© Anders AnderssonTwo billion people are infected with the Toxoplasma Gondi parasite, most commonly contracted from cats.
Except for a couple of specific circumstances - notably pregnancy - the
world's most common parasite in humans,
Toxoplasma gondii, is thought to induce few symptoms and no serious effects.
However, research from 32 scientists at 16 institutions, linking parasite proteins with small non-coding human RNA molecules known as microRNA, and comparing outcomes for
various diseases between infected and non-infected people, suggests we have severely underestimated the situation.The research,
published in the journal Scientific Reports, implicates
T. gondii in the progress of neurodegenerative diseases, epilepsy, and certain cancers.
Around the world, more than two billion people carry the parasite. The most common route of infection involves one of its primary reservoirs, the domestic cat. Parasite eggs find their way into humans - and many other animals - via contact with cat faeces.
Such contact does not need to be direct.
T. gondii eggs are extremely resilient and can survive dormant for many months in open environments - these frequently include vegetable patches and fields, where cats may defecate into the soil, from which the eggs are transferred to harvested plants.
The parasite, once hatched, lodges in the brain.
Until now, the primary danger recognized for
T. gondii infection was to unborn children. If a woman contracts the parasite shortly before or during pregnancy, the foetus can sustain severe brain or eye damage.
In other cases, though, the infection was thought to be largely asymptomatic, except in around 20% of cases where mild flu-like symptoms are known.
The latest work, led by Rima McLeod of the Toxoplasmosis Centre at the University of Chicago, US, indicates that
infection can seriously affect human health, but in very subtle ways.Using a database comprising details of 246 people who sustained infection in the womb, the team looked for parasite-generated biomarkers and analysed their probable health impact.
The results showed a surprising confluence between certain markers and brain disease. Segments of human microRNA associated with infection, and proteins expressed by the parasite, were found not only in children with severe toxoplasmosis, but also in adults with Parkinson's and Alzheimer's disease.
There was also evidence that
T.gondii proteins interfered with the signaling function of gamma-Aminobutyric acid, which plays in a role in dampening epilepsy.
"We suspect it involves multiple factors," says McLeod.
"At the core is alignment of characteristics of the parasite itself, the genes it expresses in the infected brain, susceptibility genes that could limit the host's ability to prevent infection, and genes that control susceptibility to other diseases present in the human host."
When it infects other species,
T. gondii is known to facilitate its own life cycle by affecting behaviour in its host.
For instance, it causes rats and mice to lose their innate fear of the smell of cat urine, thus placing them in greater danger of being eaten. This process facilitates the transfer of the parasite into a fresh host.
A 2016 study,
published in the journal Current Biology, found a similar effect in chimpanzees. Infection caused them to lose their fear of leopard pee.
In humans,
T.gondii infection has been associated with
less hazardous behavior changes, such as decreased reaction times and loss of concentration.
McLeod and colleagues, however, also found that the parasite altered the function of 12 different types of olfactory receptor in the brain - indicating that it is also capable of driving our own species to dismiss urine-based signals of predator danger.
All up, the research implicated
T. gondii in modifying the functions of 1178 human genes, many of them associated with various cancers.
"This study is a paradigm shifter," says co-author Dennis Steinler at Tufts University. "We now have to insert infectious disease into the equation of neurodegenerative diseases, epilepsy and neural cancers."
Reader Comments
Cat turds cause cancer and brain damage. More like articles and studies like this cause the actual brain damage.
Besides, dogs scarf cat turds like they are chocolates, where are all the diseased mutts?
There were more cats in our street than people so the problem is an overabundance of cats. People get kittens and can't be bothered with them when they are adult animals and less cute, or when they need expensive veterinarian care, so they dump them. Bird populations are destroyed by feral cats. I have seen cats defecate on grass or on the footpath and children's sandpits are very popular with cats. Irresponsible cat owners don't get the males neutered, and they don't care that the females are bred three times a year. Crazy cat ladies are probably infected with the toxo worm and a study should be done on them. It could explain their lunatic behaviour and the fact that they don't seem to notice their homes stink like tomcat spray.
Dogs which eat faeces have a depraved appetite because they are not fed properly.
