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LiveScienceWomen infected with the cat parasite Toxoplasma gondii are more likely to attempt suicide than non-infected women, new research finds. The reason for this connection, however, remains mysterious.
T. gondii is a protozoa that prefers to infect cats, but can make its home in any warm-blooded animal. Humans can pick up the parasite from contact with cat feces, or by eating undercooked meat or unwashed vegetables. Once ingested, T. gondii can make a home for itself inside the brain and muscle tissues, protected inside cysts that are resistant to attacks by the host's immune system.Some studies have linked infection by this parasite with a variety of mental health and brain problems, including schizophrenia, neurosis and brain cancer. But scientists aren't clear on whether the parasite contributes to these problems or is a mere side effect. Someone with schizophrenia, for example, might struggle to keep up good hygiene, meaning the mental disorder could increase the risk for infection. [ Top 10 Diabolical & Disgusting Parasites ]
The new study linking suicide and T. gondii has the same limitation. Researchers can't say for sure whether the parasite somehow drives people to suicide. But in women with infections, they found, the risk of an attempt is 1.5 times greater than in women without.
"We can't say with certainty that T. gondii caused the women to try to kill themselves, but we did find a predictive association between the infection and suicide attempts later in life that warrants additional studies," lead researcher Teodor Postolache, a psychiatrist at the University of Maryland School of Medicine, said in a statement. "We plan to continue our research into this possible connection."
A common infection
One-third of the world's population is infected with T. gondii, which is often asymptomatic. The parasite is the reason that pregnant women are advised not to change cat litter boxes — they can inadvertently pass an infection directly to their fetuses.
In its usual animal hosts, T. gondii plays a literal cat-and-mouse game. Mice infected with the parasite lose their fear of the smell of cat urine. The parasite actually changes the brain so that the cat-pee smell becomes sexy to mice, prompting them to get close to their adversaries. This works out well for the parasite, which needs to get to a cat intestine to reproduce.
It's unclear whether the parasite's mind-control techniques have any effect on infected humans. Spurred by a couple of small studies of mentally ill patients that found links between suicide and T. gondii,Postolache and his colleagues put together a massive research project on 45,788 Danish women whose newborns had been screened for T. gondii antibodies between 1992 and 1995 (a positive result was a sure sign that mom was infected). About a quarter of the women had been infected at the time of delivery, the results revealed.
The researchers then combed through all of the women's later medical records for suicide attempts. They found a relatively small number, 517, had tried to kill themselves, with 78 of these women attempting violent methods such as guns, sharp instruments or jumping. Eighteen women in the sample succeeded at killing themselves, eight of whom had T. gondii infections.
A statistical analysis turned up a link between suicide attempts and parasite infection, such that an increasing number of T. gondii antibodies were linked with an increasing risk of attempts, especially violent attempts. When looking at just attempted suicides, researchers found women who were infected were 1.8 times more likely to attempt suicide by violent means than uninfected women.
The researchers were able to control for diagnoses of mental illness, meaning that infection was independently linked to suicide attempts, not just to mental health problems in general.
Suicide and parasites
More study will be needed to determine if the parasite somehow causes suicide attempts or self-harm, Postolache said.
"T. gondii infection is likely not a random event, and it is conceivable that the results could be alternatively explained by people with psychiatric disturbances having a higher risk of becoming T. gondii infected prior to contact with the health system," he said.
If the parasite is found to be a cause, the next mystery to unravel will be how, Postolache said. It could be that the parasite acts directly on the brain in a way that promotes mental illness. Or perhaps it triggers the immune system to attack the brain somehow. Either way, he said, infection by T. gondii isn't necessarily a mark of doom. For one thing, even with a 26 percent infection rate, the number of women in the study who attempted suicide was very small. For those who may be at risk, there may be treatments.
"If we can identify a causal relationship, we may be able to predict those at increased risk for attempting suicide and find ways to intervene," Postolache said.
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*PLEASE remove this story or, AT A MINIMUM, change the headline and title photo.
This may sound amusing at first glance but, should not be taken lightly. These reports have serious negative implications for cats who are already abandoned by the thousands every day . This headline is very simplistic and not even what the study actually looked at. This is irresponsible reporting, in my opinion, and contributes to the myths and misconceptions that cause people - particularly families with small kids - to give up their pets and/or not adopt needy cats.
Thank you!
Thousands is right. Just one L.A. shelter kills an average of 1000 animals per week.
....Crock science at it's best. 11,000+ women also had the parasite and made no attempt at suicide. That does not even approach a correlation.
We come in peace really, just pet the nice kitty and take him into your home.
