Toxoplasmosis, Anyone?

In one of the many books I’ve read on lupus, it suggested that lupus patients are more susceptible to toxoplasmosis (a disease mainly contracted through cat litter/feces).

I wonder if anyone knows more about this. Is the susceptibility increased because of an already compromised immune system or is there something inherent in the bacteria, itself, that increases susceptibility?

I’ve been considering getting a cat, but wasn’t sure if it was a good idea because of my various health issues. After reading the warning from the book, I am definitely not sure if it is a good idea, but I would like to find a better explanation of why this occurs.