The Animal Origins of Coronavirus and Flu | Hacker News Reader

The Animal Origins of Coronavirus and Flu

quantamagazine.org

69 pointsbainsfather57 comments

An early 2019 review paper[0] by Chinese authors has this to say in its abstract:

During the past two decades, three zoonotic coronaviruses have been identified as the cause of large-scale disease outbreaks–Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and Swine Acute Diarrhea Syndrome (SADS). SARS and MERS emerged in 2003 and 2012, respectively, and caused a worldwide pandemic that claimed thousands of human lives, while SADS struck the swine industry in 2017. They have common characteristics, such as they are all highly pathogenic to humans or livestock, their agents originated from bats, and two of them originated in China. Thus, it is highly likely that future SARS- or MERS-like coronavirus outbreaks will originate from bats, and there is an increased probability that this will occur in China. Therefore, the investigation of bat coronaviruses becomes an urgent issue for the detection of early warning signs, which in turn minimizes the impact of such future outbreaks in China. The purpose of the review is to summarize the current knowledge on viral diversity, reservoir hosts, and the geographical distributions of bat coronaviruses in China, and eventually we aim to predict virus hotspots and their cross-species transmission potential.

Is this prescient or purely coincidental or something else?

[0] https://www.mdpi.com/1999-4915/11/3/210/htm

Should be noted that the numbers in the intro are a bit off, the U.S. now has 57 cases.

https://bnonews.com/index.php/2020/02/the-latest-coronavirus...

Is there any sense for how accurate the case numbers are?

I've been thinking about it and I can't fathom how we would know of every case.

What percentage of adults who get the seasonal flu go see a doctor and get diagnosed, 10%? Coronavirus symptoms mimic the flu and can even by asymptomatic in people, meaning people can easily attribute symptoms to a bad cold/flu or not even notice them. On average someone with coronavirus spreads it to 3-4 other people. It's estimated that the virus started infecting people in early January, but China didn't start quarantining people until 3 weeks later or so.

I just don't see the math adding up, all it takes is a handful of people not seeking treatment in order for it to start spreading without our knowledge. There has to be thousands of additional cases around the world of that just aren't diagnosed, which is how we're suddenly seeing unexpected diagnoses in places without any previous outbreak like Iran.

> It's estimated that the virus started infecting people in early January

December 2019. That's why it is called COVID-19 to begin with, because it was first detected in 2019.

We can't even test for it properly in the US right now:

https://www.washingtonpost.com/health/2020/02/25/cdc-coronav...

And yeah, there are going to be a bunch of people here who won't seek help unless it gets really bad, and who will go to their jobs even if they feel crummy because they need the money, thus spreading it farther and more rapidly.

BTW, we were warned: https://www.washingtonpost.com/national/health-science/the-t...

Our healthcare system is really going to bite us here too - people are extremely hesitant to seek medical care since there's such a crapshoot of costs that you could pay.

(e.g. the story of the person who was fearful after developing flu systems after traveling to China so he checked into the ER for testing and got a $3,500 bill that 'might' be knocked down to $1,400 if he provides 3 years of medical history to prove it wasn't a preexisting condition: https://www.miamiherald.com/news/health-care/article24047680...)

So we have people who don't want to miss work and people who won't seek medical care unless they're in the later stages of the disease to avoid thousands of dollars of cost. Hopefully it peters out but this could get really ugly.

The US has tested a grand total of 445 persons since the beginning of the outbreak, according to this CDC page updated today, Feb 26. https://www.cdc.gov/coronavirus/2019-ncov/cases-in-us.html For comparison South Korea is testing several thousands per day.

To a lot of people it's pretty obvious that there are a lot of undiagnosed cases in the wild. They are not testing anyone unless you are coming from a known risk area, which means by definition they can't detect local community outbreaks.

Note that 40 of these are assigned to the cruise ship off Japan.

Fun fact: Coronavirus also recognises sialic acids (but they need an extra acetylation on top).

Fun fact 2: Sialic acids are important for protecting your gut / balancing the microbiome.

Fun fact 3: Bats apparently have a much simpler microbiome (less weight, better flying), and can tolerate low levels of coronavirus infection.

I would bet the closest non-flying relative of a bat would get respiratory infections too.

Bats really do seem to serve as viral reservoirs at an exceptionally high rate[1]. SARS, MERS, coronavirus and ebola all likely seem to have originated in bats.

One thing we may have to consider is a policy of bat eradication. At least in populated areas. It would have some ecological consequences, but the risk of mass pandemic probably outweighs that cost.

[1]https://books.google.com/books?hl=en&lr=&id=JnBpAgAAQBAJ&oi=...

You could also replace "bats" by "humans" in your sentence ;)

Getting people to stop eating bats would get us 95% of the benefit for 5% the effort.

