SUMMARYWe sought to determine the frequency of serological markers of selected infections in a population of psychiatric patients in Durango City, Mexico, and to determine whether there are any epidemiological characteristics of the subjects associated with the infections. One hundred and five inpatients of a public psychiatric hospital of Durango were examined for HBsAg, anti-HCV antibodies, anti-HIV antibodies, anti-Brucella antibodies, rapid plasma reagin and anti-Cysticercus antibodies by commercially available assays. Anti-Cysticercus antibodies were confirmed by Western blot and HBsAg by neutralization assay. Epidemiological data from each participant were also obtained. Seroprevalences of HBsAg, anti-HCV, anti-HIV, anti-Brucella, rapid plasma reagin and anti-Cysticercus antibodies found were 0.0%, 4.8%, 0.9%, 0.0%, 1.9%, and 0.9%, respectively. Overall, 9 (8.6%) inpatients showed seropositivity to any infection marker. We concluded that our psychiatric inpatients have serological evidence of a number of infections. HCV is an important pathogen among our psychiatric inpatients. Health care strategies for prevention and control of infections in Mexican psychiatric patients should be considered.KEYWORDS: Psychiatric patients; Infections; Prevalence; Virus; Parasite; Bacteria. INTRODUCTIONPsychiatric patients have been found to suffer from a number of infections in a higher frequency than other populations, and the prevalence of infections in psychiatric patients may vary substantially among countries. Prevalence studies indicate that psychiatric patients have a significantly higher frequency of anti-Cysticercus antibodies than those observed in the general population or healthy control subjects. In a Venezuelan study, 18.4% of the psychiatric inpatients studied were positive in the blood test for cysticercosis as compared to only 1.6% prevalence in the control group 7 . Similarly, a study carried out in Brazil showed that 5% of the patients admitted to a psychiatric hospital were positive for anti-Cysticercus antibodies while only 2.3% prevalence was found in adults of the general population group 12 . Reports also indicate that patients with mental illnesses have a high prevalence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infections. In an American study, researchers found that the prevalence of HIV in individuals with severe mental illness was approximately eight times the estimated US population rate, and prevalence rates of HBV and HCV were approximately five and 11 times the overall estimated population rates for these infections, respectively 10 . In an Indian study, newly registered adult psychiatric outpatients at a general hospital showed significantly higher seroprevalence of HIV infection than healthy blood donors (1.03% versus 0.5%, respectively) 11 . For its part, patients with Brucella infection may manifest central nervous system involvement, and neurobrucellosis should be considered in patients with unexplained psychiatric and neurological sym...