may be knock-on effects on other rural industries, and we also knew that in the 2001 outbreak in the UK there was a massive impact on tourism.

It includes the cost of biosecurity to retain disease freedom or to farm in a situation where the disease is endemic. It includes the costs of eradication, which we know from 2001 were really quite staggering. And it also includes the cost of, indirect animal welfare concerns.

And, and an example of an indirect animal welfare concern is that We think about the US, the US pig industry has enough capacity to last for 2 days in the events of movement restrictions preventing the movement of animals to slaughter. After 2 days, US pig farms will become so overstocked that the welfare implications on those farms will be absolutely massive. And this was something that we also saw in 2001 in our UK food and mouth outbreak.

And then there are social effects, there are social stigmas, etc. Associated with with, with, with, with, with the disease. I showed the picture at the bottom of an animal with foot and mouth being restrained and prepared for examination, not to show the drama of the situation.

I'm afraid that's fairly normal when it comes to working in, in, in, in some of these countries, but actually to show that one of the impacts of having foot and mouth here is that lots of neighbours and friends have to come along to help. To, to, to, to manage these animals. It's incredibly labour intensive.

There's a cost there to the farmer, but there's also a very high risk there of, further spread of the disease. So it's, it's not easy to actually account for all of these factors. I took these pictures during the 2001 outbreak.

I was very fortunate where I, worked as a practitioner, that, our particular practise wasn't affected, but everything around us was affected and the impact was quite, quite devastating. That 2001 outbreak resulted in 6.5 million animals being slaughtered in the UK.

The direct costs were estimated as 3.1 billion, that is 3.1 times 10 to 9 pounds, and the indirect costs were £3.6 billion.

These figures are just staggering when we come to think about the the effect that these figures actually have. Annually, foot and mouth is, estimated to have a global impact in terms of production loss, losses and vaccination costs alone, that is between 6.5 and 21 billion pounds.

I show these pictures here because in, endemically affected countries, one of the biggest, consequences of foot and mouth is actually the loss of draught power. If these animals develop, lesions, in affecting their feet so that they can't actually, walk, then, the, farmers' ability to, to draw income from that, use as draught animals is, is, is lost. I showed this picture here of a, of a camel in India, just to show the loads that these animals, this is actually rice husks that it's towing, but the loads that these animals are, are, are put under, and was advised by some colleagues at Purright that in fact dromedary camels are not susceptible to foot and mouth, but bacter in camels are.

Nevertheless, the image is to make the point about draught power. And Foot and mouth is clinically much less severe in in in endemically infected areas in in naturally indigenous type animals, and most will actually recover with appropriate supportive management. And these two pictures are taken in a part of India where foot and mouth is endemic and where the farmers just know to actually take these animals and to stand them in a, in a pond just to sort of cool down the lesions on their, on, on, on, on, on their feet, and they know that if they do that for about 4 or 5 days, these animals will then get better and that's the end of, of, of, of, of that in terms of the impact on, on these animals.

It's maybe worth pointing out also that when we look at these animals, we see some animals in these images that are in extremely poor body condition, but their poor body condition is not due to foot and mouth. So I'm just trying to put foot and mouth into perspective here as to how it occurs around the world. So, foot and mouth is caused by a small non-enveloped RNA virus, and the fact it's non-enveloped means it's pretty resistant and able to survive in the environment.

It is, however, susceptible to inactivation at either low or high pHs, so we can use a range of disinfectants and they'll be effective. Being an RNA virus, it is subject to frequent spontaneous mutations. And so that gives rise to high levels of genetic diversity, and the high genetic diversity actually allows the emergence and spread of outbreaks to be, tracked.

There are 7 immunologically distinct serotypes, and each serotype has multiple strains. And just cutting ahead a little bit, when we come to thinking about vaccination and cross-protective immunity, there is no cross-protective immunity between the serotypes, and even within some of the strains, the strain variation is such that there's actually no cross protection between the, between the strains within the, the, the, the different serotypes. Around the world, there are parts of the world that are foot and mouth free.

There are parts which are free with vaccination, for example, most of South America. There are a few areas where we see it intermediately and sporadically, and that applies to, Malawi in, in, in SADC, part of, of Africa, where I work quite, quite commonly, and I've certainly been involved with, intermediate intermediate sort of sporadic, foot and mouth outbreaks there. And then there are large parts of Africa and, Southern Asia in which foot and mouth is endemic.

And the world is sort of divided up into disease pools, which are actually determined by which of the, of, of, of, of the different serotypes, and strains, are predominant in, in those, in those areas. The virus enters through the mucosal and lymphoid tissues, of the pharyngeal region. We get initial replication in the lymphoid tissue, followed by viremia, and then secondary replication, in epithelial prediction predilection sites, and that is the coronary band, the interdigital cleft, the tongue, dental pad, teats, and mammary gland, or of its young animals in, in the heart.

The animals then mount an immune response and then they, they, they, they recover. But it's important to note here that the time frame of these events can be very variable. The incubation period can be anything from 1 day to 2 weeks, usually 2 to 6 days.

