Risk of Dementia in Patients with Toxoplasmosis- A Nationwide, Population-based Based Cohort Study in Taiwan

Background Toxoplasma gondii (T. gondii) has infected about 25–30% of individuals worldwide, and it was difficult to detect its latent status. We aimed to evaluate the association between toxoplasmosis, the risk of dementia, and the effects of antibiotics in Taiwan. Material and methods This nationwide, population-based, retrospective cohort study was conducted by using the two million Longitudinal Health Insurance Database retrieved from Taiwan’s National Health Insurance Research Database. The Fine and Gray’s competing risk analysis was used for the development of dementia in the toxoplasmosis cohort relative to the non-toxoplasmosis cohort. A sensitivity analysis was also conducted. The effects of the antibiotics (sulfadiazine or clindamycin) on the risk of dementia were also analyzed. Results We enrolled a total of 800 subjects, and identified 200 patients with toxoplasmosis and 600 sex- and age-matched controls without toxoplasmosis infections in a ratio of 1:3, selected between 2000 and 2015. The crude hazard ratio (HR) of the risk in the development of dementia was 2.570 (95% confidence interval [CI] = 1.511-4.347, p p