The global seroprevalence of latent toxoplasmosis is estimated to be higher than 30%. The presence of slowly dividing parasites in tissue cysts located mainly in immunoprivileged organs was long considered asymptomatic. Recently, many studies have shown that latent Toxoplasma infections could have serious impacts on human health. Here we ran a cross-sectional study in a population of 1486 volunteers. The results showed that 333 infected subjects scored worse than 1153 controls in 28 of 29 health-related variables. Similarly, they reported higher rates of 77 of a list of 134 disorders reported by at least 10 participants of the study. Toxoplasmosis was associated most strongly with musculoskeletal (τ = 0·107, P < 0·0005), followed by neurological (τ = 0·088, P < 0·0005), immune (τ = 0·085, p < 0·0005), metabolic (τ = 0·079, P < 0·0005), respiratory (τ = 0·068, P = 0·0001), allergic (τ = 0·053, P = 0·004), digestive system (τ = 0·052, P = 0·004) and mental health disorders (τ = 0·050, P = 0·008). Results of the present cohort study, along with the previous data from many case-control studies or ecological studies suggest that latent toxoplasmosis represents a large and so far underrated public health problem.