These, these figures matter when it comes to considering epidemiological tracing. Virus excretion can begin up to 2 days before the appearance of clinical signs and usually ceases 4 to 5 days after the appearance of clinical signs has has actually started, except in the esophageal pharyngeal fluid, where the virus continues to be excreted for a, a longer period of time. And detection of virus doesn't necessarily equate to a high risk for transmission.

So animals can become infected by the inhalation of viral particles from the air. They can become infected through the ingestion of virus particles with food. Rarely, they can become infected through abrasions or through iatrogenic means.

Ruminants, are usually infected by the respiratory root, and it takes very low doses of virus to actually, establish an infection in, in, in, in, in a ruminant. Just a nice picture of Acoly cattle in a, in a foot and mouth, endemic area, just to, to, to illustrate that point. And then below is a picture of a pig to illustrate the point that for respiratory infection, pigs require 80 times more virus than do ruminants.

So that root of infection is rare in pigs, but pigs are actually relatively susceptible to oral infection. And very low doses of virus, can establish oral infections, and that's why swill feeding is such a, high risk, when it comes to pigs, and we know that that had a role to play, an important role to play, in, in, in the, foot and mouth outbreak that we saw in 2001 in, in, in the UK. I'm gonna repeat this, but it's also worth bearing in mind that the pigs can actually release large quantities of virus in their exhaled air.

And so if there are large concentrations of, of, of pigs, they can give rise to plumes of virus. They actually amplify the virus and give rise to, to, to these large plumes, and those plumes can actually spread, depending on geographical barriers, etc. For long distance, and are responsible for, for, for, for, for long distance spread of infection.

Immunity antibody mediated, antibodies are detected from 3 to 5 days after the appearance of clinical signs. That is important when it comes to thinking about epidemiological investigations, and the high, high levels are 2 to 3 days after that. Teeters are detectable for several years after infection in ruminants, but only for a few months in pigs.

The antibodies are directed against both structural and non-structural virus proteins. And I'll explain in a minute that comparing the teeters of non-structural or structural virus protein antibodies can actually be used to differentiate between vaccination and normal infection. And all of these pictures that I'm showing here are either foot and mouth infected animals or animals in foot and mouth endemic areas at the moment.

So, the goat at the top was actually part of a herd of goats which was infected with foot and mouth in Pakistan. Well, I was trying to work with, with worm control in these goats, it didn't have to get in the way of that work. And, at the bottom is is during a foot and mouth outbreak in Uganda.

Some animals become carriers. Ruminants clear the, virus quickly, but pigs don't, although pigs don't become carriers. That's the point I was making about the detection of virus not necessarily being synonymous with the transmission of virus.

. In most animals, the virus will persist up to 28 days in the oropharynx. Cattle, we can get persistence and carriers for up to 3.5 years, goats and sheep for up to 9 months, and in African buffalo, they can remain infected, for at least 5 years, and there can be intermittent virus excretion during those periods, although the role of that in the epidemiology is, is, is unclear.

Small ruminants are generally thought to be silent shedders. They often move for long distances, and, they, the clinical signs of foot and mouth are not necessarily going to be obvious in them. African buffalo are interesting animals because persistence, the virus and infections can actually persist in them.

It has been shown for up to, up to 30 years. But at the moment, there's little evidence of transmission to, to, to, to cattle, but we really don't know. Where the buffalo become important is when it comes to what role are they playing in, in, in tracing of virus strains during epidemiological investigations.

When considering the, risks of transmission, we need to consider the probability of infection and at the same time, the duration or frequency of opportunity for infection. So transmission can be with, by direct contact with infected animals. So these Acoly cattle, there are obviously a lot of direct cattle between, between them, that we see here in this, in, in this top image, or it can be, from long distance airborne spread, and we mentioned before, the role of, large groups of pigs in giving rise to these, viral plumes.

For mites are a much lower risk but nevertheless a risk, and animal products, are only really a high risk in swill-fed pigs or in veal calves that are fed, contaminated, milk. It's really important that we recognise the clinical signs of, foot and mouth, early. The impact of the disease depends on the national disease status, the legislative requirements, and the ability to, to, to respond.

But actually, regardless of the context in which we're talking about that impact, the clinical signs are essentially the same. In, in, in, in, in free countries, we need to be able to identify cases as immediately as possible. And we learned that lesson from the 2001 outbreak, whereas actually by the time that the lesions were first identified in slaughter pigs in the south of England, which had originated from quite a long way away.

The disease was already extremely well established, having started off in the pigs in the north of England and then spread into the sheep which had been moved around the country excessively before we even identified the problem. And that was the problem that the disease was so well established before we even started. So we need to be able to identify cases as quickly as possible.

