Study finds evidence of Bartonella infection in schizophrenia patients

A new study led by University of Wisconsin–Madison School of Veterinary Medicine professor Erin Lashnits shows evidence of Bartonella infection in the blood of people with schizophrenia and schizoaffective disorder.

“Researchers have been looking at the connection between bacterial infection and neuropsychiatric disease for some time,” Lashnits says in a news release by North Carolina State University, where she started her work before coming to the UW.

“Specifically, there has been research suggesting that cat ownership is associated with schizophrenia due to the zoonotic parasite Toxoplasma gondii, but to date there has been no conclusive evidence in support of a causative role for this parasite. So, we decided to look at another cat-transmitted infectious agent, Bartonella, to see if there could be a connection.”

Bartonella are bacteria historically associated with cat-scratch disease, which until recently was thought to be solely a short-lived (or self-limiting) infection. Cats can become infected with Bartonella via exposure to fleas and potentially ticks, which are natural vectors of the bacteria.

Lashnits, who recently joined the UW faculty with expertise in small animal internal medicine, published the study with colleagues on March 15 in the journal Vector-Borne and Zoonotic Diseases.

What causes some neuropsychiatric illnesses such as schizophrenia remains unknown, but researchers are increasingly understanding them to be disorders of brain networks.

The study was, by design, not able to demonstrate a causal link between Bartonella infection and schizophrenia. However, Lashnits believes it supports the need for follow-up studies. The researchers plan to proceed with a larger study to see whether their preliminary results are borne out.

Read more about the study here.