Bird flu: It’s time to talk

I’ve been keeping an eye on the H5N1 bird flu situation for months, getting more and more frustrated at this country’s general indifference to its spread. I’m assuming most of my readers are perfectly capable of following the same news I do, so I haven’t bothered talking about it here. But now highly pathogenic avian influenza (HPAI) A (H5N1, ‘bird flu’) has been confirmed in 3 dairy cattle farms in California1—and it’s time to pay attention.

What’s changed?

Why am I talking about this now? After all, it’s already in dairy herds in 13 other states.2 This is different. Here’s why:

California is the largest milk producer in the US. There are a ridiculous number of Californians who, despite all reason to the contrary, persist in consuming raw milk and raw milk products. Regular flu (H1N1, H3N2, and Flu B/Victoria) season is just around the corner.

This combination of factors could change everything.

Why do these changes matter?

Birds spread the virus between themselves via saliva, mucus and faeces. This is probably how it spread to cows—perhaps a sick grackle lands on the rail and poops into a feed trough. The main route of transmission between cows seems to be via their milk—or, rather, via contaminated milking equipment. The cows don’t get dangerously ill. But they shed the virus in their milk for quite a while after their symptoms abate.

Right now, bird flu seems to be transmitted to humans rarely, usually from backyard poultry shedding virus in their saliva, mucous, and faeces. More recently there have also been a handful of cases of dairy workers being infected by cows. Most of these people have mild illness—red eyes and runny noses—or no symptoms at all. None appear to have passed the virus directly to another person. Not too scary, right? But bear in mind these people are merely handling the equipment used to milk the cows. The milk they actually drink is pasteurised, which kills bacteria and viruses.

What would happen if you drank that raw infected milk? I don’t know. But most cats who drink it die quickly, and, in a recent study, six of the six ferrets deliberately infected with H5N1 cultured from a dairy cow died.

Back to all those raw milk, and raw milk product-consuming Californians. They may not die, they may not even become terribly ill, but they will be infected. And with regular flu season almost upon us, the odds of people being infected by both H5N1 and, say, H1N1, H3N2, or Flu B/Victoria—all of which are easily transmissible between people—go way, way up.

When two influenza virus simultaneously occupy the same host, they tend to swap genetic material; mutation will eventually occur—sometimes a dramatic shift. Add to that the fact that the current H5N1 strain is already mutating in several ways associated with viral virulence and host specificity shifts, and the chances of a new, highly transmissible, highly virulent, highly pathogenic strain of flu increase drastically.

What should you do?

Well, don’t panic; we’re not nearly at that point.3 Currently, the odds of any one of us getting bird flu are low. But here are some things I might consider doing:

Pay increased attention to the cats: cats can get bird flu from infected birds. If your cat is a chaser of our feathered friends make sure you either keep them indoors or, if that’s not really an option, make sure that if they catch a bird you take it away from them ASAP. And make sure that you wear gloves and a respirator to do so; that you then obsessively clean everything; and then that you watch the cat for any signs of illness and, if it develops respiratory distress, put on your mask and take it to the vet. (And warn the vet to wear a mask.) Take precautions out in the world: wear a good mask indoors (at least a KN95; an N95 respirator is better4) and in crowds outdoors (as you should be doing anyway). As we also have a lot of specific viral receptors in our eyes, you might want to think about goggles—or at least wearing glasses even if you might normally take them off if you’re not reading.Don’t eat raw milk or raw milk products. Ever. But especially not now. I don’t even eat eggs that aren’t dry-scrambled or hard-boiled, and I’ll be wary of homemade aioli for a while.5Get your flu shot.Think about what what happened during the first two months of Covid and consider laying in a few sensible supplies—emphasis on a few, and sensible. Think in terms of items you’ll absolutely be using soon anyway in the general course of things, like soap and hand sanitiser, and tissues and toilet rolls and disinfectant, and delicious food like butter and chicken that freeze well, and cheese that keeps a while and that you’ll enjoy anytime.6

My hope—however unrealistically optimistic this is in context of the US medical and regulatory bureaucracy’s usual response—is that bodies such as the CDC and USDA and various state governments start taking this seriously: mandating the testing and quarantining of dairy herds (and very possibly beef cattle—but that’s a post for another day); manufacturing the appropriate vaccines and antivirals for both cows and people; and, at the very least, start vaccinating front-line dairy workers (as they very sensibly are already doing in Finland).

Just because a new, deadly pandemic could happen doesn’t mean it will. But just to be very clear, H5N1 avian flu can be and more than occasionally is fatal to humans. The WHO just shared more news about a young woman in Cambodia who died after food prep of an infected chicken—and the virus responsible was a novel reassortant of an older clade of H5N1 and the current clade.7 The UN Food and Agriculture Organisation (FAO) has warned that this new reassortant is now circulating in chickens and ducks. It only takes a few mutations to turn any virus into something that can leap from person to person with the ease of a dancer. It mighut not yet be time to stay awake at night but, as always, it pays to stay informed.

Be sensible. Be safe.

Which I’m guessing means it’s actually present in many others. ︎That we know about. To me it’s very clear that it’s almost everywhere—farmers just aren’t testing because they don’t perceive it to be in their best interests. ︎There again, it’s never a good time to panic. Panic never helped anyone with anything. ︎See https://sph.umd.edu/news/study-shows-n95-masks-near-perfect-blocking-escape-airborne-covid-19 ︎You know you don’t have to use egg in aioli, right? ︎Y’know, unless like me and can’t eat fermented diary and other high-histamine foods. ︎See WHO report: https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON533 ︎