A new study has found that one of our most lovable pets — house cats — may carry a parasite that has been linked to mental illness, and it’s a disease that can be passed on to humans.

The paraside, dubbed Toxoplasma gondii (T. gondii), may be present in 60 million people in the United States, estimates the Centers for Disease Control and Prevention as reported by CBS News.

For most people, the parasite doesn’t cause any system, but for those with an immune system that has been weakened, T. gondii can result in toxoplasmosis, which leads to fetal development disorders, a flu-like illness, blindness, or even death. Also, it has been associated with mental disorders, which can include schizophrenia or bipolar disorder.

A study by researchers at the Stanley Medical Research Institute and the Stanley Laboratory of Development Neurovirology at the Johns Hopkins University School of Medicine delves into the link between T. gondii and schizophrenia. The latest study compares previous studies that found a link between having a cat as a child and the later development of schizophrenia, suggesting that being exposed to cats as a child led to a greater incidence of development mental disorders.

Their research indicated that those who were infected with T. gondii were almost twice as likely to develop schizophrenia.

There are an estimated 75 to 80 million pet cats plus another approximately 30 to 40 million strays in the United States, and scientists believe that outdoor cats are more likely to carry T. gondii.

What can you do to reduce your risk if you have a cat, especially if you have children? Keep your cat indoors and cover the sandbox when it isn’t in use. Also, change your cat’s litter box every day, since it takes at least a day and sometimes up to five days for T. gondii to become infectious. And don’t feed cats raw meat.

Pregnant women should avoid cleaning litter boxes and toxoplasmosis is very hazardous for unborn children.