Bird Flu is Now Spreading in Dairy Cattle. Are Humans Next?

Why this is a pivotal moment to prevent a pandemic

Photo by Karol Klajar on Unsplash

H5N1, otherwise known as Avian or Bird Flu, has been around for a long time. Mostly, the virus has been passed among wild birds, but there have also been sporadic outbreaks in poultry flocks. Now, the virus has spread to dairy cattle and, in at least two cases, from cattle to people. This has experts in pandemic prevention on high alert. Dairy workers come in close contact with cattle, raising concerns that the virus could mutate in such a way that it can be transmitted not only from animals to people but also from human to human.

Joining me to discuss the risk that H5N1 could become a virus capable of human-to-human transmission, and what can be done to prevent that, is Robyn Alders. She is an honorary professor with the Development Policy Center at the Australian National University and a member of the Lancet Commission on the Prevention of Viral Spillover. We begin by discussing the history of H5N1 before delving into the current outbreak among dairy herds. Alders also explains why addressing the root cause of these outbreaks requires a fundamental shift in how we approach food systems.

The podcast episode is freely available across all podcast listening platforms. The full transcript is immediately available to paying supporters of Global Dispatches

Here is a free excerpt. Full transcript below the fold.

Mark Leon Goldberg: Robyn, thank you so much for chatting with me. Before we discuss this current situation, can you just give us a very brief history on avian influenza?

Robyn Alders: Avian influenza, in terms of scientific virology, is a virus that we’ve known well. But up until the 1990s, we didn’t see outbreaks in flocks of commercial chickens regularly. There would occasionally be a spillover from waterfowl that are known to carry avian influenza virus and often the spillover would be via water sources that would go into the poultry installations. There’d be a diagnosis, and then the animal health authorities would work with the owners to quickly control the disease, stamp it out, and that would be the end of that outbreak.

That was the case when I started in veterinary science in the 1980s. Avian influenza was a rare disease. However, around the 1990s, we started getting protracted outbreaks of avian influenza in flocks. And that was partly because of the density of birds — lots of birds in the one location, and lots of movement of people between those flocks. So, people started talking about vaccination of birds rather than the process of controlling and removing those birds.

In the 1990s there were about 10 billion commercial chickens. Now, we have 26 billion commercial chickens. So, that’s more than a doubling of the population. And they’re all coming out of a very small lineage. So, we have birds that are genetically very similar, raised in large numbers, in high density, and really, from the virus’s perspective, this is pretty ideal. Once you’ve found one bird that’s susceptible, because they’re so similar genetically, many of them are susceptible. So, we’ve made the life of the virus a little easy.

And influenza is a virus that we know causes pandemic — and the “influenza A” virus under which avian influenza falls is the type of virus that has caused all human pandemics to date.

Mark Leon Goldberg: On a scale of 1 to 10, what is your level concern that this situation may mutate into human to human transmission? If the 1917 pandemic is a “10” and COVID-19 is a “5,” where does this outbreak fall in that spectrum?

Robyn Alders: At this point in time, I’m probably getting up to an at least an eight and a nine — and I say that simply because we know that we have a problem with this new sub-lineage that’s turned up in dairy cattle. But we also have a lot of virus that’s circulating, and circulating sometimes in situations where monitoring is less resourced. And so, we don’t know exactly what the situation is. So, I’m concerned that it is highly likely on the probability the more virus you have that, that increases the probability of that one replication that’s going to generate that virus that is going to spread easily between people.

But I also say this is an opportunity because it’s not just about stopping that next virus, that next emergence — this is our chance to emphasize good health. And it’s not just about stopping pandemic in people. It’s about providing the resources and the approach that’s going to lead to good health in animals and good health in our environment.

And that’s what we need for the long-term survival of our species. Because without a healthy environment, without healthy animals, and without healthy plants, we cannot maintain our health. So, it’s a concern — it’s also a fabulous opportunity to really make sure that the systems that are sustaining us are as healthy as they can be.