In countries where disease is endemic or periodic, we also need to recognise the clinical signs in order to inform things like the correct sample collection or to inform the epidemiological tracing that is needed, for the, control of, of, of, of, of the disease. And this picture here is actually a calve or an older calve in, in, in India, and you've got to look twice to see it, but if you look carefully at the picture, you can see the foot lesions, the second trauma, secondary trauma to the, to the foot lesions of, of, of these animals. And I thought that the metaphor here was one that we need to look carefully and particularly in order to identify the the the disease.

The severity of disease depends on the host. In cattle, for example, the severity is much greater in improved breeds than it is in, native breeds where it can be quite mild. There is some variation between virus strains and severity, but it also depends on the infectious dose and on, the level of immunity.

No different in that regard from most of the infectious diseases that we deal with. The initial clinical signs that are seen are often salivation, and I'd like to thank, the, European Commission foot and mouth for, this picture here, which just shows that sal salivation just absolutely spot on as being the first sign that's seen. We see signs of lameness, and we see signs of a drop in milk production.

Milking is often reported as being painful because, the, vesicular lesions actually can, can be on the teats themselves. Animals are pyrexic, depressed, and lethargic, etc. For one or two days just before or coinciding with the first lesions appearing.

There can be abortions, but in many of these endemic countries, we need to remember that there are many, many differential diagnoses for abortion, brucellosis and cattle being the obvious one. Loss of body condition, sudden death in calves, and then as a long-term consequence, we sometimes see chronic mastitis, lameness, and a condition, in, dairy animals, of heat intolerance, that's not fully, understood. The vesicular lesions are on the hard palate, the lips and the tongue between the claws on the teats, and sometimes on the muzzle, on the skin, or, if we look at postmortem, actually on the, on the men, as well.

Going through the lesions of foot and mouth in cattle, the day one lesion is a sort of blanching of the epithelium, followed by the development of fluid-filled vesicles. These aren't that often seen, unless you happen to be there just at the absolute, height of and corresponding with, with, with, with an outbreak. So these are the classic day one lesions.

By day two, the, vesicles, have ruptured and, they are then characterised by being covered by a sort of flaps of raw epithelium. But the edge of the lesion is, is, is really quite clean and at this stage, there's no deposition of, of fibrin. This particular image, the ones, the images that say they're from the EU FMD and Pari, that's where, that's where they're from, but these images show what, what, what, what, what these lesions actually look like.

By day 3, the lesions have started to lose that sharp demarcation around the edge, and they've become slightly brighter red in colour, and we're starting to see, fibrin being deposited around the edges of the, of, of, of the lesion as well. By day 4, and, and, and these are some of my own images, the one on the left is from India, the one on the right is from, is from Uganda, we get, considerable fibrin deposition has occurred, and we're also starting to see some regrowth of the epithelium, which is quite apparent at the periphery of, of, of the lesions. By day 7 we've got a fairly extensive scar tissue formation and healing.

There's some still some fibrin deposition present, but it's starting to look like a good healing lesion. And by day 10, all we're really seeing is a bit of scarring and a bit of indentation at the site of the lesion with some fibrous tissue, and, on the tongue here we've got some, loss of the, of, of, of the papillae. These lesions are, yes, there's, there's, there's a little bit of, there can be questions asked about, what is a day 2 versus a day 3 lesion.

Sometimes without taking a really careful look, it can be quite tricky to differentiate between epithelium and, and, and, and fibrin, but with a little bit of practise that becomes, good. It is actually possible to to, to, to, to, to, to date the clinical signs really accurately based on these lesion, definitions. Ageing of foot lesions, as in these, Indian foot lesions here, can be, much less accurate, because of, the impact of, secondary infection and trauma, as is quite apparent when we look at these, images that, that, that we've got to see here.

There are a number of differential diagnoses, and I'm not gonna go through all these differential diagnoses. But I would argue that most of those differential diagnoses can be eliminated through a thorough, hard level clinical investigation. I won't pretend that during the 2001 outbreak, I gave myself a few frights when identifying mucosal disease in, in, in cattle, and I had to ask myself were these cases of mucosal disease, fortunately something that we're not seeing anymore anyway in this area.

But were these cases of mucosal disease, actually, foot and mouth cases? And a colleague, a very senior and well respected colleague, Phil Scott, reminded me, very quickly at the time, if it's mucosal disease, it'll just be affecting one animal or maybe one or two animals. If it's foot and mouth, there will be other things going on in that group of animals.

It's inconceivable that we, there won't be. So we really ought to be able to rule out these differential diagnoses based on, just doing a thorough, hard-level clinical, examination. In pigs, foot and mouth can cause extremely severe disease.

We can have recumbency, reluctance to walk, severe pyrexia, severe lameness, and severe loss of, body condition. The main site of the lesions, is on the coronary band, and between the, the, the, the, the, the claws and sometimes extending up the leg. Lesions are also sometimes seen on the teats and less frequently, in, in the mouth, certainly compared to, to, to cattle.

