Schizophrenia can be linked to Bartonella, the bacterium behind “cat scratch” disease, which can be caught by biting and scratching infected cats.
Cats become infected with bacteria through ticks and ticks and transmission to humans can cause fatigue, headaches, fever and swollen lymph nodes.
Cat scratching was long thought to be short-lived, but new findings suggest that in some people the infection may persist.
U.S. researchers tested the blood of a small number of patients with schizophrenia and healthy adults to detect evidence of Bartonella DNA.
They found that 12 of the 17 patients with schizophrenia had Bartonella DNA in their blood, compared with only one member of the 13-person control group.
This preliminary study was very limited in size and more research will be needed to establish a definitive link between Bartonella and schizophrenia.
However, the findings are suggestive and “strongly support” the launch of follow-up studies, the team commented.
Schizophrenia can be linked to Bartonella, the bacterium behind “cat scratch” disease that can be caught by bites (pictured) and scratches of infected cats (stock image)
U.S. researchers tested the blood of a small number of patients with schizophrenia and healthy adults to detect evidence of Bartonella’s DNA. In the picture: a hand with scratches from a cat’s claws. If the cat was infected with Bartonella, the person could develop a disease to scratch the cat
“Researchers have been studying the connection between bacterial infection and neuropsychiatric disease for some time,” said the paper’s author and veterinary researcher Erin Lashnits of the University of Wisconsin.
“Specifically, there has been research suggesting that cat ownership is associated with schizophrenia due to the zoonotic parasite Toxoplasma gondii, but so far there has been no conclusive evidence to support a causative role of this parasite.
“So we decided to look at another infectious agent associated with a cat, Bartonella, to see if there could be a connection.”
“While there is an emerging understanding of neuropsychiatric diseases such as schizophrenia as brain network disorders, the question of the real causes remains unanswered,” said Flavio Frohlich, author of the paper.
“To our knowledge, this is the first work examining the potential role of Bartonella in schizophrenia,” the University of North Carolina psychiatrist added.
In their small-scale study, the team enrolled 17 people with stable and medically controlled cases of schizophrenia or schizoaffective disorder and a control group of 13 healthy adults, who tested Bartonella infection twice a week.
The team found that 12 of the 17 patients with schizophrenia had Bartonella DNA in their blood, compared with only one member of the control group.
Both patients and control groups reported similar levels of flea ownership and exposure, which may also lead to Bartonella.
Twelve of the 17 patients with schizophrenia had Bartonella DNA in their blood (shown in this artist’s image), compared with only one member of the 13-person control group.
“Bartonella ddPCR, a very new diagnostic technology, provides a more sensitive molecular test than we’ve had access to before,” said Ed Breitschwerdt, author of the article and an infectious disease expert at North Carolina State University.
“If we had not used ddPCR to test this cohort of individuals, we would not have found Bartonella’s DNA in any of the participants, either in case or in control.”
“It is important to remember that our study was not able to demonstrate a causal link between Bartonella infection and schizophrenia,” Professor Frohlich said.
“However, we believe this initial observational study strongly supports the need for follow-up research.”
Cats become infected with bacteria through ticks and fleas and transmission to humans can cause fatigue, headaches, fever, swollen lymph nodes and injuries at bite sites (pictured)
In fact, with their initial study completed, researchers are now planning a larger study to see if their preliminary results are really confirmed.
“Many of these patients have been cared for for years. What we are beginning to see is a pattern: Bartonella can persist for a long time,” Dr. Breitschwerdt said.
“For the subset of people who cannot eliminate the infection, bacteria can cause chronic or progressive disease.”
The full findings of the study were published in the journal Vector Borne and Zoonotic Diseases.