Monday, March 7, 2016

Toxoplasmosis gandii: schizophrenia, bipolar disorder and cancer

Toxoplasmosis gandii is a single celled parasitic protozoan which is an obligate intracellular parasite. It can infect warmblood animals. Felids are their primary host which allow them to sexually reproduce. It’s the most common parasite in countries which are still developing. This means that 30-50% of people throughout the world are infected, many of them chronically. In fact, 84% of the people in France are infected with this parasite. It has been shown that it has an effect on the brains of rats, and now they find it may affect humans as schizophrenia. It may affect humans in similar ways it affects rats. It goes through several life cycles:  Tachyzoites (multiply in a host), merozoites (multiply in a felid for sexual reproduction), bradyzoites (slow division into cysts) and sporozoites (within occysts). Exposure to felids, felid waste, felid waste in food, substrate, contaminated soil and more may get an animal sick, and a human as well!

By far my interest in is Toxoplasmosis gandii. This is primarily because I grew up with cats and despite the fact that most people do not test for this it  could be in a large population. It can be spread in contaminated food/meat, contaminated water, contaminated soil and it can be spread in feces. It operates in an interesting way and its effects are fascinating if not a little horrifying. Despite its effects on humans, many people don’t know about it. It is interesting that the younger/teenage group is what showed evidence of schizophrenia correlating with toxoplasmosis gandii antibodies being currently present and being around cats, and it had a lower appearance among adults in a 30 study review. In that same study though, half of the people showed a correlation to the parasite antibodies and to the current presence of cats.

I found the time of exposure to be of particular interest. Such as seeing the effects of congenital infection of the Zika Virus to be an indication of the effects of viruses and other pathogens on unborn children. Would this early exposure time, such as while still in the mother have an effect like this? We know that toxoplasmosis gandii can cause problems in pregnancies, in addition, its effects on post birth conditions and some other early conditions are documented in many kinds of animals. Scizophrenia is interesting, in that for some it may show up in someones 20’s, is  this an indication of infective age? Does this imply that some effects from a disease may take a certain amount of time for the parasite’s effects to show in a host, or is it only then that it manifests and it  could have been present in a host?

Learning that feral and neighborhood domestic cats use public sandboxes to defecate in may spread the disease. Worse of all, will it deliver the disease at a time which will effect children at a vitally developmental age for the brain. As we learn that the first five years are integral to brain development, does this give an indication of when some early brain issues could begin due to exposure? Surely this is supported by some of the potential findings. This is that early childhood exposure to cats is more likely to be a problem than adult ownership of cats. Are their early signs? I have several friends who are schizophrenic, and I know they all have early exposure to cats. Of course, cats are a common pet. Most people do not have them tested to see if they have toxoplasmosis gandii.

According to E. Fuller Torrey, Cats carring the parasite may risk infecting people with this parasite which he believes may be responsible for some cases of schizophrenia and bipolar disorder.

Although they have a lifetime approved live vaccine for sheep called Toxovax (MSD Animal Health), there is no human vaccine. We countinue to see what effects it has, and it has been documented as giving issues to young children. IT can be passed congenitally, and has been well documented in sheep and rodents. The parasite was found in a cesarean section infant girl showing with seizures and  lesions. There are 17 known species of felids which can spread oocytes and they are the only creatures that can spread this way. According to some behavioral studies, it is found that it affects men and women differently when measured with the Cattell’s Personality Factor Questionnaire. In people who are immunocompromised, they may be vulnerable to Toxoplasmosis Gandii. In addition, if they become ill, it may reactivate tissue cysts, re-releasing the parasite once held at bay by a stronger immune system. As the immune system declines, the parasite reproduces and puts the individual at more risk. Or could it be the other way around?

There are some interesting correlations between brain cancer rates and toxoplasmosis gandii. In fact, the countries that are highest in toxoplasmosis gandii, are also highest in brain cancer rates, at 1.8 times more likely in the 37 countries studied, according to Discover magazine. This may be due to sanitization techniques, other illnesses, natural reproduction of pathogens, distribution of pathogens and vectors, the medical services available to people, as well as the technology available. Although this tells us there may be a correlation, we may not know what that is yet. However, since the parasite is known to affect the brain, it is something to consider.

Since the parasite prevents the cells from killing each other, and it also creates mild inflammation these are both hallmarks of cancer. This means it is potentially involved in the development for brain cancers. The parasite lives a long time in the brain, and it takes a long time for brain tumors to develop. American researchers found the most common glioma brain cancer, astrocytoma is very likely to have the parasite. This is contraindicative of Australian findings where they found the brain parasite meningioma is likely to have a link to the parasite.

Could it be subgroups of the parasite which are more likely to cause certain cancers depending on the parasite strain? Could certain parasites be prevalent in some regions rather than others? There are many infections known to cause cancer…is this another one? The EBV virus causes lymphomas, and HPV and Epstien Barr are also known to cause cancer. The problem with finding this correlation, is that it is expensive and difficult to prove with some information countering findings. Additionally there are about 120 types of brain cancers. There’s nothing yet to support these findings though, and they haven’t had much study.

For the most part, people who own cats are not more likely to have brain cancer. It comes from sources other than cats however, which makes the parasite difficult to trace. In fact, some studies show it may influence the destruction of some cancer. It stimulates cytotoxic T cells, used by the body to fight cancer (is that a sign on its own). This helps the body fight other cancers. CPS a Mutant version developed to fight cancer has promising results in animal trials and it cannot reproduce on its own.

“Avoiding Childhood Exposure to Cats with the the T. Gondi parasite may reduce schizophrenia risk” schizophrenia.com http://www.schizophrenia.com/prevention/cats.html

Pet Theory. Do Cats Cause Schizophrenia? by Stephen Mihm. The New York Times Magazine on the Web. http://www.schizophrenia.com/research/schizovirus.htm

Toxoplasmosis Gandii. Wikipedia. https://en.wikipedia.org/wiki/Toxoplasma_gondii

A Report of Two Cases of Cerebral Toxoplasmosis in Leukemia Patients. http://jjmicrobiol.com/8906.fulltext

Is the parasite Toxoplasma gondii linked to brain cancer?
By Ed Yong | July 26, 2011
http://blogs.discovermagazine.com/notrocketscience/2011/07/26/is-the-parasite-toxoplasma-gondii-linked-to-brain-cancer/#.Vt5HjvkrJD8

Good News: Your Cat Won't Give You Brain Cancer. Live Science.
by Stephanie Pappas, Live Science Contributor   |   August 21, 2012 07:01pm ET

Could cat feces help cure cancer? Written by Honor Whiteman. Published: Sunday 20 July 2014. http://www.medicalnewstoday.com/articles/279776.php

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