Cats and Their Brain-Controlling Parasites Are Targeting Your Children

No sandbox is safe, according to researchers at Johns Hopkins University. Photo: Flickr/popofatticus

Toxoplasma gondii, the protozoan parasite found in cats everywhere that may or may not be controlling your brain at this very instant, is out to get the children. That’s according to a new doom-and-gloom study out of Johns Hopkins University. 

Let’s get this out of the way: T. gondii is an extremely interesting parasite that has been at least casually associated with some not-so-great things. A study last year found that people with the parasite have slower reaction times and are more likely to take risks than people without it. Other studies have casually correlated it with suicidal behavior, depression, OCD, and even brain cancer. 

It is a seriously nasty parasite that develops in rodents, causes those rodents to be mysteriously attracted to cat urine, which is normally where cats hang out, allowing the host rat to be eaten. Once inside the cat, it’s able to reproduce, and its oocytes (eggs) are secreted in cat feces. That’s how you, if you are one of the roughly one third of people estimated to have it, got it. Or you ate some poorly cooked meat. But most people in the United States with toxoplasmosis, as it’s called, get it from cat feces.

But here’s the thing: toxoplasmosis infection is decreasing in the United States and Europe, according to most public health agencies. That might be because we’re cooking our meat better, or better at handling cat poop, or we’re just bad at detecting it. 

Fuller Torrey and Robert Yolken, researchers at Johns Hopkins University, argue that it’s probably the third option. And while toxoplasmosis is definitely not a thing you or your children want to get, their latest paper (published in Trends in Parasitology) would definitely earn dean’s honors at How to Scare the Hell Out of Everyone University. Let’s dissect it.

T. gondii is bad for you: According to the authors, the idea that T. gondii is “largely asymptomatic” in most of the population is a “notion [that] is now under reconsideration.” Concerns include “schizophrenia, depression, suicidal behavior, rheumatoid arthritis, [and] brain cancer.”

T. gondii is bad for your child: It’s been reported before that toxoplasmosis can result in eye problems and other complications for young children. According to the authors, a new concern is “scholastic underachievement in children,” which is bad because…

Cats are everywhere: Between 1989 and 2006, the authors note, the number of pet cats in the United States increased from 54.6 million to 81.7 million. Approximately two thirds of cats sleep with their owners. Remember, most T. gondii infections come from the unwitting ingestion of cat feces.

Which may occur when: a victim is “changing the litter box of a cat, gardening, playing in a sandbox, eating unwashed fruits or vegetables or drinking water containing oocysts.”

Is that all? No. They also note that you can get toxoplasmosis from cockroaches and flies that have come into contact with cat feces and then have hung out with your food. Oh, and “T. gondii oocysts may even infect humans who pet dogs that have rolled in cat feces.”

Toxoplasma oocysts are unkillable: Oocysts, they note, have been able to survive 18 months in soil, two years in super cold seawater, four-and-a-half years in freshwater, and more than a year in a cold sulfuric acid mixture. In fact, most of those studies were aborted after researchers got tired of waiting for the damn things to stop being viable: “Because almost all of these studies were terminated while at least some of the oocysts were still viable, we do not yet know the outer limit of viability for T. gondii.”

But I don’t let my cat outside and I wear a mask and gloves when I change its litter box (Alternatively: “But I don’t have a cat.”): Doesn’t matter. The authors do some very fun calculations involving strays. Twenty-five million stray cats, which is on the low end (some put the number up near 60 million), would create 360,459 tons of feces each year; pet cats add another 900,000ish tons, “resulting in a total accumulation of 1,217,389 tons deposited annually in the environment of the United States.”

They’re targeting your kids: “Because cats do not defecate randomly but rather select places with loose soil so that they can cover their feces gardens, children’s play areas with loose soil, and especially sandboxes (also called sandpits and sand piles) are favored sites.” 

Just to take it a step further, they reference a study done in Japan that calculated the number of T. gondii oocysts in three separate sandboxes. One of them had 1.7 million per square foot; it takes just one to infect a human.

And your kids eat sand: In another, mostly humorous study done at a Massachusetts daycare center, kids “ingested a median of 40 mg of soil per day.” Except for one bright kid who “consumed 5-8 grams of soil per day on average.” Even without the whole eating sand thing, “oocysts are known to become aerosolized when they dry out,it is also possible that a child playing in such a sandbox could become infected simply by breathing in oocysts.”

In case you forgot, cats are everywhere: “There is no historical precedent for such numbers of cats. This should raise public health concerns about the number of T. gondii oocysts being distributed in the environment … as cats increasingly contaminate public areas with T. gondii oocysts it will become progressively more difficult to avoid exposure.”

So how do we fix it? By being scared, all the time: “It should be assumed that the play areas of children, especially sandboxes, are highly infectious …one may become infected by neighboring cats which defecate in one’s garden or play area, or by playing in public areas such as parks or school grounds.”

Oh, we should also kill stray cats: “Prevention can also be accomplished … by educating the public regarding the proper disposal of cat litter, by keeping cats indoors to minimize their acquisition of infection from prey or the environment, and by reducing the feral cat population.”