
SARS-CoV-2 titers in wastewater are higher than expected from confirmed cases - guscost
https://www.medrxiv.org/content/10.1101/2020.04.05.20051540v1
======
epistasis
I don't think that HN is a good venue for discussion of specialized preprints
that have highly surprising results, in topics that are moving extremely
quickly.

Too few people in this community are able to evaluate the information
contained, which leads to lots of pointless speculation, and lots of
misinformation. Despite working in biology for 20 years, I would not trust
_any_ of my own interpretations of this pre-print.

The only people who I would trust are named specialists in this field, that
are willing to stake bits of their reputation on what they say.

The only venue where that is happening in the public is on Twitter.

~~~
ianai
I agree that HN is not capable of digesting this study reasonably not
meaningfully. I question using Twitter for anything meaningful though.

~~~
epistasis
Twitter is often extremely useful for scientific fields, and in many ways is
perfect for it. You can post a figure and legend, tag people that may find it
interesting, and start threaded discussions. It's all in the public, with no
invitations or closed doors, so it is open to discovery by that dozen or two
dozen people in the world that may be interested.

Science is the ultimate long-tail of super-specialized interests with
extremely small audiences, and Twitter is perfect for connecting those people
with extremely esoteric interests.

There is a lot of crap, but science Twitter is also the only reason I'm on it.
Sadly, my own biases against Twitter Kept me off it for 8+ years, but after I
started finding the right people to follow, a whole new world opened up, and
it is now a vital tool for me to navigate the literature and learn quickly
which new tools are best.

~~~
random314
How does it compare with following the same account on Facebook?

~~~
epistasis
I don't know of anybody that uses Facebook for science discussion, but I did
know many that were using Twitter for science, which is what finally drew me
in.

Facebook seems like a much worse fit than even Twitter for discussion, but I
would potentially check it out if somebody I trusted had found it useful.

------
Symmetry
Well, yes. Even areas of the world with high levels of testing and low levels
of infection are going to be missing some cases. Here in MA where a full 30%
of tests are coming back positive[1] it would be surprising if actual
infections weren't a multiple of confirmed cases. But things are probably much
better than they were in February where estimates of the ration are that we
were factor of 100 or more behind actual cases.

[1][https://i.redd.it/ajxsj8jxyur41.png](https://i.redd.it/ajxsj8jxyur41.png)

~~~
hprotagonist
19.9% per
[https://dashboard.cityofboston.gov/t/Guest_Access_Enabled/vi...](https://dashboard.cityofboston.gov/t/Guest_Access_Enabled/views/COVID-19/Dashboard1?%3AshowAppBanner=false&%3Adisplay_count=n&%3AshowVizHome=n&%3Aorigin=viz_share_link&%3AisGuestRedirectFromVizportal=y&%3Aembed=y)

i wonder why the disparity?

~~~
lsllc
On the graphic it's "29% of todays tests were positive", not of overall tests
which indeed stands at 19.94% positive (18941/94958). The graphic is incorrect
with 16% of all tests positive.

EDIT: Creator of the graphic is /u/oldgrimalkin who posts these each afternoon
in /r/CoronavirusMa

------
gwbas1c
I live in MA and got very sick on Feb 26, then had a horrible cold. My wife is
a doctor, and she thought I just had one of the many things going around.

I asked her if it was COVID-19 and she looked at the CDC's web site and said
she didn't think so. Then a week later she flew out of Logan to spend a
weekend in LA. I also went skiing in New Hampshire twice, and went to two
networking events!

Throughout March I had symptoms that I never had in my life... I couldn't get
a test! The symptoms went away after 4 weeks.