The main lesions in pigs are those affecting their, their, their feet. And again, there are a number of differential diagnoses, in particular vesicular stomatitis, swine vesicular disease in the USA Seneca virus valley virus, and, vesicular exanthema. Some of these may be not so easy to differentiate from foot and mouth, given that they are sort of similar aetiology, viral diseases.

But those are the, the differentials in, in, in, in, in pigs. Small ruminants are a problem. I don't mean that in, in general terms.

Small ruminants are incredibly important in general terms, but, from a foot and mouth perspective, they're a problem because the disease very often goes unnoticed. And going unnoticed, that results in silent shedding and spread. Where we do see clinical signs, as was the case in this particular Pakistani outbreak, the main signs are lameness and mortality in young lambs or, or kids.

We also see loss of body condition. To what extent the loss of body condition in some of these Pakistani goats was due to foot and mouth. To what extent it was due to other factors such as hemonus and lack of good nutrition, I don't know.

And also, this particular, keeper was complaining about, extremely high levels of abortion, in this herd of goats. Where we do see vesicular lesions, they're on the coronary band, on the teats, and in the mouth. But the main site is on the coronary band.

And just some EUFND images just to show the lesions. Yes, when you've got obvious lesions, they're nice and obvious, but looking at these lesions on the coronary band, for example, you've got to look really carefully. You've got to lift the hair back in order to actually see those those lesions.

There's a lot of differential diagnoses there, but actually with a good clinical examination, it ought to be possible at least not to misdiagnose foot and mouth as being one of these other differential diagnoses. I understand that certainly locally to, to, to where I was based down just here in southeastern Scotland during the 2001 outbreak, that there were a lot of flocks of sheep that were unnecessary slaughtered, as a result of having, or, and. I think that's something that we need to be extremely mindful of.

So what about ancillary diagnostic tests? Well, we have to consider whether we want tests for antigen detection or tests for antibody detection. We need to look at the time frame of the disease to work out what tests are likely to be informative based on the stage of the disease that we're looking at.

When it comes to tests for, antigen, the best test of all or the best sample of all to use for antigen is vesicular fluid from an unruptured vesicle that can be collected just by, fine needle, aspiration. But it is really difficult and it is, you know, on, on the one hand, it's unlikely to actually find those lesions, but they have a tendency to burst just as they're being handled, so it's really difficult to get, but it's the best material, for, any investigation. Tags of epithelium from lesions up to, day 3, can be very useful for antigen detection.

Oral pharyngeal and nasal swabs, they're getting to be less useful, but they can give positive results, saliva less useful as, as, as well. And sometimes pick it up in EDTA blood if it's a postmortem on a young animal and looking at the heart, heart muscle, but, . One way of improving the probability of getting virus from some later infections is to actually use a a sort of scraping cup device that goes on the end of a prob and is to actually sort of scrape material from the back of the of, of, of, of, of the pharynx.

For antibody detection, we need clotted whole blood. When it's for virus detection, we need to think about, transport media, we'd need to think about contacting the laboratories, suitable packaging, etc. Etc.

The virus itself, it can be isolated, by, tissue culture, by cell culture, that usually takes about 4 days. It can be detected by an antigen, elizer, which can give quite a quick, result within maybe 4 hours of getting to the lab to the lab. We can use, a, reverse transcriptase, PCR method.

It does require having, it, it, it doesn't require having live, live, virus, which is, for the LIA obviously is, is, is, is a, and, and the cell culture is, is, is, is needed. So it can be very sensitive, and, we can get results in, in 4 to 5 hours. Sometimes what happens now in, in, in epidemiological studies is that the, whole virus genome, which may have been, recovered by that PCR or, or from the, the cell culture, will be, will be sequenced.

Well, it needs PCR to sequence it anyway, but the whole virus genome will be, will be sequenced. There are some excellent penside lateral flow devices, which are based on the antigen Eliza method. They're highly specific.

They have a sensitivity that equals the lab, Eliza, and they're panserotype, and they can give a penide diagnostic within, diagnosis within 10 to 30 minutes. And these pictures show the use of that, penide test. First of all, taking a bit of epithelium.

Secondly, mashing it up in some PBS and then literally adding it to the well of the penide test. And, within a few minutes of taking that picture, there's going to be a couple of nice bands will appear, or did appear, across the, across the, the, the, the test. These tests are still not acceptable by OIE in terms of, of global management of the disease, but they are incredibly useful, certainly when working in, endemically infected countries and in epidemiological investigations there.

When it comes to tests for, antibodies, there are antibodies against both structural proteins, which are found in the viral capsid and against non-structural proteins which are involved in virus, replication. The, process of vaccine production actually removes the non-structural proteins. So if we compare the structural and non structural antibody titers, we can actually differentiate between natural infection and and vaccination.

And that can be quite useful in countries that are maybe moving from a sort of, dealing with foot and mouth, up to the sort of next tier in the, in, in, in, in, in the, foot and mouth, status that, that, that, that, that we've got. And here we've just got some, lovely, and coli cattle in, in, in, in, in Uganda in a foot and mouth endemic, so. One of the things that always put me off foot and mouth, and getting too involved with it, .