Removing bats would create millionary damages in agriculture and would hit specially hard the tropical fruitculture. Kiling millions from famine and collapsing the ecology of tropical rainforests just to avoid a disease with a 96% probability of surviving is a really bad idea.

What's your opinion on Kudzu or Himalayan Blackberry as erosion control devices?

I don't often say this outright, but that's a dumb idea.

"Insectivorous bats in particular are especially helpful to farmers, as they control populations of agricultural pests... It has been estimated that bats save the agricultural industry of the United States anywhere from $3.7 billion to $53 billion per year in pesticides and damage to crops."[1]

1. https://en.wikipedia.org/wiki/Bat#Economics

> It has been estimated that bats save the agricultural industry of the United States anywhere from $3.7 billion to $53 billion per year in pesticides and damage to crops

In comparison, the coronavirus scare has wiped out $1.5 trillion from US equity valuations just in the past two days. Even taking the higher end of that estimate, preventing one coronavirus epidemic every 20 years still passes cost benefit analysis.

I do not consider vagaries of the stock market a valid reason to potentially wipe out an entire species.

More than that, you correctly identify it as a scare, which should be a clear indication how a short-sighted policy that may be.

Valuations != realized losses.

Not to mention eradication efforts are expensive and can have their own unintended consequences. Offer a bounty, and now you have people breeding bats for the bounties. Introduce a bat-specific disease and it may mutate into something else. A bat-specific poison could turn out to poison things we care about.

Like seriously, it's a stupid idea. I'm sad I wasted so much time even debating you.

> One thing we may have to consider is a policy of bat eradication.

Holy crap! This is a bad idea. Just leave the bats alone. They serve as an apex predator to provide balance to the natural environment.

> Fun fact: Coronavirus also recognises sialic acids (but they need an extra acetylation on top).

What do you mean by "recognises" here? Is sialic acid something that helps the coronavirus or something that hinders it?

The article describes how influenza viruses (not coronaviruses) use sialic acid to bind to the upper respiratory tract.

Edit: a letter.

I may have been a little hasty, which is to say COVID-19 might not recognise sialic acids. Which puts a bit of a dent in my theory.

But Sialic acids are really interesting!

i thought humans are just another animal. why the surprise about diseases jumping from other animals to humans

There’s no surprise, zoonotic viruses are well known. That said, viruses are usually highly adapted to a specific host. Jumping host species isn’t trivial, and the mechanisms for how this happens are worth exploring.

The bulk of our diseases are zoonotic in nature.

https://en.wikipedia.org/wiki/Zoonosis

Has the figure at 61%.

Sure, but here is a key line from the Wikipedia article you reference: "Most human diseases originated in other animals; however, only diseases that routinely involve non-human to human transmission, such as rabies, are considered direct zoonosis"

You aren't going to catch the current coronavirus from your dog.

True. But you could catch Rabies.

But usually zoonotic diseases are especially deadly since killing the host is not in a parasites best interest but new diseases haven't worked out an equilibrium with the victim species yet.

https://aeon.co/essays/when-bacteria-kill-us-it-s-more-accid...

Where are you seeing surprise?

The word "animal" is often used to mean "non-human animal." Context is key. I bet your locality has an Animal Control department, and you understand from context that it referes to non-human animals.

Jumping species tends to be a rare event with regard to diseases. But it is an important event, hence the article.

As with other attempts at sparking discussions on the origin [1], I'm not a virologist, just a bystander whose curiosity was piqued by the proximity of the sole lab in all of China that's equipped to handle/research extremely infectious viruses and that of the outbreak.

My observations (all facts)

1. Proximity of outbreak to sole advanced virology lab in all of China, suspicious

2. Publications ( https://jvi.asm.org/content/82/4/1899 )from lab suggest they were dealing with CoVid-19 like viruses for a while.

3. State of China would strongly deny/cover-up the lab to be the cause of outbreak, even if that did happen. I'm not suggesting they engineered the virus, just suggesting that they were researching animals with the virus, and a freak case of violating safety protocol let to the virus leaking to the nearby seafood market. Again - attributing this to clumsiness, not malice

Given the above, I think an investigative journalist would find the circumstances fertile enough for a deep investigation. Given how hard it is to identify patient zero of the outbreak, I think journalists need to go down this path of investigation

[1]: https://news.ycombinator.com/item?id=22424013

Given the above, I think you're grasping at straws.

There are US based researches on it already, and the evidence so far is it's not engineered. Your observations don't include all relevant facts, hence the conclusion can still be wrong. Like scientists in 18th century had all kind of weird ideas based on the facts they observed about the world. In today's world, for most of us, especially non experts on the fields, what really matters is all the facts out there that we don't know (or chose to ignore).

http://virological.org/t/the-proximal-origin-of-sars-cov-2/3...

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