Toxoplasmosis: The Cat Poop Parasite That's Probably in Your Brain | Hacker News Reader

Toxoplasmosis: The Cat Poop Parasite That's Probably in Your Brain

interestingengineering.com

84 pointsNicoJuicy37 comments

Articles like this are incredibly frustrating, as they raise very serious concerns, but fail to address very basic points:

- Does your body ever rid itself of this infection on its own?

- Are there any treatments for this disease?

- If there are treatments, is there any point in using them if you own cats? ie, will you simply be reinfected again in short order?

- Does the disease aerosol-ize with litter dust?

- Given that cats lick their butts and also walk in their litter box, is it even possible that careful litterbox handling could ever be a sufficient method for prevention?

- If this disease is so ubiquitous, how do we know it's harmful?

Ehhh, you are trying to spoil everything. With those questions answered all serious concerns become not so serious. Yes, people recover from it by themselves without even knowing they were infected. Yes, there is medicine for this. The only danger is for pregnant women as it might affect a baby. So pregnant women are tested.

For me this article is just some incarnation of http://paulgraham.com/submarine.html

> http://paulgraham.com/submarine.html

> Online, the answer tends to be a lot simpler. Most people who publish online write what they write for the simple reason that they want to. You can't see the fingerprints of PR firms all over the articles, as you can in so many print publications-- which is one of the reasons, though they may not consciously realize it, that readers trust bloggers more than Business Week.

> Whatever its flaws, the writing you find online is authentic. It's not mystery meat cooked up out of scraps of pitch letters and press releases, and pressed into molds of zippy journalese. It's people writing what they think.

God damn it, that gave me some _hard_ nostalgia for the Internet of 2005.

Yeah, that bit about writing online being "authentic" didn't age well. Hell, if my buddy's '05-era content farm was any indication, Graham was wrong when he wrote that.

That would actually provide useful information instead of just spreading fear mongering which... wasn't the intention of this article.

> Does your body ever rid itself of this infection on its own?

Sometimes, no. And then you'll take sulfadiazine and pyrimetamine and have the worst headache you can imagine.

> Are there any treatments for this disease?

For each manifestation of it, yes. To get rid of it, no. You'll have it forever inside your body. And in those times that you immunity is low it can manifest itself again.[1]

And then "Decreased visual acuity may occur as a result of macular involvement or severe vitreous inflammation" [0].

[0] https://www.reviewofophthalmology.com/article/how-to-diagnos...

[1] "However, the parasite remains in the person’s body in an inactive state. It can become reactivated if the person becomes immunosuppressed." https://www.cdc.gov/parasites/toxoplasmosis/disease.html

(edited: add more reference)

From what I remember from monograph I read about decade ago.

>Does your body ever rid itself of this infection on its own?

No, but it gets used to it.

>Are there any treatments for this disease?

Only for acute form. But it's usually latent and the cysts in the brain are treatment resistant.

>If this disease is so ubiquitous, how do we know it's harmful?

It lowers reaction speeds, inhibits fear, can cause reckless behaviour. There were found correlations between infection of Toxoplasma gondii and development of psychiatric illnesses like schizophrenia.

It's not even like direct contact with cats is the main vector of infection -

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1118145/

"Overall, eating raw or undercooked beef, lamb, or other meats; contact with soil; and travel outside the country were major sources of infection."

"direct contact with cats is irrelevant with respect to T gondii transmission"

It seems what's more important is keeping cats away from livestock.

>Does your body ever rid itself of this infection on its own?

Your body can drive it dormant, or eradicate it. Tough to know if either of these have happened definitively.

>Are there any treatments for this disease?

Yes, there are antiparasitics in the class of malaria drugs etc

>If there are treatments, is there any point in using them if you own cats? ie, will you simply be reinfected again in short order?

Probably no studies on reinfection but you can check

>Does the disease aerosol-ize with litter dust?

Yes

>Given that cats lick their butts and also walk in their litter box, is it even possible that careful litterbox handling could ever be a sufficient method for prevention?

Yes it is a significant mitigation

>If this disease is so ubiquitous, how do we know it's harmful?

You could ask the same thing about vaccines

This article does have a lot of fearmongering, but it is really important to be clear that pregnant women do need to take care, especially during their 3rd trimester.

I'm a fairly lucky victim of toxoplasmosis - I'm legally blind in one eye because the parasite rampaged through the retina with the end result being a lot of scar tissue and only a little peripheral vision left.

Tangential to this, it's amazing how far technology has come. I was diagnosed in the mid-80s, and that required going to a hospital that had specialists and the necessary equipment to take pictures of the retina, and the entire process took the better part of a day (waiting for the pictures to develop took quite a bit of that time, of course). By the late 90s, a few optometrists were getting the necessary equipment to do this during a normal eye exam, although it still required drops to dilate the pupils. Today many optometrists have equipment that don't require dilation and since they're using digital cameras, they can look at results immediately.

