Toxoplasma gondii infection not linked with aggression among prisoners

A new study revealed that Toxoplasma gondii infections are not associated with violent behaviors of prison inmates. The study results were published in the journal PLOS ONE. 

T. gondii is a protozoan parasite causing infections in humans and animals. It resides in latent form in the central nervous system and is associated with the incidence of specific neuropsychiatric conditions in humans like generalized anxiety disorder, mixed anxiety and depressive disorder, bipolar disorder, obsessive-compulsive disorder, schizophrenia, and depression. Literature shows that T.gondii infection may cause nonfatal suicidal self-directed violence, aggression, and impulsivity. As there is uncertainty on the incidence of T. gondii infection and violent behavior, researchers from Mexico conducted a study to evaluate the association between T. gondii seropositivity and violent behavior in a sample of inmates in the northern Mexican city of Durango. 

128 convicts (mean age: 35.89 10.51; range: 19-65 years) were evaluated in a cross-sectional research design. Participants' sera were tested for anti-T. gondii IgG antibodies using an enzyme-linked immunosorbent assay. The historical, clinical, and risk management-20 (HCR-20) tool, the kind of offense for which offenders were convicted, and the Buss-Perry Aggression Questionnaire were used to measure violence. (AGQ).

Key findings: 

• Of the 128 inmates, 17 (13.3%) had a high risk of violence by the HCR-20 criteria, 72 (56.3%) were considered violent by the type of crime committed, and 59 (46.1%) were considered violent by the AGQ.
• Depending on the violence evaluation method, the seroprevalence of T. gondii infection in violent inmates varied from 0% to 6.9%.
• There was no statistically significant difference in anti-T. gondii IgG seroprevalence between violent and non-violent inmates. 
• Mean scores of the AGQ were similar in both the T. gondii seropositive inmates and T. gondii seronegative inmates (P = 0.55).
• Mean scores of anger, psychical aggression, verbal aggression, and hostility in T. gondii seropositive inmates were similar to those found in T. gondii seronegative inmates. 

Thus, using three types of evaluations of violence revealed that seropositivity to T. gondii is not associated with violence in inmates in Durango, Mexico. 

Further reading: Rocha-Salais A, Muñoz-Larreta FY, García-Pérez SI, et al. Survey on the association between Toxoplasma gondii infection and violent behavior in inmates. PLoS One. 2023;18(4):e0284202. Published 2023 Apr 7. doi: 10.1371/journal.pone.0284202