Marc Johnson Profile picture
Jun 4, 2023 15 tweets 4 min read Read on X
Ohio cryptic lineage update.

We’ve made no progress identifying the individual, but we have learned a few things.
1/ Image
First, the signal is almost always present in the Columbus Southerly sewershed, but not always at Washington Court House. I assume this means the person lives in Columbus and travels to WCH, presumably for work.
2/ Image
Second, the signal is increasing with time. Washington Court House had its highest SARS-CoV-2 wastewater levels ever in May, and the most recent sequencing indicates that this is entirely the cryptic lineage.
3/ Image
Third, I’ve tried to calculate how much viral material this person is shedding. (Multiply the cryptic concentration by the total volume). I’ve done this several times and gotten pretty consistent results.
They are shedding a few trillion (10^12) genomes/day.
4/
What does this tell us? How much tissue is infected? It’s impossible to know for sure. Chronically infected cells probably don't release much, but acutely infected cells produce a lot more. I gather a typical output in the lab is around 1,000 virus per infected cell.
5/
If we assume we are getting 1,000 viral particles per infected cell, that would mean there are at least a billion infected cells. The density of monolayer epithelial cells is around 300k cells/sq cm. A billion cells would represent around 3.5 square feet of epithelial tissue!
6/
Don’t get me wrong. The intestines have a huge surface are and 3 square feet is a tiny fraction of the total.
But it’s still a massive infection, no matter how you slice it.
7/
I do not know of any persistent infections that shed this much virus without killing the patient. (Correct me if I’m wrong). The closest would probably be HCV, an infection that often ends in liver cancer.
8/
My point is that this patient is not well, even if they don’t know it, but they could probably be helped if they were identified.
9/
How do you figure out if you have a COVID GI infection. Most rapid antigen test are not explicitly for stool. However, I know of at least one that is. The instructions from that test say to mix a ‘matchhead’ worth of feces with the buffer.
10/

dyonmedical.com/en/corona-ag-a… Image
I can tell you that with very positive wastewater samples we got a positive by just sticking the swab into the wastewater before adding it to the buffer. Either way, it is essential to use the buffer provided or the test doesn’t work.
11/
If you do get a positive reading, I would suggest having someone else try with the same kind of test with their feces to be sure it isn’t a false positive. Weird shit happens.
12/
If you are the individual, let me know. There is a lab in the US that can do 'official' tests for COVID in stool, and there are doctors that I can put you in contact with that would like to try to help you.
13/
What's more, if we can figure out how these infections occur, and how to treat them, it could potentially help out a whole lot of people.
14/ Image
Two comments I should have made in my thread.

Washington Court House is a town of 15k (not an actual courthouse).

I haven't invaded anyone's privacy. Approximately 1600 people commute between Columbus and WCH. That isn't enough information to pinpoint the source.

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More from @SolidEvidence

Jun 12
Our latest cryptic lineage paper was accepted in PLoS Pathogens.

This paper has some nuanced implications about the origins of SARS-CoV-2.
1/
journals.plos.org/plospathogens/…
There haven’t been a ton of changes to the manuscript since I wrote a post on the preprint, so I’ll make this summary brief and focus on the things that changed.
2/
Cryptic lineages are anachronistic, evolutionarily advanced SARS-CoV-2 lineages detected from wastewater. We are pretty certain they are all from persistent infections.

We developed techniques for finding these lineages and partially reconstruction their genomes.
3/ Image
Read 11 tweets
Jun 6
This is so cool.

I’m pleased to share version 1.0 of our new dashboard for displaying data from our wastewater metagenomic project.

This is a collaborative projected between MU, U. Wisc @dho, and SecureBio; funded by Inkfish and Open Philanthropy.
1/
lungfish-science.github.io/wastewater-das…
For the last 18 months we have been getting weekly composite wastewater samples, isolating the viral fractions (the virome) and randomly sequencing everything.

We average about 1 billion reads per sample.
2/
The project started with Columbia, MO in late 2023, but we’ve expanded to include Chicago, Boston, Boise, and Riverside. We are doing other sites too (and expanding), but these are the first we are reporting.
3/ Image
Read 15 tweets
Apr 20
We are recruiting sewersheds for an expanding project. Basically, we want to learn everything that can be learned from wastewater.
Read on if you are interested.
1/ Image
This is a collaboration with SecureBio that started about 18 months.

Basically, we isolate the viral fraction from wastewater and sequence the crap out of it (~1 billion reads/sample). This is unbiased sequencing; we don’t want to miss anything.
2/
securebio.org
There are three main levels to the analysis of the wastewater virome.
The first is SecureBio’s main focus, which is novel pathogen detection with a particular focus on engineered pathogens.
3/
naobservatory.org/blog/detecting…
Read 16 tweets
Apr 19
This battle between Harvard and the administration is so befuddling. The latest plot twist makes less sense than the last season of Lost.

Let me give a very quick summary for those not following along.
1/11
The last few weeks Harvard had been talking with the administration about concerns over antisemitism on campuses, but the talks lacked details, and Harvard was told that they would get a letter last Friday with more specifics.
2/
Then last Friday Harvard got an email from the acting general counsel of HHS with a scorched earth list of demands that would have effectively ended Harvard’s autonomy in hiring, admissions and curriculum.

Here’s the letter.
3/
nytimes.com/interactive/20…
Read 11 tweets
Apr 12
Last month there was an announcement that I thought was a major advancement in world health, but it got little attention.
I thought I would tell you all a little bit about it and why it is so important.
1/25
This breakthrough has to do with HIV, which was a zoonotic pathogen. The progenitor of HIV infects chimpanzees in Cameroon.

No one knows exactly when or how HIV crossed into humans, but the first undisputed HIV patient sample (discovered retrospectively) was from 1959 in what is now the Democratic Republic of Congo.Image
HIV smoldered for decades before becoming widespread in the early 80s.
At the time, being diagnosed with an HIV infection was a death sentence.
There was no real cure (still isn’t) and no treatment. By any measure, HIV was one of the worst diseases of the last century.
3/
nature.com/articles/d4158…Image
Read 25 tweets
Apr 6
I briefly thought the SA BA.3.2 was in the US, but it turns out the virus was just messing with me again.

This was kind of interesting though.
1/
We've been screening all of the new wastewater data a few times a week for signs of BA.3.2.

One of the many screens we have is looking for reads that have C21846T+T21864C together, which are in BA.3.2 but no current lineages (it works better to look for pairs of changes).

2/
This week we had a hit. This was the genotype of the read:

C21621A|(S:T20N) A21626G|(S:T22A) T21657C|(S:F32S) T21695C|(S:S45P) A21712T|(S:S50S) CATGCTAT21758-21765del C21767-21767del C21846T|(S:T95I) T21864C|(SI101T) TTA21890-21892del|

3/
Read 9 tweets

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