Until I started working with it in, in low and middle income countries or or, or, or working in association with it in low and middle income countries, was the fact that actually in the UK here, the moment that initial diagnosis is, is made, it, it's taken out of our hands because foot and mouth comes under legislative framework. Works. And that is absolutely correct.

It's absolutely necessary that, that, that, that has to be, has to be the case. But we need to be aware of the fact this is a notifiable disease and it operates within an international, legislative, framework, and that just has to be the, the situation. Foot and mouth vaccination is something that started being talked about quite a lot during the 2001 outbreak here, and it is something that is really important in these low middle income countries that I, that, that, that, that I now do have projects in and where foot and mouth tends to get in, in the way.

These are killed vaccines. They've got high levels of adjuvant to stimulate immune responses. They have to be matched to serotypes and strains.

There are huge differences around the world in the quality of the vaccines that are available, and they really do need to be good quality vaccines, especially when used for emergency, vaccination programmes, for example, in countries that are trying to, eradicate the, the, the disease. They do protect against clinical signs. They do reduce the likelihood of infection if the animals are exposed, and they will reduce virus shedding if an animal is infected.

So they will be useful in the control of clinical outbreaks, and they will be useful in reducing the impact of the, of, of, of, of the disease. But there's a lot of thought has to go into vaccination strategies, when to do them, which animals, and where, how to use them, whether it's as a routine prophylactic tool, as I've seen them used, it's not particularly good effect in, in Pakistan and, and, and in, in. In India, and also, in, in, in parts of, Africa as, as, as well, or whether they're to be used as part of an emergency response, which may or may not happen should the UK ever experience another foot and mouth disease.

And they're important as part of exit strategies, as countries are eradicating the, the, the, the disease. And proof of freedom from the disease then requires that comparison of structural and non-structural protein antibody ttos to determine whether we're dealing with natural infection or vaccination. So I mentioned exit strategies, there's a number of different exit strategies, but the rules as to how long it then takes before an a a country, regains its freedom are set in stone by the OIE.

Biosecurity is really important. I couldn't help during the 2001 outbreak in the UK wonder as to how effective or otherwise these mats of straw soaked in disinfectant were as we drove on and off farms, and I, I have a funny feeling they weren't particularly effective, effective, but they served as a very important reminder of the need for biosecurity in, in, in other ways when moving between farms. There are 3 principles of biosecurity.

One is physical segregation. The next is cleaning to remove contamination, and then the next is disinfectant, disinfection to kill remaining viruses. Disinfection, by the way, only works if there's thorough cleaning first, as shown in this picture, just, just down, down below.

And, the standard disinfectants used for foot and mouth are either 0.2% citric acid or 1% vercon. Moving on now to epidemiologically investigations of foot and mouth.

The inputs for foot and mouth epidemiology are our understanding of virus incubation emissions and survival, understanding of virus transmission and the probabilities of that happening, understanding of what constitutes an epidemiological unit, and understanding of the concept of distance, time, and modelling. We need to take that information that I've sort of skirted over already as to when is the incubation period versus when is the appearance of clinical signs. How can we take those ageing of clinical signs to then work out when the animals became infected and for how long those animals will be infected, and we need to consider those factors in that epidemiological outbreak.

Thinking about risks of, of, of transmission and probability of, of, of transmission, I quite like my picture that I took in Uganda of, of these cattle being loaded onto a the back of a lorry, and they will be travelling probably quite long distances on, on, on the back of that lorry. Who knows whether they're going to go to an abattoir or if they do go to an abattoir, whether that's where they'll stay, and, and where they're going to end up, the obvious risks are there. To a lesser risk, but it's still a risk.

We've got the milk tanker in the background. I couldn't believe my luck when I saw the, the two of them together, just in, in, in, in the, in the one scene and, and had to stop and take a photograph. We've got the milk, milk tanker in the background.

Is that vehicle carrying. The the viruses as fomites, etc. The people that are on that vehicle, it's going from a lot of farms, so we've got a lot of opportunity there for, for, for spread of, of, of, of, of virus, albeit the amount of virus is relatively low compared to what's on the back of the lorry in the foreground.

And then my picture on the right is of transhumans sheep production in India. This is a flock of about 1000 sheep and a few goats as, as, as, as well. And these cover vast distances.

They do come in contact with other ruminants on the way, and I think the risk of transmission of Foot and mouth is obvious when we look at these animals. In fact, I took this picture more because of concerns about the risk of transmission of PPR at this particular instance than foot and mouth, but there, there are, well transhumans is a fantastic system, and it would be a travesty if we were to lose it as a system. It, it, it, it does come with, disease transmission risks.

I took these pictures just while out on my daily walk with the, with the dog just on the Pentland Hills and the cattle, the, the, Angus cattle belong to the main farm they've been walking through. The Highland cattle belong to a different farm altogether, and here we've got them sniffing at each other over the, over the fence. There's an obvious risk of transmission, there.