Did I have it? I have no idea, but if I got it, it most likely came from her
or my kids, who all felt kinda wonky in mid February. My wife had a very bad
headache two weeks before I got sick.

~~~
jrockway
Same! In mid-February I went to a party. A couple of my friends were getting
over "a really weird cold" that "everyone in the office had". A few days
later, I was sick with the same symptoms, mostly a dry cough. I thought
nothing of it except that it was very unusual for the kinds of colds that I
usually get (I am a sore throat and aches guy, so I was thrown off by not
aching and having a cough). I had this for a couple weeks.

I wasn't working at the time, but it was minor enough that I would have gone
to work. That is also very rare for me, usually I am out of commission for a
week when I get a cold.

Was it Coronavirus? I have no way of knowing. But looking back, it seems very
suspicious. An extra-infectious cold with the same symptoms of Coronavirus
going around the New York office populated by people that travel
internationally extensively? You have to wonder.

I kind of assume that Coronavirus cases are massively underreported. Given
that 20% of cases are people without symptoms, what would prompt them to get
tested? And all the advice I've read is along the lines of "if you think you
have it, don't get tested, just stay home and get over it". With that advice,
I have to assume that many cases are not accounted for in the official data.
It does seem strange to me that if Coronavirus was circulating in New York in
mid-February that it didn't show up at all until early March "officially",
though. It's unlikely that not one person would have severe symptoms. For that
reason, I assume I'm not immune and am self-isolating like everyone else...
but if I can get an antibody test, I would love one. I am very curious as to
what happened there.

~~~
basch
Even if it wasnt Sars-COV-2, something odd was going around as early as
December and January, all over the country. Everyone who got it said it was
like nothing they had before. The cough was horrible, and it caused headaches
in less symptomatic people.

~~~
mywittyname
I'm kind of glad to hear other people reporting similar events. I too had a
really weird cold in Jan/Feb that left me coughing and very short of breath
after simple activities like running up the stairs. Before the lockdown, I was
a 5-day-a-week gym-goer, so this was very unusual.

It wasn't until the shutdown occurred that I read about the symptoms and noted
that shortness of breath was a tell-tale symptom. I also worked at a place
with offices in Shanghai and many Chinese nationals working locally.

------
floatingatoll
The paper includes a disclaimer:

> _MM and NG are cofounders of Biobot Analytics. EJA is advisor to Biobot. NE
> and CD are employees at Biobot. All these authors hold shares in the
> company._

Another comment suggests that Biobot is YC. As far as I can tell, Biobot has
never posted a Launch HN, but they did post a Covid page 3 weeks ago:

[https://news.ycombinator.com/item?id=22627746](https://news.ycombinator.com/item?id=22627746)

They were in the news in 2018 for testing wastewater to measure the opioid
crisis, but I can't find any HN discussions about _any_ link or story that I
can find myself, or from their list of media posts.

[https://www.biobot.io/media](https://www.biobot.io/media)

Among those links are a video interview / product demo (Cheddar) and a podcast
interview (Latina Founders).

------
fxj
According to the Heinsberg Study in Germany, the infection rate was as high as
15% and the mortality rate in the town would be as low as 0.37 per cent.

Germany launched the Heinsberg Protocol study to examine the rural town of
Gangelt in the region of Heinsberg, where the first virus fatalities occurred.

[https://www.thenational.ae/world/germany-s-wuhan-
has-15-per-...](https://www.thenational.ae/world/germany-s-wuhan-has-15-per-
cent-infection-rate-and-low-death-toll-1.1004050)

During recent weeks, his team completed substantial research conducted through
surveys and investigations in homes across the Heinsberg region - where more
than 1,400 confirmed cases had been reported. Heinsberg has an approximate
population of 250,000 inhabitants and has confirmed 46 coronavirus-related
deaths.

These research findings have already provided some indication on how the virus
works, as Streeck clarified:

“There is no significant risk of catching the disease when you go shopping.
Severe outbreaks of the infection were always a result of people being closer
together over a longer period of time, for example the après- ski parties in
Ischgl, Austria.” He could also not find any evidence of ‘living’ viruses on
surfaces. “When we took samples from door handles, phones or toilets it has
not been possible to cultivate the virus in the laboratory on the basis of
these swabs….”

“To actually 'get' the virus it would be necessary that someone coughs into
their hand, immediately touches a door knob and then straight after that
another person grasps the handle and goes on to touches their face.” Streeck
therefore believes that there is little chance of transmission through contact
with so-called contaminated surfaces.

[https://today.rtl.lu/news/science-and-
environment/a/1498185....](https://today.rtl.lu/news/science-and-
environment/a/1498185.html)

~~~
Endlessly
Any claim without sufficient data and reproducible results that the virus is
unable to transfer via a surface, to me, borders on criminal negligence, given
real research shows this is inaccurate.

