Relationship between Toxoplasma Gondii Infection and Neurological Disorders: A Systematic Review

Abstract

Toxoplasma gondii infection has traditionally been considered a zoonosis with an asymptomatic course; however, recent research has suggested its involvement in various neurological and neuropsychiatric disorders. The aim of this study was to analyze the relationship between toxoplasmosis and alterations of the human nervous system through a systematic review of the scientific literature. A structured search was conducted in biomedical databases (PubMed, Scopus, SciELO, RedALyC, Google Scholar) using key descriptors combined with Boolean operators. Studies published between 2013 and 2024, conducted in humans, peer-reviewed, and with full-text access were included. From a total of 57 initial studies, 41 articles that met the inclusion criteria were selected. The results were organized into four categories: congenital toxoplasmosis is associated with severe neurological sequelae such as hydrocephalus, intracranial calcifications, and seizures, particularly when infection occurs during the first trimester. Complex neuroimmunological mechanisms were identified, including microglial activation, persistent neuroinflammation, and disruption of neurotransmitters such as dopamine and GABA. An epidemiological association between chronic infection and disorders such as schizophrenia, bipolar disorder, Alzheimer’s disease, and epilepsy was also observed. Despite the existence of clinical guidelines, challenges remain in early diagnosis and timely treatment. It is concluded that toxoplasmosis represents an underestimated neurological risk that requires attention from an interdisciplinary perspective involving public health, clinical diagnosis, and biomedical research.