And then also, here we've got shorn sheep trying to jump the fence, trying to jump all these very biosecure boundaries that we've got, and, and, and to join with, with, with the, unshorn sheep. Actually, to be honest, the shorn sheep had come from the, where the unshorn sheep are, but they'd escaped in the past and now they were trying to break back in again. But I think we can see the, the, the, the risks.

Biosecurity to improve these risks. It's obvious what we can do to improve the, the biosecurity risk with the Highland and the, and the Angus cattle, for example. They don't eliminate risk, but they can reduce the transmission probability by many, many orders of magnitude.

So biosecurity is really important. I mentioned epidemiological units. This basically just refers to groups of animals that are kept together within a defined, area, with a defined relationship with each other and with similar likelihoods of exposure.

So these sheep and cattle just in these fields side by side, are clearly one epidemiological unit. Clearly all the nice buffalo here in this Pakistani image are one epidemiological unit, but so are the cattle that we can see on the same farm behind them, and actually just behind where I was standing was also a large herd of goats which were also part of that epidemiological unit that we were looking for. We need to consider, effects of, things that are going to, affect that, spread of disease.

This is actually a, a flooded, boggy sort of area, which actually forms a perimeter to an area in Uganda which, has got, a foot and mouth, problem. That is a really good barrier to prevent the, the, the, the, the spread of infection and, and was an important part of this, epidemiological, investigation. Likewise, when it comes to wind-borne spread, OK, this one pig and a few piglets are not going to be giving off plumes of foot and mouth, but there may be lots of other pigs that are.

But in this particular instance, this is in Malawi, which is only a sporadically affected country, but it's a very mountainous country. These mountains actually will get in the way of and will help to prevent and reduce the impact of airborne spread of, of, of, of the disease. Most of the foot and mouth, investigation epidemiology is no different from what we do, when we're doing health planning as practitioners on UK farms.

I suppose the only difference is that in the investigation of foot and mouth there is access to the sort of data that we don't generally get access for, to, to in those situations. And when we take all of the information that we've gathered and we can put it all together, we can start to generate things like these, these maps, etc. Which will help us to, to, to, to, to, to, to, to, to follow the spread of disease.

We need to, when we're doing that, we need to prioritise. The, the, the, the risks, we need to look at, for example, pigs as airborne, shared airborne spreaders, as sheep as silent spreaders, where the role of personnel comes, what contact they have with animals, the role of vehicles, equipment, and then I've got another picture here just of cattle being moved around the country. So for the last maybe 10 minutes, I just want to talk about some experiences of foot and mouth in Uganda.

And the first thing I want to talk about is an in an epidemiological investigation. This investigation pertains to, community raised cattle in, different, villages along a 5 mile track. I must admit, driving along it, it felt more like a 30 mile track.

But, this is a 5 mile track, from the, from the main road, which is also a track, and, there was a foot and mouth outbreak going on along this track. There's very close contact between all of the animals. There's a suspicion that the number of animals, affected could have been much more than, those that were presented with maybe about 1000 animals at risk.

First case had been reported on the 8th of November 2019, but The first infection could have been, and, and from that, sorry, the first infection could have been between October 19th and November 4th. So we took the date of the first infection and then we looked at when clinical signs would arise, when the disease could have come in, and we worked that out. These are some of the lesions, just to point out that, this was in conjunction with the EUFMD and they do not condone not wearing gloves, by anyone who's, who's, who's working, there, and also the, the watch or whatever it is around the wrist shouldn't be, shouldn't be being, shown, but it's a real situation and that is quite fair enough.

So, we, these are just some examples of the, of the lesions in some of the cattle. One thing I would point out is that, these lesions are really obvious. It's not something that we're going to miss.

There were some, there were also some with tee lesions. I haven't got pictures of them there. We could look at the lesions, we can age the lesions.

We can collect other clinical data, and we could see that in this group of animals, the oldest lesions were about 10 days old, and we can use that to sort of track back to where the disease may have come from. And our Ugandan colleagues were able to track back where this disease would have originated from, and they were able to come up with with this sort of map tracking back to where it was. Then we need to consider tracing forward.

We need to, consider, from those signs being 10 days old, we need to then count back 10 days, and we then need to think about what have the contacts been, that have been occurring at that sort of time and what have the contacts been subsequently from, from that as well. And we need to look at and rank the, the risks in this area. And, the main risks that we identified were that there are free roaming, free-ranging goats everywhere.

And actually the goats are just there as as ATMs. They're just there as cash reserves and in this particular community, which is very much a cattle-focused community, there wasn't a lot of attention paid to, to, to, to, to the, to the goats, and they are certainly a major source of, of, of, spread of, of foot and mouth. There are also antelope in there, people are quite quick to blame the antelope, just what the role of the antelope is, is, is, is unknown.

The fences are pretty porous. The animals have to come to communal water sources, which is, an issue and a problem in, in, in many parts of the world. The farm needed to bring in, neighbors' help, when dealing with the problem.

