Thread by @1goodtern

People are just not going to be able to get their heads round the slow incubation period of hantavirus.

On reflection, thousands of people have probably already been exposed, and those thousands could expose tens, even hundreds, of thousands more.

The sheer time scale is almost impossible to grasp when placed in the context of people engaged in the kind of fast international travel involved with a cruise ship.

You might think that's ridiculous because a cruise ship is slow and contained, but it's not the cruise ship so much as the interwoven pattern of flights people take to *get to and from* the cruise ship.

A busy international traveler on their way home from a cruise ship could easily cross paths with 5,000 people in a day, more if you consider genuine airborne spread.

You don't need a high rate of transmission when you sustain that rate of encounters.

Do I think this is going to turn into a pandemic?

The weird thing is that we won't know for another three months minimum.

We could get just five more new cases in the next month (we'll probably see more than that, is my guess) , then suddenly a hundred more.

Then only a few for a little while, then two hundred more.

This is a strange situation.

And we shouldn't assume that Andes will behave the same as it has done in the past.

Not because of the virus, but because of the people.

Covid infections have interfered with some of the very systems of the body that control infections.

People may be more susceptible now, and more transmissive now.

I've been warning about this for five years now.

Secondary infections are one of Covid's ongoing curses.

Here in England *three times as many people* are dying from infections as were seven years ago, as a proportion of all deaths, based on the 'main underlying cause of death' data from the ONS.

The pathogens haven't changed, but the bodies have.

Covid affects the vascular endothelium (the linings of blood vessels), the system that Andes hantavirus targets.

Covid and Andes both trigger

endothelial dysfunction
capillary leak
immune overactivation
coagulation abnormalities
vascular inflammation

Andes is no longer landing on unprepared ground.

Covid bodies may be more receptive.

If someone already has vascular dysfunction, chronic inflammation, impaired interferon responses, microvascular injury, metabolic disease, or lingering post-viral abnormalities, they may have less physiological reserve when another endothelial-targeting virus arrives.

Things are not as they were.

Add into that mix that a sector of the population now believe it's their duty to spread whatever illness they have, and we may be in a worse position than I had previously considered.

I think I was wrong to say outright that this won't spread extremely widely.
The chance of a very large spread of Andes is above zero.

I still don't think the chances are high, but with every stupid day that passes, I get more concerned.

And, like I said, we're not going to be completely sure about the level of danger for three to six months.

Which is why we need to defib the precautionary principle some time soon.

Any time now would be good.