I grew up on a small farm with lots of cats and kittens. When I was a healthy 15 year old doing track/cross country, a lymph node swelled up. It was removed for a biopsy, and tests confirmed it was brimming with toxoplasmosis activity.

When I was 27, I had flashes in my eyes that turned out to be caused by posterior vitreous detachment[0] which left some small holes in each of my retinas. That could be unrelated -- I have severe astigmatism, and it happens to many as the vitreous hardens with age -- but I had to have laser sutures to prevent vision loss. (I still have irritating floaters and can't enjoy reading a book in bright conditions.) None of my three siblings had either of these issues.

[0] https://www.asrs.org/patients/retinal-diseases/9/posterior-v...

The article sounds so scary as if we were at some edge of cat poo based extermination. It seems that Covid really sharpen journalists skills to spread fear. The reality is much more boring, you will rarely get this disease if you adhere to not so complicated rituals like washing your hands and not eating raw meat.

The only real danger if for pregnant women, that's why pregnant women should be tested for toxoplasmosis (what is a routinely done) and take medicine in case of infection.

And the rest of us who even did not noticed they have T. gondii, well, let's keep that happy state of ignorance.

Putting my conspiracy theorist hat I would say some manufacturer of T. gondii test or medicine against it wants to increase sales...

It's not so new though. I recall hearing in the 90s about how cat poop bacteria affects owners, and it was euphemistically used to explain the "crazy" part of the proverbial Crazy Cat Lady. It seems there is a lot of truth in that.

Protazoan, not bacterium.

Although I don't have a control group for this I'm almost certain I have been exposed to T. Gondii when I was really young. Children, me included, were playing in public sandboxes, and child parks lined with sand. There were cats there, and I am certain I dug up something I now recognize as cat poop multiple times. Of course, then it was of no importance to me. For how I've been affected, people do describe me as lacking fear, over 20 years later. I have not done any tests though.

Toxoplasmosis is very attractive popsci horror theme.

You might want to wait for more research and data before you get too excited. Some solid research shows that it has no effect on humans (except from fetuses)

https://www.discovermagazine.com/health/the-myth-of-mind-alt...

Plus, after having the infection the human body develops effective antibodies. People that lived with cats likely have had an infection and hence antibodies.

Well, it does in your eyes. Posterior uveitis can cause severe degradation in your vision.

https://rarediseases.org/rare-diseases/posterior-uveitis/

It seems to be caused by multitude of various factors of which toxoplasmosis is not especially prominent one.

Given that in some countries double digit percentage of people has toxoplasmosis antibodies and since posterior uveitis is a rare disease it doesn't seem to be common effect of toxoplasmosis.

I'm not even sure why you mentioned it at all.

There's an aspect of toxoplasmosis that I think is interesting, but didn't show up in the (disappointingly sensationalistic) article, or in the comments so far: toxoplasmosis can result in significant personality changes, such as higher extroversion, aggression and sex drive.

https://www.scientificamerican.com/article/common-parasite-l...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5731508/#:~:tex....

I'd guess the chances of infection go up if you have a vegetable garden in a suburban environment. Cats use freshly turned soil as a litter tray and salad vegetables such as radishes and spring onions are often eaten raw.

I wonder if rabbit repellent also deters cats.

You can buy bottled coyote urine. Pretty sure that would work.

Woah. How is that even collected?

Yes, foxes eat cats also

Being eaten raw doesn't mean being eaten without washing. That should get rid of most of the stuff. My understanding is that cat litter is a danger factor because it gets dry and fecal matter particles get thrown in the surrounding air. Which wouldn't be a problem in the garden.

Scrub those vegetables well, friend!

Pedant's corner: if a minority of people have it (40 to 60 million in the U.S., as many as 2 billion worldwide) then how can you say it's "probably in your brain"? Is this article somehow targeted toward cat owners?

Not pedantic at all. The article headline and content are both written to sensationalize and maximize your fear response.

Personal anecdote: we had our two cats tested (adopted in LA, taken off the streets) and they were both negative.

Related, a recent study just discussed yesterday: https://news.ycombinator.com/item?id=27599085

I'll just leave this here : https://pubmed.ncbi.nlm.nih.gov/32777351/

Toxo was one of major diagnosis of AIDS way back when. Lots of people may have it. But a weak immune system may let it grow.

Yeah, last time I tested I had it. Don't know if its still there. No ill effects at all.

Never trust a human who chooses to cohabitate with an animal that sprays who knows what on the furniture, shreds upholstery, and shits in a box that said human must manually clean…

You’re missing out. Cats are amazing and make the best animal companions.

Agreed. My cat is my best buddy.

Just wait until you hear about babies

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