There is milk collection because these are, are dairy animals, some of these animals, and also there are a lot of charcoal burners, moving around in the area. There's some vehicle traffic along the, the, the, the, the track as well. The main barrier transmission was that swamp at the edge of the village that I showed you.

So what can we do in these situations where we can reinforce the fencing, but if we look here at the fencing being reinforced in the top image, mm, it's really, it's impossible to keep the goats out. Let's, let's, let's be quite honest. We can put in place, not having new visitors, but we have to have visitors onto these farms and people can't survive without that.

Yes, the risk is actually reduced by these being indigenous cattle, and actually, the thing that struck me was that the farmers weren't that fussed about the disease at all. They didn't really recognise these animals as being particularly, sick. This was actually the 3rd outbreak since 2017, and these animals probably had quite a high level of, of, of, of immunity.

Surveillance is necessary. It is necessary to undergo symptomatic treatments, but what's really needed is, is, is, is vaccination. But in this particular area, there are issues with availability of of quality vaccines.

Well, availability of vaccines, full stop. You can see in the bottom image the issue that we've got with a, a communal water source as well, bringing, different groups of animals together in the spread of disease. Now I want to talk about, a much bigger commercial farm, and what does foot and mouth, mean in, with, with reference to that again in, in, in Uganda.

This is a, a, a farm, just referring to it as our, our farm, just the initials for, for the farm. And it's a 64 square mile, farm. It's, made up of marginal grazing, as we can see, in, in, in the top image.

Access to feed is, limited. Actually the main limiting thing is the need to walk for long distances to find water, in, in, in the dry season. Farms split into four sections.

Section 1 and 2 are farmed as one unit, with about 1500 aoli, which are the nice long horned cattle, Barran cattle, which are the ones in the, foreground in, in these images, and also Sahial and crossbred cattle. 3 and 4 are tenanted farms. I would farmed with similar numbers of cattle, and there are also small numbers of farmed, goats and a few dairy cattle on Section 1, but there are also, sort of these free-ranging goats, on, in particular on, on sections 3 and 4.

Just to show some of the dairy cattle, and then to show some of the goats. And this is the main road that runs right down through the middle of the, of, of, of, of the farm, and we can see these are farmed goats, these ones, but we can see these farmed goats actually, and you can't keep them in, and, and, and, and, and so we need to consider where the risks are here. When looking at the risks, here we've got a sort of risk map that we came up with of, of, of, of, of the, of, of the farm.

We were working up in section 1 and section, and, and, and, and section 2. We've got the risks from the farmed goats, we've got the risks from the free-ranging goats. There are antelope and buffalo because there's a wildlife reserve on one, boundary of, of, of the farm.

There's no fences between the sections on the farm, so there's nothing to keep the owned cattle separate from the tenanted cattle, for, for, for, for, for example. The perimeter fences are, porous, and, along one side there's a massive, truly enormous sugar beet, estate. And actually, that in itself, would have displaced a lot of, smallholder livestock keepers who then sort of trespass and, find their way onto the, on, on, onto the farm here because they've got nowhere else to, to, to, to, to go.

And then there's the risks of common watering areas. There's also risks of human and fomites. And spread through people living on, on, on, on the ranch, trespassers and vehicles using this road that goes right down through the middle of the, of, of, of, of the farm with no real effective biosecurity controls.

I'm not actually convinced that there is such a thing as effective biosecurity control for, for that, but that's another issue. Here's the, entrance, or rather the exit to, to, to the farm exiting onto, onto the road. You can see there is actually a disinfection, dip for, for vehicles.

It's bone dry, it hasn't had anything in it for a long time. Personally, I'm not convinced that it's, that it makes any difference because I think we, when ranking the, the, the, the risks, the Normity of, of, of, of the, infection from, animals, is, is, is, is so great compared to the, risk of infection coming in on vehicles. But interestingly, when we visited there, I was with some American colleagues and they were utterly focused on, on the importance of this tyre disinfection, dip.

There's a risk there with, milk collection, just, milk churn just to, illustrate that, point. Talked about the sugar beet plantation, the, the, the, the, the fact that yes, you'd think that gives a nice biosecure boundary, but it displaces people, and this is a, a, a, a sort of, small herd of smallholder cattle and, and goats, and there's probably some sheep in there as well. And this is right on the, roadside, boundary to, to, to, to this farm, and these animals will find their way onto that, on, onto that farm.

What's the impact to this large farm? Well, they had no good records. Yes, they reported sick animals, ill thrift, abortions and deaths, and yes, they, understood that they, you know, there's a welfare, issue.

Actually, there are numerous other reasons, in the area for those, for, for, for those diseases, and it's very difficult to know how many of those in this type of farm, you know, beef cattle farm, to, to attribute to, to, to foot and mouth, and how many are actually attributable to, nutrition, to other infectious diseases, tick-borne diseases in particular, hemonosis, etc. Etc. The biggest impact here was the economic, social, and farm management impacts due to an extended government imposed quarantine, which had been on the go since 2017, which meant that they couldn't sell breeding animals because these, those are pretty smart animals that I was showing you in the, in the earlier picture.

