Cats are extremely cute and friendly animals. They are known for their independence and loyalty. Many people keep cats as pets in their homes. But is it really safe to own cats?
A new study reveals that Toxoplasma gondii, an infectious parasite hosted by cats, can subject people to take high risks in their lives and hence can show behavioral changes. Cats are the definitive hosts, and this parasite can reproduce sexually only in the intestines of cats, but it can multiply in other hosts. As a result of sexual reproduction, oocytes are formed and released through the cat's feces.
Following are the possible ways humans get infected with Toxoplasma gondii:
ingestion of contaminated food and water
ingestion of uncooked meat
drinking unpasteurized goat milk
cleaning cat's litter
playing in mud or sand
Most people with toxoplasmosis are unaware that they are carrying the infection because they do not show any symptoms, and some may have flu-like symptoms and not require treatment. But people with weakened immune systems do require drug therapy. Toxoplasmosis can be life-threatening to the unborn child if the pregnant mother gets infected. This is known as congenital toxoplasmosis, and it can cause severe birth defects. Hence, pregnant women are advised not to clean cat litter and to stay away from stray cats.
A recent study shows that people with toxoplasmosis exhibit some behavioral changes and are more likely to take high risks in their lives. Some people who have contracted the infection were found to be very active in risky business ventures and related fields.
Studies also found that mental disorders like schizophrenia, anxiety, and depression are common in people with toxoplasmosis. Toxoplasma gondii can rewire the brain permanently by forming cysts inside human neurons.
People with HIV or a weakened immune system are at high risk, as these cysts can replicate and cause infections in the brain that may lead to psychosis, dementia, and other neurological disorders.
We, humans, like to think that our thoughts are autonomous and self-driven. But contrary to this belief, many studies suggest that many variants of bacteria and viruses can influence our thought process. For example, gut bacteria has been found to be associated with anxiety and depression and can regulate serotonin, a happy hormone.
Toxoplasma gondii is associated with alterations in human behavior. Greater seroprevalence of toxoplasma has been found in many patients suffering from schizophrenia, depression, and bipolar disorders."Dr. Malabika Biswas, MBBS, MD Microbiology
What could be the science behind it?
Researchers are trying to find a link between cat parasites and human behavioral changes. Well, Toxoplasma can penetrate the host's brain and make some changes in brain chemistry.
As a result, the host's fear and anger emotions are manipulated, which implies that Toxoplasma can control a rodent's mind to some extent. For instance, rats infected with Toxoplasma gondii lose their fear of cats and are more attracted to their scent and urine, which makes them easy prey.
The cat eats the infected rat and sheds more parasites in their feces, which are consumed by another rat, and this cycle continues. In this manner, the parasite ensures its survival and propagation.
When it comes to humans, it generates almost the same mechanism in our brains that reduces our fear of failure, which in turn makes us take high risks. So, do these cat parasites have the power to control humans' minds as well?
Many hypotheses and assumptions about toxoplasmosis are yet to be proven. Can Toxoplasma gondii make hosts love felines?
As rodents are the most common hosts, the parasite wants them to get attracted to cats in order to continue their life cycle and propagation. But what if similar manipulation happens in human brains too? Yes, some researchers are trying to find out whether cat lovers are infected with toxoplasma and why people with toxoplasmosis often end up with many pet cats in their homes.
So, is it safe to keep cats? The answer is 'yes'. These cute felines are not the only cause of toxoplasmosis. The majority of people get infected due to the consumption of undercooked meat. So, it is harmless to keep cats if you take proper care while cleaning their litter. It is also advised not to send your cats outdoors to prevent them from contracting this infection.
Now the question is, should we fear if we get infected with Toxoplasma gondii?
The human species has been living for many centuries with Toxoplasma gondii, as samples of this parasite have been found in ancient Egyptian mummies.
Even if we do carry this parasite, the chances of developing schizophrenia and other mental disorders are very low.