As a counter to claim virus is “unable to live on surfaces”:

Virus was found 17-days after cabins on a cruise ship were vacated:
[https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e3.htm](https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e3.htm)

Coronaviruses: How long can they survive on surfaces?
[https://www.medicalnewstoday.com/articles/coronaviruses-
how-...](https://www.medicalnewstoday.com/articles/coronaviruses-how-long-can-
they-survive-on-surfaces)

First link is ambiguous as to if the samples taken were “toxic” enough to
result in infection, but the second link makes it clear that virus survives on
surfaces for days in quantities large enough to infect someone.

~~~
new299
> SARS-CoV-2 RNA was identified on a variety of surfaces in cabins of both
> symptomatic and asymptomatic infected passengers up to 17 days after cabins

Unless there’s more to this, it doesn’t seem very useful to me. It seems
obvious to me that you’ll find some RNA. However it would likely be
damaged/fragmented.

I’m not sure about the second reference, it would be interesting to dig out
the original study.

~~~
Endlessly
Research is linked to in the media coverage:

[https://www.journalofhospitalinfection.com/article/S0195-670...](https://www.journalofhospitalinfection.com/article/S0195-6701\(20\)30046-3/fulltext)

~~~
fxj
Conclusions

Human coronaviruses can remain infectious on inanimate surfaces for up to 9
days. Surface disinfection with 0.1% sodium hypochlorite or 62–71% ethanol
significantly reduces coronavirus infectivity on surfaces within 1 min
exposure time. We expect a similar effect against the SARS-CoV-2.

------
kickscondor
Finding out that we all have it already would be one of the more humorous
endings to this story.

~~~
whatshisface
There was some data from Iceland that showed about 50% of cases being
asymptomatic. That's more optimistic than we saw originally, but not as
optimistic as the most optimistic scenarios proposed.

~~~
scurvy
I truly doubt the asymptomatic carrier and spreader myth. People lie to their
doctors all the time. Why wouldn't they lie to a stranger taking a poll of
their health?

Sure, the virus will hit some people much harder than others. There's a
component there yet to be discovered. But those exposed must have some sort of
response, even if it's just a series of stronger than usual headaches. Stuff
like that goes under reported because "oh that was just a random headache".
Said person might drink a lot and deal with hangovers so headaches are
expected. Whatever.

My point is that these studies are not very thorough in following up on the
response quality or even a requery 2 weeks later when symptoms got much worse.

Lies,damn lies, and statistics from personal health studies.

~~~
Reason077
> _" I truly doubt the asymptomatic carrier and spreader myth."_

I partially agree. If you're infectious, then the virus is multiplying inside
your body. Eventually your immune system is going to react to that and you'll
feel it.

But it's also quite possible that you can be infectious _before_ you feel ill.

~~~
scurvy
Definitely! That's why I mentioned no lack of requery 2 weeks later. "Oh I was
fine then, but now I feel horrible." That is missed in these studies. They're
flawed!

------
_wldu
Researchers are finding that COVID-19 testing has roughly 33% false negatives:
[https://www.wsj.com/articles/questions-about-accuracy-of-
cor...](https://www.wsj.com/articles/questions-about-accuracy-of-coronavirus-
tests-sow-worry-11585836001?mod=e2tw)

The LabCorp test is not FDA cleared or approved and is being used under an
emergency act.

 _" Testing was performed using the cobas(R) SARS-CoV-2 test. This test was
developed and its performance characteristics determined by LabCorp
Laboratories. This test has not been FDA cleared or approved. This test has
been authorized by FDA under an Emergency Use Authorization (EUA). This test
is only authorized for the duration of time the declaration that circumstances
exist justifying the authorization of the emergency use of in vitro diagnostic
tests for detection of SARS-CoV-2 virus and/or diagnosis of COVID-19 infection
under section 564(b)(1) of the Act, 21 U.S.C. 360bbb-3(b)(1), unless the
authorization is terminated or revoked sooner."_

The Quest test is not FDA approved either:
[https://www.questdiagnostics.com/dms/Documents/covid-19/SARS...](https://www.questdiagnostics.com/dms/Documents/covid-19/SARSCoV-2_Patient_Fact_Sheet.pdf)

 _" It is possible for this test to give a negative result that is incorrect
(false negative) in some people with COVID-19. This means that you could
possibly still have COVID-19 even though the test is negative."_

 _" This test is not yet approved or cleared or authorized by the United
States Food and Drug Administration (FDA)."_

Due to this, it's hard to trust test results. It's a best effort and not
perfect.