[Link]
Serious Discussion with Outdoor Cat Owner Neighbor for having their Outdoor Puss-Puss Using Backyard like a Litterbox before calling Animal Control.
Solutions are simple.
Here they have a catch/neuter/release program for feral cats, and they adopt out cats caught that are not feral. But then you have idiots like those in my family that don't fix their pets and think they'll get rich quick selling pit bull puppies and kittens.
Death by Poisoning has always been considered cruel and an aggravating circumstance for sentencing someone to death.
Have you check your psychopathology yet?
You too, Artex: 'Any way possible?" Wow. Where's your dog? Then I can find you - after all, your dog is not the problem with you; you are.
You are malevolents. What are you sick, STS bastards doing here?
R.C.
That is why I've always - as have most worthwhile societies - thought and felt that death by poisoning, which is a long and literally torturous way to kill a living critter* is inappropriate. There are many cruel and unnecessary ways to kill animals and humans, and killing by poison,
seems, nay IS , unnecessarily cruel, and I find it hard to believe that given the choice, anyone would 'choose' to die from ingestion of slow poison, and as such, the anti-freeze 'solution' * is certainly no proper solution. See, generally, the Position statement by the ASPCA at [Link]Instead of slow poison, how about putting out a humane trap, and putting in some fancy feast/expensive cat food for a last meal, and then taking the feline somewhere quiet and then, 'kindly' put a bullet into the base of the critter's skull? Far quicker and less scary on the critter. But tougher on you? Too bad. (And please not in front of other critters... remember Bambi?)**
There are also then some quasi acceptable types of asphyxiation, such as walking into a room full of nitrogen - which is 79% of air - which, with the first breath, takes away oxygen from one's blood, knocking that person out, and then promptly killing them. (This happens about once a decade to humans at space facilities who accidentally walk into 'safe'/non-oxidized rooms filled with nitrogen, where satellites are stored prelaunch.) Also, it's finally logically being approved by some legislatures for capital punishment - as it should be by all of them!
Also, regarding the proposal of 'leaving out' poison, you should realize that Murphy's law will dictate that something like this will result: Your best friend will come unannounced to surprise you and show off their new puppy, let themselves in through your fence gate, relock it, and the dog, then running free, will find and swallow it. That wouldn't happen with a trap. You also wouldn't kill any wandering deer, foxes, squirrels, deer mice, rabbits, raccoons, etc.
Also, even if your only concern is your own laziness, (pure STS - which I don't believe applies to any posters on this), please realize that doing that is a crime in many states, and that might be one of the few things I could think of where even I might call the police.***
R.C.
*Dark pun intended
**Though it's not my personal cup of tea, I'm thoroughly pro-hunting, provided - "you kill it, you eat it."
**Although, like most, I have detested and still detest cockroaches - and long before any MIB movies I wondered whether the almost universal instinctual/innate/visceral loathing of them indicated that they did not arise here in the same fashion as other critters. (And it was likewise long before I ever read Velikovsky, who theorized that some of the plagues of Egypt ('vermin') were extraterrestrially inserted into the earth via a/several near/atmospheric collision(s) with Venus.) And while I only kill them with a flip flop or flyswatter, I always make sure they are not suffering/dying, but are dead - yes, even with loathed cockroaches.
RC
The study itself is very restricted as it only studied:
"Using a database comprising details of 246 people who sustained infection in the womb , the team looked for parasite-generated biomarkers and analysed their probable health impact."
Thus, despite their worldwide quotes of everyone on earth, divide those numbers almost in half (at least insofar as it applies to already-existing humans) as it's irrelevant to males. I.e., they are not the carriers of the parasite that count... women are. This is a gender vectored parasite, though the study doesn't seem to mention that.
Also, the fact that the study conductors stated this:
"McLeod and colleagues, however, also found that the parasite altered the function of 12 different types of olfactory receptor in the brain - indicating that it is also capable of driving our own species to dismiss urine-based signals of predator danger" shows a significant 'scare piece' aspect, designed to get more funding, just like my first point, above.
How many times is a typical American/Westerner even slightly "at risk" from assault by any apex predator animal? We've killed 99.9% of them off.
You have a higher likelihood of getting killed by lightning, and probably of getting bitten by a shark . . . while WALKING ON THE BEACH!
R.C.