They are a lot of them are there. As, as, as for, for breeding, for their genetics, etc. They couldn't sell bull services for, for, for, for AI.

They had limited opportunities to move animals off the farm for, for, for slaughter, so they ended up with more cattle on the farm that they should have. Then they have problems with access to water, etc. And the number of cattle that can be fed and etc.

This is all compounded by the fact that biosecurity is totally impractical here, and, vaccines have not been available in the country, certainly for the last two years, which increases the risks of recursion of infection. What can they do to, to, to mitigate against foot and mouth in these situations? Well, they can look at the risk of foot and mouth spread from people in homites.

I think we need to put this in, in, in context, although that's a, that's a personal view, rather than necessarily an official view. We need to look at decreasing the spread between animal contacts. I don't know how we do that.

What we really need to do is to, to, to, to resume vaccination as a preventive tool when it becomes available. And when that happens, it has to be all cattle and all goats on the farm. It's really important that the strain selection of that vaccine is correct.

It's really important that the vaccine is of good quality. The cold chain becomes really important, and it also has to fit in with, district and national level, strategies. Above all, what that farm can do is to actually, look at herd health management for all of the other husbandry and nutritional and infectious disease threats that they can do something about.

And the day I visited here, here, here were cattle being being dipped for, for, for ticks and for tick tick disease control, in particular East Coast fever. So, what have I learned from my experiences of foot and mouth, in Uganda from these investigations that I've shown, but also from the foot and mouth that I've seen and experienced in India and Pakistan and the consequences of in, in, in, in Malawi. The first thing is that the process of investigation of foot and mouth is no different from any farm level veterinary investigation of animal health and production challenges.

The only difference is that in foot and mouth, it becomes statutory and also there is availability to those doing the investigation of much greater data sets than we as veterinary practitioners can ever imagine. I think, veterinary practitioners should not dread missing or misdiagnosing foot and mouth when it occurs in cattle. The lesions really are clear cut, and it should not be possible with a thorough approach to miss.

These lesions or to, to, to, to misdiagnose them. Or at least if they are missed or diagnosed or or misdiagnosed, then there will be very clear mitigating circumstances for, for that. So we shouldn't be frightened of foot and mouth in, in, in, in, in that respect.

Investigation of foot and mouth involves access to records and data recording, but certainly my experiences are that the outcomes of the investigation are only as good as the inputs in those records. In indigenous cattle, statutory control measures for foot and mouth are potentially, more socially and economically damaging than the disease itself. Having that focus on foot and mouth overlooks other important disease challenges to cattle in these areas.

And when we look at foot and mouth in these endemically infected areas, we need to consider it in, the context of the whole farming system. And just, while we're here, just these are some of these beautiful Barran cattle on, on this farm. This is a favourite image, this shows large numbers of pigs on the move, and to me it, it, it, it depicts, everything, about the, the spread of foot and mouth that we should be worried about.

To summarise, foot and mouth is highly contagious. Infection requires a very low dose, while the virus is produced in large quantities by infected animals, these pigs being that, being, being these both these multipliers and what can give rise to the long distance spread, etc. As well as local spread when we see them on a lorry like that.

The virus is present in all excretions and secretions from these infected animals. The morbidity rate is high, the mortality rate is low, but that in itself makes the foot and mouth disease more infectious because infected animals remain alive to infect others. And the virus can persist in the environment, so it's a bad virus to be dealing with.

It has economic, animal welfare and social impacts in endemically infected regions, but foot and mouth is utterly devastating when it occurs in a disease-free country such as the UK. And there is a really important role of livestock producers and veterinary practitioners in the UK, which is to ensure effective biosecurity. OK, that needs to be at national level, but it also needs to be at farm and personnel levels, and also in surveillance and immediate response on suspicion of disease.

And that's the main reason why I agreed to give this webinar, is to get that message about the important role of practitioners in the UK. So I want to share my experience of the disease in order to get across that important critical message about the role of veterinary practitioners in the UK when it comes to. Finally, I'd like to acknowledge, Jenny Maude and Keith Sumption from the European Commission for the Control of foot and muth Disease, which is, associated with, the, FAO.

I'd like to acknowledge David Peyton. David and Keith were both in my class at, at, at that school, many, many, years, years ago. And, David, was, from Pur Bright Institute and, has, helped me, enormously in, in my understanding of, of foot and mouth, and also check through these slides for me.

I'd like to thank all the people who I met when on the EU foot and mouth disease, training programme that I attended in, in, in, in Uganda. I'd like to thank my colleague Andy Hopker, who has, been involved with some of these foot and mouth cases that we Shown in India and my colleague Pakistani veterinary practitioner, colleague who's a PhD I, I helped to supervise, who took me to see these, goats with foot and mouth, that we showed the pictures of in, in, in Pakistan. So thank you very much.