~~~
xenonite
Well, each test is different though. More so, testing wastewater is also a
totally different story than testing humans. Although I find your comment
interesting, I don't see how this relates to the topic of wastewater analysis.

------
owenmarshall
This is the same approach used for global polio surveillance:
[http://polioeradication.org/polio-today/polio-
now/surveillan...](http://polioeradication.org/polio-today/polio-
now/surveillance-indicators/)

------
snovv_crash
This reminds me strongly of the methods used in Neal Stephensons's novel
Zodiac, where they follow sewerage pipes to determine where the source of an
infection is.

------
Zenst
The whole avenue of analysiing waste water when you have centeralised
procesisng of the inhabitants as a finger in the air feel upon things is
already used in some avenues and like this, many more avenues of potential.
Sure it won't be exacting, but does give a feel for things in a way that is
very cost effective over alternatives in so many area's.

For example, drug usage - measuring the waste water for levels of cocaine, etc
etc etc is already used to some degree and proven in many studies.

Sure it won't say who, what or exactly were and with that, also anonymised and
ticks a few privacy box's in that respect. Let alone the aspect that your
fecies and urine and property that we all happily sign away to the water/waste
company and even pay them. They can do with it what they like if it comes down
to it, but in this approach, nobody is identified and it is more a finger in
the air measure of things and a good indication of any shifts/change overall
for the costs and speed of doing so.

Though personal toilets that will do some serious analysis of your waste for
health reasons may well be a big in japan joke phase, but certainly at some
level they do have merit and whilst the waste treatments today may be a good
overall feel, the market and technology will gradualy filter down into the
homes for those that want to be ontop of their health or just want that extra
level of safty.

Certainly a good initiative and practical approach, though such an approach
does depend upon a good waste/water infrastructure and that will be mostly
modern area's, towns cities and the like and for some area's, may not have
that high a percentage using such centralising waste management.

Though when we start tracking area's health media wise like we do weather and
get the poo forecast, that's when I know reality has caught up with my darkest
of humour.

------
whatshisface
If the number of cases are really as high as this paper suggests (5% infected)
then we are one or two weeks away from a death wave like nothing else. However
let's pay attention to the many caveats the authors point out about their
calculation, including the assumption that there are no particular individuals
who are shedding especially large quantities of virus.

~~~
rumanator
> then we are one or two weeks away from a death wave like nothing else

Just to put this sort of hyperbole into perspective, the Spanish Flu killed
between 50 and 100 million people.

The black plague was even worse.

Even if a death wave is coming, the "like nothing else" is a very short-
sighted remark.

~~~
caseymarquis
Note/Tangent: A quick search shows the black plague killed an estimated 25
million people over a century. Less than Spanish Flu, but a much higher
percentage of the population at the time. Up to 95% of Native Americans died
from diseases introduced from Europe. That's the largest percentage of a
population to ever die from disease that I've heard of, and is the primary
reason Native Americans are not the dominant population in the Americas today.
Whether there's potential for an unprecedented amount of deaths really depends
on how you measure things.

~~~
rumanator
> Note/Tangent: A quick search shows the black plague killed an estimated 25
> million people over a century.

Those estimates sound a bit off by a factor of 5 to 10 regarding deaths, and
they were concentrated in a 4 year period.

[https://en.wikipedia.org/wiki/Black_Death](https://en.wikipedia.org/wiki/Black_Death)

Apparently the black death is estimated to cause the death of between 30 to
60% of Europe's entire population.

