ADULT psychosis has been linked to the blood-borne Bartonella species. Bartonella species are most often transmitted by arthropod vectors or animal bites and scratches. Infected individuals can experience cardiovascular, rheumatological, and neurological symptoms, including neuropathy, seizures, and encephalitis, and now evidence points towards neuropsychiatric symptoms.
Previous research identified that people with schizophrenia or schizoaffective disorder were significantly more likely to have Bartonella species DNA in their blood than healthy controls. In a follow-up study, the researchers investigated whether Bartonella species exposure or infection is associated with psychosis.
Researchers investigated the presence of Bartonella species in a cohort of 116 participants (44 adults with psychosis, 7 children or adolescents with psychosis, 16 prodromal participants, 20 relatives of a participant with psychosis, and 29 healthy controls). Researchers investigated Bartonella species exposure by identifying the presence of anti-Bartonella antibodies using indirect immunofluorescence assays. Rates of infection were determined by amplification of bacterial DNA from blood by quantitative polymerase chain reaction, digital PCR, and droplet digital PCR in participants.
The results demonstrated that 43.2% of adults with psychosis had Bartonella species DNA in their blood, compared to only 14.3% of controls (p=0.021). The results of quantitative polymerase chain reaction, digital PCR, and droplet digital PCR testing revealed that DNA from at least one Bartonella species was amplified in 26.7% of participants, and the difference in the proportion of PCR-positive adults was statistically significant between the control group (14.3%) and the group with psychosis (43.2%; p=0.021). Analysis revealed that B. henselae was the most frequent species amplified from blood. The researchers found that there was no significant difference in Bartonella species seroreactivity between groups, and that immunofluorescence assay sensitivity was low. These results suggest that serological tests are not clinically useful in this context.
This study showcases that adults with psychosis are more likely to have Bartonella species DNA in their bloodstream, highlighting a link between this bacterial species and psychosis. Further research should aim to elucidate these findings and investigate the potential links between other microbial infections and neuropsychiatric disorders.
Katrina Thornber, EMJ
Reference
Delaney S, et al. Bartonella species bacteremia in association with adult psychosis. Front Psychiatry. 2024;15:1388442.
