Coronavirus: Belgian woman infected her cat | Hacker News Reader

Coronavirus: Belgian woman infected her cat

brusselstimes.com

62 pointsevo_932 comments

I can't imagine it's terribly likely, but imagine if you infected your outdoor cat, which then infected other neighbourhood cats, which then infected people who were otherwise isolating themselves?

It's like a diabolical apocalyptic sci-fi plot twist.

The truly diabolical twist is a nefarious virus mutation in the pet strain, for a 2nd deadly wave after general societal fatigue.

Earlier, WHO tested canines to see if they could contract the virus. After extensive quarantine and testing, WHO determined the dogs could not carry the virus and released them back to their owners.

That's right, WHO let the dogs out.

(Downvote as you must. It was worth it.)

Woofff..wof..wooof

Assuming virus structure doesn't change inside pets, why pet to human transmission is not possible? Shouldn't it be very likely?

You've a virus which can go from humans to pets and reverse, why? Any other virus where it's proven to be only one way street?

Could be an old theory, but the popular theory was it transferred from bats to humans, so yeah, this will probably happen. What this case doesn't say if it's readily transmissible between cats or between cats and humans. For all we know, people get viruses from other species all the time, the virus doesn't transmit well, so it stops there.

No. Viruses from humans cannot be carried by dogs or other pets, except in very extreme cases. Stastically speaking it doesn’t happen and it’s not something to worry about.

Rabies, influenzas, haemorrhagic fevers, West Nile, coronaviruses, and Zika might like to have a word with you on the subject.

Rabies is one of millions of viruses, it’s very very rare for a new virus to jump from one host species to another new species. Covid 19 already jumped from bats to people, it would need to mutate again to survive in a pet and spread via that vector.

Rabies is one of many viruses, but one of relatively few that cause disease in humans. From the NY Times the other day: https://www.nytimes.com/2020/03/24/science/viruses-coranavir...

> Covid 19 already jumped from bats to people, it would need to mutate again to survive in a pet and spread via that vector.

I don't see it as unreasonable to think that if it can cross from one mammal to another mammal, that makes it more likely to be able to cross to a third mammal. To make the crossing from bats to humans, it has to be doing something that works in both bats and humans, exploiting some feature that is common to both. But a feature common to bats and humans is much more likely to be also shared with dogs than a feature that humans have and bats don't.

This is the same principle that tells us that while it's rare for a virus to cross from infecting bats to infecting humans, it's much, much rarer for one to cross from infecting grasshoppers to infecting humans.

There's an interesting manuscript (caveat emptor) I found related to this[1] that states:

"2019-nCoV RBD likely recognizes ACE2 from pigs, ferrets, cats, orangutans, monkeys and humans with similar efficiency, because these ACE2 molecules are identical or similar in the critical virus-binding residues."

Not being a biologist or virologist, I don't know how true this is, but it may suggest this incident with the cat did in fact happen.

[1] https://jvi.asm.org/content/jvi/early/2020/01/23/JVI.00127-2...

Wonder how long the virus can survive on the fur of a pet. This is very different than the animal being infected and becoming a production factory for a virus but if we're being cautious about spreading the virus through contact with shared objects, pets seem like they could be a vector for a period of time. Perhaps a day or two?

The observation is sound. And also note that pets may be much more likely than (adult) humans to go into contact with some things and areas contaminated by saliva.

As for the stability, unless fur is more hostile than plastic or stainless steel, detectable viable virus at 72 hours is indicated in this recent article by van Doremalen et al.

https://www.nejm.org/doi/10.1056/NEJMc2004973

Experience from other coronaviruses, including SARS-CoV-1 and MERS-CoV, shows even longer persistence for some surfaces and environmental conditions. Please see Table I in Kampf et al. this January

https://www.journalofhospitalinfection.com/article/S0195-670...

Even if the virus is transferable between species, pets aren’t a particularly worrying vector. Most pets only have contact with a few humans, and those humans usually already have contact with each other.

Places like kennels and dog parks can increase the pet to pet transmission, but if a city locks down then those opportunities decrease as well. So worrying about pets won’t change any of our current approaches.

