Driving us mad: the association of Toxoplasma gondii with suicide attempts and traffic accidents - a systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational (cohort/case-control) studies
PubMed 31010440 · doi:10.1017/S0033291719000813
What was done
A systematic review and random-effects meta-analysis following PRISMA guidelines was conducted across Medline, PubMed, and PsycINFO up to February 11, 2019 (PROSPERO CRD42018090206). The authors evaluated the association between serological markers of latent *Toxoplasma gondii* infection and unnatural outcomes: traffic accidents (TA) and suicide attempts (SA). Sensitivity analyses, publication bias assessments, and population attributable fractions (PAF) were calculated.
What was found
Seropositivity for *T. gondii* antibodies was significantly associated with traffic accidents (OR = 1.69; 95% CI 1.20–2.38, p = 0.003) and suicide attempts (OR = 1.39; 95% CI 1.10–1.76, p = 0.006). For traffic accidents, effect sizes increased with higher antibody titres, and adjusting for detected publication bias did not alter the OR. For suicide attempts, heterogeneity was explained by control selection (OR vs. healthy controls = 1.9, p < 0.001 vs. OR vs. psychiatric controls = 1.06, p = 0.87) and diagnostic group (OR in schizophrenia = 0.87, p = 0.62 vs. OR in mixed populations = 1.8, p < 0.001). The estimated PAF was 17% for traffic accidents and 10% for suicide attempts.
Why it matters
Latent toxoplasmosis is widespread and these findings link infection to elevated risks of traumatic events and self-harm, indicating a potential target for public health prevention if causality is established.
Limits
The abstract does not disclose the total number of included studies or participant count. The underlying studies are observational and susceptible to residual confounding, precluding causal inference. Furthermore, publication bias was noted for traffic accidents, and the association with suicide attempts disappeared when comparing cases to psychiatric controls or within schizophrenia-only cohorts, highlighting major psychiatric confounding.
Cited by
- context Most motorcycle accident victims are infected with Toxoplasma gondii.