Veterinary virology is ahead in tackling viruses

Hans Nauwynck is a veterinary virologist. Photo: Atelier 68
Hans Nauwynck is a veterinary virologist. Photo: Atelier 68

The approach to viruses in animal husbandry is better than the approach in human medicine. Human virology can learn a lot from that field, says veterinary virologist, Hans Nauwynck.

Covid-19 has put virology in the spotlight. One virus expert after another appears on television, almost all of them authorities in the field of human viruses. The experience gained in tackling viruses in livestock and pets is hardly discussed, even though there is a lot to be gained from that, says scientist Hans Nauwynck. “The way in which the veterinary world successfully keeps viruses under control is an example for human virology. If the Covid-19 virus had only struck in pig farming, it would probably not have spread as fast as it has now in humans.”

Hans Nauwynck has another message. He is extremely annoyed by the allegation that modern livestock farming is the cause of all pandemics and must therefore be curbed or eliminated. “Celebrities, politicians, writers and journalists just shout. Mostly nonsense. They have no clue what they are talking about. It is true that a virus can circulate in a barn with many animals in it but you can tackle this in that one barn with the necessary bio­security measures. Blaming all the diseases in the world on livestock farming is ridiculous. It is correct that viruses can transfer from animals to humans but that mainly concerns wild animals. Intensive livestock farming, which also falls victim to many virus introductions from the wild, is doing everything it can to ­prevent and control these types of infections.”

Then what about the minks?

Hans Nauwynck: “Remarkable. Minks proved to be excellent hosts for Covid-19. They were infected by humans and not the other way around. The animals were culled because they were a danger to humans due to the formation of new variants. Mink farming fell victim to Covid-19 in humans. This was never properly communicated. From an ethical point of view, it made sense to stop these mink farms”.

What does that complete control consist of?

“Biosecurity in intensive livestock farming has become a completely logical concept. Mind you, this does not include hobby farmers who can cause a lot of problems. Consider, for example, avian influenza. In order to enter a barn on an intensive pig farm, you must go through hygiene locks. Filters on the ventilation block, everything. Livestock farms are highly insulated from the outside world.

“In addition, there is a well-connected identification and registration (I&R) system: every animal, every farm, every transport has a number by which they can be traced. It is completely controlled. Transport of an animal is rare and when it is transported, you must comply with all sorts of rules. It is all set up to try to keep viruses out. You cannot say the same about humans. Only the I&R (passport, tickets) works. The rest (travel, contacts) much less so. In fact, it stops there. Humans travel freely around the world. In this way, we spread viruses all over the world in no time, as Covid-19 has now shown us.”

“With livestock, the virus would never have circulated so quickly. There is no mass travel. If someone wants to catch a flight, they should first check their health and make sure they are virus-free. People who are sick and shedding virus should not fly. Flying is not only an enivronmental but also a sanitary problem. Aimless human travel makes the world one big barn in which a virus has free rein. The question is, who has the courage to address this at the highest levels of public health? Blaming livestock farming is too easy; discussing burning questions in humans is often avoided. After all, animals have no voting rights.”

Are there any other differences in the approach between humans and livestock?

“Take the diagnosis of diseases. As veterinary virologists, we are highly trained to find out what causes a disease. Is it a virus or a bacterium and which one exactly? This is essential to start and improve treatment and prevention. If you go to the doctor with a cold or diarrhoea, you are usually advised to wait it out and come back later if it does not get better. Then you get antibiotics. It is not even determined which germs are involved, a bacterium, a virus, or something else. Nor do they prescribe specific antibiotics.

“That is no longer done with livestock. We have good and even revolutionary diagnostic technology available to really help vets and farmers. These go one step further than a PCR test. For example, we have a new technology in our spin-off PathoSense which is already being used in Belgium, Germany and the Netherlands. With just one test it is possible to see which virus or bacterium is involved and which antibiotic we should use that the bacterium is not resistant to. In addition, the knowledge we have of viral and bacterial diseases is better than in human medicine. We have the advantage of testing directly on the relevant animal species, while in humans it is necessary to work with mice or other animals using an adapted virus. That is a major difference. Plus there is extensive experience with vaccines to control infectious diseases and even eliminate viruses in a targeted manner.”

What else needs to be done?

“Much more money is needed for research. Covid-19 is a coronavirus. There are many more coronaviruses that are even more aggressive, such as the feline infectious peritonitis (FIP) virus that kills up to 5% of cats. We need to look at that so we can find a vaccine for those coronaviruses in time. You would hate to think that a virus that is just as deadly as avian influenza in chickens or African swine fever in pigs could strike humans and for which there is no cure. It would lead to an unimaginable disaster. With African swine fever, you can see how bad it could turn out if you underfund research. We have known for years that the virus was coming. Money has become available but much too late to combat it. Currently, we are trying to empty the ocean with a thimble. African horse fever is also knocking on the door.”

Surely there is a realisation now that money must be put on the table to prevent such disasters.

“Let’s hope so. Otherwise, we have learned nothing. Until now, it has always been very difficult to get money for veterinary viruses. Hopefully, this will change because it is really urgent. We should not wait, because waiting is the wrong attitude. I also don’t understand why the health insurance world does not invest more money in better diagnostics. Currently the diagnosis of most viral and bacterial diseases is not reimbursed. It pays off doubly if you can intervene more quickly and more specifically, as we do in animal husbandry. Letting infectious diseases drag on causes many hospital admissions with expensive costs.

“In intensive livestock farming, you see that continuous efforts are made to increase biosecurity to a very high level. What matters is that we wake up now and start working hard together as human and veterinary virologists. And let’s also realise that as long as there are humans and animals, there will also be zoonoses (animal-to-human) and reverse zoonoses (human-to-animal) at risk of escalating into a pandemic. There is insufficient or misleading discussion about reverse zoonoses. Animals cannot write articles.”

Contributors
Contributors Global Poultry Sector Authors



Beheer