Does Parasite Play Role in Schizophrenia Etiology?

New Book: Eyes Wide Shut: An Enigma

Hide In Plain Sight
Hide In Plain Sight | Source
 T. gondii can infect the eyes and brain, often resulting in blindness and severe neurological disease. Neurological damage (encephalitis) occurs in children who contract the infection congenitally and in compromised individuals.
T. gondii can infect the eyes and brain, often resulting in blindness and severe neurological disease. Neurological damage (encephalitis) occurs in children who contract the infection congenitally and in compromised individuals.

Does Parasite Play Role in Schizophrenia Etiology?

There is growing evidence that the parasite Toxoplasma gondii is implicated in certain cases of schizophrenia. First the evidence came from prenatal blood samples. Now it comes from young people developing symptoms of schizophrenia.

Toxoplasma gondii

T gondii is a protozoan parasite whose definitive host is the cat family. Humans become infected by ingesting oocysts (eggs) shed in the feces of infected cats or by eating undercooked meat from an animal that came into contact with infected cat feces. T gondii is one of the most widespread human parasites; 10% to 20% of Americans test seropositive by adulthood. Exposure to T gondii during early pregnancy can cause severe fetal CNS abnormalities. Exposure during late pregnancy was never considered a problem until recently, when animal data showed that late exposure to the organism causes behavioral changes, neurologic symptoms, and stillbirths.

Since 1956, more than 20 studies have compared antibodies to T gondii in adults with and without schizophrenia. An overall analysis of the studies indicates that serologic evidence of Toxoplasma infection is almost 3 times more common in persons with schizophrenia than in controls living in the same geographic region. Two additional studies reported an increased level of T gondii antibodies in the late-pregnancy serum of women giving birth to infants in whom schizophrenia later developed. Other studies have reported greater childhood exposure to cats among persons with schizophrenia than among controls. Research is focusing on the timing of Toxoplasma infections in relation to development, as well as on possible differences in T gondii strains and human genetic susceptibility.

Numerous studies indicate that, although the symptoms of schizophrenia generally do not manifest until late adolescence or early adulthood, the disease process has its origins in earlier stages of brain development. The ability of Toxoplasma organisms to infect the perinatal brain is thus consistent with this aspect of schizophrenia pathogenesis. However, prospective studies also support a possible role of postnatal infections in some cases of schizophrenia. The potential effects of the transmission of Toxoplasma in early childhood or later in life should be considered.

Epidemiologically, two studies have reported that adults who have schizophrenia or bipolar disorder had a greater exposure to cats in childhood.

More by this Author


Comments 9 comments

Nellieanna profile image

Nellieanna 6 years ago from TEXAS

I do hope that by the time one is into late 70s, has had cats over long periods of those years and has exhibitted no bipolar disorder or schizophrenia, tht the danger zone is well past! ;-) (hope that being a littlee aquirrelly isn't symptomatic, though.

I do hope that by the time one is into late 70s, has had cats over long periods of those years and has exhibitted no bipolar disorder or schizophrenia, tht the danger zone is well past! ;-) (hope that being a littlee aquirrelly isn't symptomatic, though. See my hub http://hubpages.com/animals/Paranoid-Or-Just-Plain...


always exploring profile image

always exploring 6 years ago from Southern Illinois

wow, something to think about., thank,s for the info.


dallas93444 profile image

dallas93444 6 years ago from Bakersfield, CA Author

Nellieanna, Your have no fears... Cats R Us....


Nellieanna profile image

Nellieanna 6 years ago from TEXAS

Dallas - I didn't really feel any fear. Thank you for reassuring me anyway!


dallas93444 profile image

dallas93444 6 years ago from Bakersfield, CA Author

always exploring

My comments to you:

Knowledge is power! I like cats. My intent is simply to share what I discovered in the process of doing research for my fiction book (Eyes Wide Shut: An Enigma) based upon actual events.


Angela Harris profile image

Angela Harris 6 years ago from Around the USA

I had heard about this. It is why pregnant women should leave cleaning the litter box to someone else. This really needs to be made more common knowledge. Hopefully, ob-gyns are warning their patients. Very useful and important information.


dallas93444 profile image

dallas93444 6 years ago from Bakersfield, CA Author

Angela Harris, I agree. The Central Valley in California is dumping treated sewage into the Central Valley Water Project, which does not eradicate Toxoplosmosis (T. gondii) and 23 million people drink from this...

Morro Bay, a Mid-Coast beach town dumps their sewage 3 miles off shore and has the highest dead seal count in California. Seals are like canaries the miners used to monitor if the air was good. All warm blooded aquatic animals in the ocean are infected... There is no cure.


Pamela Kinnaird W profile image

Pamela Kinnaird W 6 years ago from Maui and Arizona

This is very interesting. Sad and alarming -- if it turns out this is the culprit. There are so many theories out there on schizophrenia. This article is good because it motivates one (if the subject is dear to one's heart for any reason) to do further research on the possible culprit, Toxoplasma gondii, and the alleged studies. I'd never heard of T gondii. Good article.


dallas93444 profile image

dallas93444 6 years ago from Bakersfield, CA Author

Pamela Kinnaird W, I am standing on a soap box, roof toop and yelling as loud as I can, "Houston, we have problem..."

Examples: (I have hub pages discussing in more details)

Cities in the San Joaquin Valley in Central California are dumping treated sewage into the Central Valley Canal where the Los Angels area over 23 million people drink T. gondii parasites. There is no cure. In addition, Morro Bay, located in mid-coast, California is dumping treated sewage three miles offshore. The seals are dying in record numbers in this area. All are infected... Treated sewage process does not eradicate Toxosplasmosis (T. gondii).

I live in Pismo Beach, Ca, On the pier is a notice, "400 pigeons live here. 25 lbs of pigeon waste daily are deposited here. Do not feed the pigeons. The pigeons spread T. gondii. Pismo Beach has the worst polluted beach in California. It is a combination of the pigeons and a polluted stream that also dumps T. gondii into the ocean.

    Sign in or sign up and post using a HubPages Network account.

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.


    Click to Rate This Article
    working