Is cat-scratch disease linked to schizophrenia? People with the mental health condition are more likely to be infected with Bartonella, a bacteria that can be caught from …

Schizophrenia may be linked to Bartonella, the bacteria behind ‘cat-scratch’ disease which can be caught via bites and scratches from infected felines.

Cats become infected with the bacteria via ticks and fleas, and transmission to humans can cause tiredness, headaches, fever and swollen lymph nodes.

It was long thought that cat-scratch disease was short-lived, but the new findings suggests that in some people the infection may persist.

Researchers from the US tested the blood of both a small number of patients with schizophrenia and healthy adults for evidence of Bartonella DNA.

They found that 12 of the 17 schizophrenia patients had Bartonella DNA in their blood, compared to just a single member of the 13-strong control group.

This preliminary study was very limited in its size and further research will need to be undertaken to establish a definite link between Bartonella and schizophrenia.

However, the findings are suggestive and ‘strongly support’ the launching of follow-up studies, the team commented.

Schizophrenia may be linked to Bartonella, the bacteria behind ‘cat-scratch’ disease which can be caught via bites (pictured) and scratches from infected felines (stock image)

US researchers tested the blood of both a small number of patients with schizophrenia and healthy adults for evidence of Bartonella DNA. Pictured: a hand with scratches from a cat’s claws. Were the cat infected with Bartonella, the person could develop cat-scratch disease

‘Researchers have been looking at the connection between bacterial infection and neuropsychiatric disease for some time,’ said paper 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 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-associated infectious agent, Bartonella, to see if there could be a connection.’

‘While there is emerging understanding of neuropsychiatric illnesses such as schizophrenia as disorders of brain networks, the question about the actual causes remains unanswered,’ said paper author Flavio Frohlich.

‘To our knowledge, this is the very first work that examines a 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 managed cases of schizophrenia or schizoaffective disorder and a control group of 13 healthy adults, all of whom they tested twice in one week for Bartonella infection.

The team found that 12 of the 17 patients with schizophrenia had Bartonella DNA in their blood, as compared to only one member of the control group.

Both the patients and the control groups had reported similar levels of pet ownership and exposure to fleas, which can also carry Bartonella. 

Twelve of the 17 schizophrenia patients had DNA from Bartonella (pictured in this artist’s impression) in their blood — compared to just a single member of the 13-strong control group

‘Bartonella ddPCR, a very new diagnostic technology, provides a more sensitive molecular test than we’ve previously had access to,’ said paper author and infectious disease expert Ed Breitschwerdt of the North Carolina State University.

‘If we had not used ddPCR to test this cohort of individuals, we would not have found Bartonella DNA in any of the participants, either case or control.’

‘It is important to remember that our study was by design not able to demonstrate a causal link between Bartonella infection and schizophrenia,’ said Professor Frohlich.

‘However, we believe this initial observational study strongly supports the need for follow-up research.’

 Cats become infected with the bacteria via ticks and fleas and transmission to humans can cause tiredness, headaches, fever, swollen lymph nodes and lesions at bite sites (pictured)

In fact, with their initial study complete, the researchers are now planning a larger study to see if their preliminary results are indeed borne out

‘Many of these patients have been undergoing care for years. What we’re starting to see is a pattern — Bartonella can persist for a long time,’ said Dr Breitschwerdt.

‘For the subset of people who can’t eliminate the infection, the bacteria can cause chronic or progressive illness.’

The full findings of the study were published in the journal Vector Borne and Zoonotic Diseases.

SCHIZOPHRENIA EXPLAINED

Schizophrenia is a chronic and severe mental disorder that affects how a person thinks, feels, and behaves.

People with schizophrenia may seem like they have lost touch with reality.

The cause of schizophrenia is not understood and it is believed to be a mix of genetics (hereditary), abnormalities in brain chemistry and/or possible viral infections and immune disorders.

Symptoms of schizophrenia usually begin between ages 16 and 30. In rare cases, children have schizophrenia too.

The symptoms of schizophrenia fall into three categories: positive, negative, and cognitive.

Positive symptoms are disturbances that are ‘added’ to the person’s personality and include:

Negative symptoms are capabilities that are ‘lost’ from the person’s personality and include:

Cognitive symptoms are changes in their memory or other aspects of thinking and include:

Figures suggest around one percent of the world population suffers from schizophrenia with around two million in the US.

SOURCE: National Institute of Mental Health

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