If you live in this one tiny county in California, you might be more likely to die from Sin Nombre Virus than in a car crash.

In the same way that “why does the frozen spinach I want to buy cost much more than it used to?” engages with a vast interconnected web of economies and monetary policies and farmers and supply chains, asking “what's up with this rare disease people sometimes get in my part of the world?” is actually a question about the entire ecosystem, plus how organisms even work.

The reason you have to think about the natural world when you do biosecurity is that the vast majority of human diseases come from animals. What we think of as diseases to humans is a two-dimensional slice of a giant, rotating, obscure shape of many dimensions – a whole world of diseases, little communities of microbes and macrobes interacting and evolving and getting sick and occasionally passing their diseases around between them. Communities of parasites built on communities of hosts, all colliding constantly. This is the large scale of biosecurity. Nothing in infectious disease research makes sense without it. Any question about human health or symptomology or [...]

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Outline:

(01:56 ) Sin Nombre Virus

(03:38 ) The virus without a name

(06:14 ) Mice

(07:34 ) Theres mice and then theres mice

(09:25 ) Different genes, same niche

(12:59 ) Human

(13:02 ) The adventures of a dead-end host

(17:36 ) Do a bunch of people within the regions where it is have indications of asymptomatic or past infections?

(18:01 ) Wait, can we talk about the actual disease?

(19:38 ) Buying time

(21:42 ) Do you need to worry?

(22:51 ) Questions

(22:55 ) Why is the geographic range of hantavirus infection so limited?

(23:26 ) SNV's weird siblings

(27:18 ) But wait, can we check this?

(29:31 ) What makes Andes virus infectious interpersonally, and SNV not?

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First published:

November 14th, 2025

Source:

https://www.lesswrong.com/posts/u4hAr8R82a4HTqkkW/the-rare-deadly-virus-lurking-in-the-southwest-us-and-the

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Narrated by TYPE III AUDIO.

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