A Hitchhiker’s Guide to Bird Flu

Here we go again.
 

There has been a certain amount of news around about an outbreak of an H5N1 influenza. It’s gotten the name “bird flu” because it’s widespread in wild birds, and it’s been running wild through domestic chickens. You may have noticed egg prices. They’re not dying because the bird flu is killing them. Instead the Department of Agriculture is killing them so the bird flu won’t kill them, leading to almost 140 million birds being culled in the last year.

So, failing any other message from this article, let me say:

DON’T PANIC

(Seriously, is there a friendlier font than Comic Sans?)

Of course, not everyone has taken that advice. Governor Gavin Newsom in California has already declared an emergency, and FACT, a humane farming advocacy group, says we need “urgent action to prevent a public health crisis“.

So what is this all about?

This bird flu, or more formally avian flu, is an H5N1 influenza virus. The “H5N1” refers to specific surface proteins that affect how the virus can invade and infect cells. (Grok has a nice summary.) Basically it’s like telling you a person has blue eyes and brown hair — it’s just a description of the virus and how it interacts.
What we do know is that this particular variant of the H5N1 virus subtype — I’m just going to call it H5N1 from now on — primarily infects birds. Now a whole lot of my reporting on Covid in 2020 actually applies here, so I’m going to link you back for the details, but the high points are:

• it’s an influenza virus. It’s the flu.

• it’s reasonably transmissible, with an R₀ of about 2.8 — worse than most flu but similar to the 1918 “Spanish” flu, comparable to Covid, not nearly as transmissible as polio or measles. (You can look back at this article for a more complete description, but basically R₀ is how many people are likely to catch a virus from one subject with the virus.)

This all makes me think about the start of the Covid panic. Back in February 2020, it was pretty clear that Covid would be a lot like a bad flu. Even Dr. Fauci said :

If one assumes that the number of asymptomatic or minimally symptomatic cases is several times as high as the number of reported cases, the case fatality rate may be considerably less than 1%. This suggests that the overall clinical consequences of Covid-19 may ultimately be more akin to those of a severe seasonal influenza (which has a case fatality rate of approximately 0.1%) or a pandemic influenza (similar to those in 1957 and 1968) rather than a disease similar to SARS or MERS, which have had case fatality rates of 9 to 10% and 36%, respectively.2

Now, given the subsequent panic, you might wonder how that could be true. There are a lot of reasons, among them that we couldn’t easily detect asymptomatic or mildly symptomatic cases until pretty late.

I think a lot of the panic came down to a combination of two things: on one hand, a desire not to be proven wrong on the low side — it’s a lot more embarrassing to have people think you were over-optimistic than over-cautious; and on the other hand, it was another example of Trump Trance, where anything that could be made a negative against Trump was emphasized. 

As it worked out, Fauci’s February 2020 prediction was pretty good.

There have been very few human cases of this H5N1, but it has crossed over into dairy cattle, which is causing a little concern. As of this writing (Feb 9 2025) there have been 67 cases in humans, with one human fatality, a man who worked with a flock of chickens who were infected, and who was “over 65” and had “significant co-morbidities.”

In humans, H5N1 can be serious, but it’s hard to get and there’s no evidence of it being transmitted person to person. So in a lot of ways, it really does look a lot like the early days of Covid, when people thought the actual case fatality was going to be in the neighborhood of 4 percent or even 10 percent, not as it turned out more like 1 percent, and less in the developed world.

If you listened to the doomsayers, it could be a civilization-ending catastrophe. What it was, was a really bad cold. For most people, the biggest problem is probably going to be buying eggs — and I’m on a low carb diabetics diet, this is personal for me. But, well …

pic.twitter.com/66RQO4n9wW

— AJ 🇺🇸 (@AjApplegoose) February 8, 2025

By the way, don’t fall for the people trying to claim it’s Trump’s fault — the massive cull of chickens came during the year before  Trump was even in office.

So how should you react now?

• First of all, follow the cover of the Hitchhiker’s Guide. It’s a flu, and it’s not the first time there’s been an H5N1 flu around — in fact it’s really common. If you have chickens keep an eye out for sick ones, and don’t pick up sick or dead wild birds. Call Animal Control, let them take the risk.
• Wash your damn hands.
• If you get sick, stay home — it’s probably a regular flu, but that can kill old and weak people too.
• And if you have to go out while you’re sick, consider, yes, wearing a mask.
  But only if you’re sick. Masks don’t do much of anything to protect you from other sick people, but they do make it less likely that you’ll transmit a bug.

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