~~~
caseymarquis
With you 100% that in relative terms we're not facing anything close to the
black death. Everything past this point is just me enjoying my day off by
learning about random things, and wanting to know what the actual answer is.

My original number was from a search for "How many people died from the black
plague.". The first result was a National Geographic article which stated the
25 million number occurring over a century. [1]

The linked Wikipedia article states 75 to 125 million, so the two disagree by
a factor of 3 to 5.

The Wikipedia article cites an Australian Broadcasting Corporation news
article for the 75 million number[2], and thus cites 'Anomalies and
Curiosities in Medicine' page 617 for the other number. The edition of AaCiM
available online -published in 1906- actually has the information on page 893.
[3] The information there doesn't match the Wikipedia article. The largest
number stated there is 75 million, and cites 'Le Moyen Age Médical', which
appears to have been published in 1896. [4] I found an English translation,
and the only number I saw was 25 million over 4 years. [5] It's not clear if
the author is referring only to Europe, but it seems likely. At this point, I
really need to take my dog out, but it seems to me that the vague answer is
that tens of millions of people died, many in a specific four year period.
Which, goes back to the idea that, in relative terms we're not dealing with
anything like the black plague, and that how you measure things is important.

[1] [https://www.nationalgeographic.com/science/health-and-
human-...](https://www.nationalgeographic.com/science/health-and-human-
body/human-diseases/the-plague/)

[2]
[http://www.abc.net.au/science/articles/2008/01/29/2149185.ht...](http://www.abc.net.au/science/articles/2008/01/29/2149185.htm)

[3]
[https://www.google.com/books/edition/Anomalies_and_Curiositi...](https://www.google.com/books/edition/Anomalies_and_Curiosities_of_Medicine/4k1rAAAAMAAJ?hl=en&gbpv=1&pg=PA893&printsec=frontcover&bsq=bubonic%20plague)

[4]
[https://collections.nlm.nih.gov/catalog/nlm:nlmuid-54930290R...](https://collections.nlm.nih.gov/catalog/nlm:nlmuid-54930290R-bk)

[5]
[https://collections.nlm.nih.gov/bookviewer?PID=nlm:nlmuid-54...](https://collections.nlm.nih.gov/bookviewer?PID=nlm:nlmuid-54930290R-bk#page/24/mode/2up)

------
ping_pong
A Danish study recently concluded that actual infection rates could be 30x-80x
higher than what is shown by positive test results. This could easily explain
the higher levels than expected and is potentially a good thing and bad thing.
It means that mortality is much much lower that expected.

[https://www.reddit.com/r/COVID19/comments/fxk917/covid19_in_...](https://www.reddit.com/r/COVID19/comments/fxk917/covid19_in_denmark_status_entering_week_6_of_the/fmuw8a8/)

(Google translation)

Google translate of section 4.1.2 (pg.27):

4.1.2. Revised planning basis Statens Serum Institut informs on the basis of
antibody studies in 1,000 blood donors in the Capital Region, lost in the
period 1-3. In April, 2.7% had been detected with antibodies, which, with a
sensitivity of 70%, corresponds to 3.5% of those examined had already been
infected with COVID-19. Statens Serum Institut states that if this figure is
transmitted to the entire population of the Capital Region, it is equivalent
to approx. 65,000 people may have been infected as early as 26 March. At this
time, 917 confirmed cases of infection were found in the region. This means
that there can be up to 70 times more infected in the community than confirmed
cases.

In the work of the State Serum Institute in modeling the development of the
epidemic in Denmark, on the basis of studies in, among other things, Iceland
and Germany, it has been decided to work with the real number of infected in
Denmark being 30-80 times higher than the number that remains. ver proven.

It is therefore estimated that the dark number is significantly higher than in
the first planning scenario, and it is estimated from the State Serum
Institute that for every detected infection case up to March 28, there may be
30-70, which are actually infected. This ratio will be affected by the number
of people who will be infected in the future.

