First Case-Control Study of Intestinal Parasites in Follow-up Schizophrenia Patients: Are We Overlooking the Role of These Agents?

Abstract

Introduction: Disability and decrease in the quality of life owing to the nature of schizophrenia are considered factors that predispose patients to parasitic infections. This study aimed to investigate intestinal parasites in schizophrenia and healthy volunteers with similar age-gender data and to contribute to the literature and/or clinical practice by determining the underlying cause of gastrointestinal complaints (such as side effects of psychiatric drugs or overlooked parasitic infection) in patients with schizophrenia. Methods: This case-control study included 30 patients with schizophrenia and 30 healthy volunteers. Their stool samples were examined for the presence of intestinal parasites primarily microscopically or serologically in cases requiring differential diagnosis. Results: The overall positivity rate of intestinal parasites was 25% (15/60). The difference between the intestinal parasite detection rates, which was 36.7% (11/30) in the schizophrenia group and 13.3% (4/30) in the healthy control group, was significant (odds ratio: 3.76; 95% confidence interval: 1.04-13.65; p<0.05). The distribution of parasite species varied: 6 (20%) patients had Blastocystis spp., 3 (10%) had Giardia intestinalis (G. intestinalis), and 2 (6.7%) had Entamoeba histolytica in the schizophrenia group, whereas 3 (10%) had Blastocystis spp. and 1 (3.3%) had G. intestinalis in the healthy control group. Conclusion: To increase the quality of life of patients with a chronic psychiatric disease such as schizophrenia and to prevent possible transmission, periodic examination of parasitic agents is necessary in addition to psychiatric treatment and further studies are needed.