How about Istanbul? Loads of street cats there.

Street cats and most other feral animals in a city don’t have a lot of contact with humans, otherwise they get captured. Even with people leaving food out for them they do their own social distancing pretty well. You nearly need a death cult trying to get the disease before feral animals are a big enough problem to direct policy.

Is capturing even a thing in Istanbul? AFAIK they maintain a very friendly relationship between humans and cats.

I have been wondering about this myself. I have a cat that lives entirely outside, the second sweetest cat ever. If I get sick I sure don't want to infect my cat. Now, I wouldn't mind if the cat caught it, was not sick herself and then passed it on to some of the rat population around here as long as the rats got sick.

Also, are there any reports that this virus can jump to birds like chickens? I have been looking for chickens since eggs seem to be in short supply around here.

Good luck to all of y'all.

What? How could a cat pass anything on to a rat?

You think rats go looking for cats to snuggle up with? Prey animals generally try to avoid their predictors.

My cat plays with the rats and mice she catches before she kills them to eat. Even then she rarely eats all of the animal. Brains seem to be her preference since she eats the heads and leaves most of the rest on the porch. Some of the small animals she catches escape because she gets bored or distracted when someone comes out the door to see what all the commotion is about.

With that said, you're right, it doesn't make any sense that a rat would live long enough to catch anything in an encounter with a cat.

> What? How could a cat pass anything on to a rat?

Everybody poops.

Everybody eats and drinks.

Sometimes these two overlap more than is sanitary.

It's not a virus, but check out the parasite toxoplasma gondii for an example of an organism that uses this mechanism to get from cats (it only can reproduce in cat intestines) to rats (where it lives in their brains).

It needs to get back to cats from the rats when it is time to reproduce, which is the really interesting part of its life cycle. It doesn't just wait around on the off chance a cat will happen to eat the rat. No, it alters the rat's brain to make the rat lose its fear of the smell of cat urine. Normally, rats avoid territory marked by cats, but not those with a toxoplasma gondii infestation. It even makes male rats confuse that smell with that of a female rat, so they actually end up seeking out cats.

Truly something out of a horror movie [1].

PS: it's also not uncommon in humans.

[1] https://www.smithsonianmag.com/science-nature/the-parasite-t...

Perhaps someone with a better understanding of virology can clarify this for me.

My understanding is that the coronavirus binds to relatively generic cell receptors present on lots of different cell types (ACE-2 and possibly others) and this is responsible for the wide variety of symptoms, depending on which of the many susceptible areas of the body get infected first.

This may also enable lots of different species with these similar generic receptors to become infected. This virus seems like the ultimate generalist.

Hardly ultimate, but coronaviruses are apparently (in)famous for a relatively high propensity to cross species barriers.

This review from 2017 looks very relevant https://doi.org/10.1016/j.coviro.2017.01.002

I'll leave the rest to people who may have specialist level competence on the topic.

This is weird.

> the cheetahs, but developed no overt symptoms [6]. Also, experimental transmission of the Aju-CoV to three domestic kittens failed to cause disease [6]. Perhaps also relevant is that when the human SARS-CoV was induced in domestic cats, they developed no symptoms

1. https://www.cell.com/current-biology/pdf/S0960-9822(04)00143...

I also find this weirdly dubious, but not impossible. I do know that to study human coronavirus in mice, we had to create a mouse line expressing the human ACE2 protein.

I just did a quick protein alignment and the %sequence identity between human and select animals are:

Bats: 81.5% Mice: 81.9% Dogs: 84.1% Cats: 85.2%

Related: further corroboration of infection in the dogs in Hong Kong.

https://www.scmp.com/news/hong-kong/health-environment/artic...

And pets will practice social distancing even worse than people, if you can imagine that.

Cats are probably better at social distancing than dogs.

Tell that to Hillary, who insists on sitting on my wife's chest any time she lies down. Or Henry who insists on sleeping on my shoulder when I lie down.

Good luck teaching social distance to cats and dogs.

Reply on news.ycombinator.com