Years ago, Discover Magazine published a blurb about research done on mice that showed that mice (or maybe it was rats, I don't remember) infected with T. gondii would actually SEEK OUT cats to eat them. The research indicated that this particular parasite caused the mice to do this because T. gondii completes it's lifecycle in the gut of cats. It was an amazing study. Basically the research showed that T. gondii infection caused suicidal tendancies in mice/rats. Why are these researchers having a hard time making the "suicidal tendancies" connection between the rats and humans? Both are mammals. And mice/rats are used in all sorts of scientific studies as a "guinea pig" of sorts in place of humans. If T. gondii can make rodents suicidal, why not humans? Therefore, my next question would be: Are these women infected with T. gondii seeking out suicide via cat? However, I'm sure that will raise some hackles among those here with no sense of warped humor, so I offer my apologies in advance...
From wikipedia:
"T. gondii infections have the ability to change the behavior of rats and mice, making them drawn to,
rather than fearful of, the scent of cats. This effect is advantageous to the parasite, which will be able to sexually reproduce if its host is eaten by a cat.[12] The infection is widespread in the brain, with more cysts targeting the parts of the brain corresponding to fear. The widespread nature of the infection causes
many previously unnoticed symptoms in the rats.[13]"
#23.1
Beluga22That reminds me of some Humans that take up dangerous sports, could be that they have that Parasite!? lol
( Laughter is the Best Medicine )
years ago, when in my child-bearing years, I was sure I must have contracted this disease from one of the dozens of cats I had lived with all my life. But I tested negative, and 3 of the 4 cats I owned at the time tested positive. That's when I found out that once cats have the antibodies, and they usually get them while still kittens, they no longer shed the infective oocysts. Contacting the research lab at the Cornell University College of Veterinary Medicine we were told that even cats with very low titres don't shed the oocysts. Catching this disease from cats is, apparently, rare. My understanding was, and still is, that this disease is contracted from handling and eating undercooked meat.
#24 -
With all due respect " Carriers " do not show the symptoms and hence cannot be detected but they still can infect others!!
Good article, and a Warning to all with a working brain cell, a few years with the " Monkey Virus " outbreak, it was pointed out that the carriers where actually NOT Monkeys surprise surprise but Cats and Dogs, so it seems that Humans are Prone to many ailments from their " Pets " and hence should be informed!
Since no real correlation seems to be existing, it can in turn be also stated that Humans are prone to many ailments from Humans.
#25.1
No Correlation? I must be reading " Special Articles " so H1N1 Malaria and a host of others are " figments " Wow! thanks for the insight, did you read about the " Monkey Virus "?
This is the most irresponsible thing I've read. Shame on MSNBC. Any veterinarian can test your cat for toxoplasmosis, if your cat is negative then no worries. Also, it takes 48 hours after the cat defecates in the litter box for the toxo parasite to get infective, so if you're cleaning the litter box regularly then no worries! Just practice good hygiene: keep the litter box clean, wash your hands, and no one is at risk. Good lord I hope no cats are tossed out of their homes because of this irresponsible misinformation.
Since eating cats seems to be sanctioned in Asia, it seems to me that this article is disinformative.
In the meantime, the World Health Organization is silent about the burgeoning cat and dog fur and meat market in Asia.
You should try "pate' du chat-merde". It's lovely on a water cracker with a sprig of cilantro ...
I have never owned a cat, but I have Toxoplasmosis in my right eye. When active the parasite causes spots in my vision. Also minor pain. It is kept under control with a steroid — prednisone. I am a 51 year old male. I got the parasite working as an electrician, when I was 23. You would not believe how many cats go under a house in a dirty crawlspace to die. It is attached to my retna. The steroid is injected directly into the eye. The only way to kill it is kill it's host. Blindness is possible, but I had rather the host stay alive. It's something you deal with and keep going. I can't say what it would be like in the brain or a pregnant lady. Yes men You do change litter boxes, but you are not tested the same as a pregnant woman. I wouldn't know I have it if it were somewhere beside in my eye. Plenty of men have it and will never know it or have any symptoms at all. Yes it does exist.
Susan, that's because cats don't really care about you. You're a meal ticket, nothing more.
Here's an experiment: Lock your husband and your dog in the trunk for four hours. See who is happy to see you when you open it up. That is the one that offers unconditional love.
" unconditional Love " is more akin to a blind date, does one really need to make self blind to know what it feels like?
This is just more evidence that we should start asking, "Which came first - the crazy or the cat?"
#31 -
Amanda, I , will respond to you with,logic, but I fear that would create a problem, but here we go.
In a previous thread some one brought up " chicken or egg " and hence I said " Chicken " for a numnber of reasons, 1) Ova,Body heat,Hatching. 2)Productivity,odds, most likely
To which I was told " I stopped reading just after i read what You said about Chicken first " lol
and the respondent said " Obviously the " Zygote " came first ,lol, So for what you said if the " Cat was not first how could the parasite without a host be pressent to infect? lol Just IMHO