Thus, there is probably much more widespread contagion in society than
previously thought. This does not have a direct impact on the planning basis
for the health care system, as the increased spread of infection is in a part
of the population who do not need hospital treatment and probably only to a
very limited extent have sought medical attention. It should also be noted
that it also means that the mortality rate of infection with SARS-CoV-2
(infection fatality rate, IFR) is lower than the mortality rate of registered
case fatality rate (CFR) and possibly lower than that of WHO have evaluated.
The WHO has estimated that the IFR is between 0.3-1.0 with wide variation
across age groups. With more precise knowledge of the dark figures, the IFR
for the COVID-19 epidemic in Denmark can be clarified and the expected
mortality will be accurately estimated.

The State Serum Institute states that over the coming weeks they will be able
to continuously monitor the development of immunity in the population through
cooperation with the blood banks, focused sample studies and testing for the
population's immune status in general.

The above also means that the previous assessment of the mortality in
connection with COVID-19 in Denmark is no longer true. When a more accurate
assessment of the actual prevalence of infection is obtained on the basis of
the epidemiologic surveillance and a precise IFR for the Danish epidemic is
estimated, a new and true mortality prognosis can be estimated.

The need for ordinary beds and intensive beds is evident from the modeling,
which will be continuously qualified.

TLDR: blood donor antibody testing indicates true infection rates are 30x-80x
higher than confirmed cases in Denmark and that 1.5 weeks ago ~3.5% of
Copenhagen’s population may have already been infected by Covid-19.

~~~
Symmetry
The relationship between the number of infections and the number of confirmed
cases is going to be hugely dependent on the number of tests and how they are
distributed. 80x higher is very plausible but the ratio is going to be very
country dependent. I'd be rather surprised if South Korea was more than 2x
off, but I could easily see Ethiopia being 5000x off right now.

~~~
guscost
Looks like South Korea has administered fewer tests per capita than Denmark,
but you're right that their numbers could be closer if those tests were more
effectively targeted.

~~~
Symmetry
If you have fewer infections and are able to allocate your tests to people who
came into contact with those infected then you _need_ fewer tests.

~~~
0xFFC
While what you are saying is logically coherent but it does not work in the
real world. How are you going to track all the people the infected people has
to contact with? How about asymptotic cases?

~~~
Symmetry
You don't have to be perfect, just good enough to get R under 1. It's been
working pretty well Taiwan, Singapore, and South Korea when combined with
moderate social distancing measures.

------
lidlin
The title of the article is deceiving as virus itself was never isolated from
wastewater. The authors used RT-PCR to test for the presence of a 150bp
segment of the SARS-CoV-2 genome. Although the presence of nucleic acid
implies that virus is there, infectious virus was not isolated in this study.

~~~
vikramkr
That is how you detect and characterize the biota of a water source quickly
and efficiently- quantitative pcr or rtpcr to detect viral load levels. What
would you expect they do instead?

------
dec0dedab0de
This is neat, but a little scary. If I'm understanding it correctly, they are
checking sewage for evidence of the virus, and estimating how many people have
it based on that. This would be really cool if it were common place, and
tested for all known viruses, drugs, fungus, bacteria, lead, whatever they can
find. This could be used to track the health of the population over time and
as it spreads. If it were publicly available this would be a great resource.

The scary part is what if they start making the sewage sites smaller and
smaller, or even just the collection locations to where its testing fewer
people. Then use that information to enact quarantines or investigations.

~~~
jimbokun
> Then use that information to enact quarantines or investigations.

That's exactly what we want!

Quarantine the specific areas where there is an outbreak, and relax the nation
wide quarantines currently being enacted in many countries.

~~~
zepto
Only if you have an extraordinarily transparent process for determining when a
quarantine is appropriate.

------
yters
If covid-19 is much less harmful than we originally thought, why were, and
still are, medical experts proposing such draconian measures without a clear
understanding of the true threat? Dr. Fauci, advisor to the president,
proposed the other day that no one should ever shake hands again, in order to
prevent spread. It is bizarre.

Even when the disease first started to spread, there were people making these
same points. In fact, most people thought the disease was no worse than a bad
flu or cold, hence the difficulty to institute lockdown type measures in the
first place. This is certainly not going to build trust in institutional
expertise on these matters. So, once the medical experts are actually right,
then they'll be ineffective at persuading people.

