Parasitic invasion caused by blastocystis spp. in the practice of the gastroenterologist: modern diagnostics and treatment


I.G. Bakulin, L.P. Zueva, M.S. Zhuravleva, D.V. Azarov, A.E. Goncharov, L.N. Belousova, Т.Е. Skvortsova, S.G. Belov

North-Western State Medical University n.a. I.I. Mechnikov, St. Petersburg, Russia
Background. Infectious and parasitic diseases are one of the leading factors in the development of the pathology of the gastrointestinal tract; currently, blastocystis invasion deserves special attention. Objective: to determine the prevalence of blastocystis invasion in patients with gastroenterological pathology. Methods. Using the continuous sampling method, study included 130 patients with diseases of the digestive system who received outpatient and inpatient care between March and June 2018, with mean age 46.9±15.9 years (19 to 80 years), with prevalence of female persons (68.5%). The detection of blastocystis invasion was performed by the method of microscopy of direct fecal extract with 2% Lugol’s solution and by polymerase chain reaction (PCR) with the genus-specific primers to SSU rDNA Blastocystis spp. Results. With microscopic examination of the direct fecal extraction, Blastocystis spp. were detected in 10.0% (n=13) of the total number of examined patients; with the use of PCR method – in 11.54% (n=15). The clinical symptoms of blastocyst invasion were non-specific: most patients (n=14; 86.7%) had symptoms of intestinal dyspepsia. Conclusion. The prevalence of blastocyst invasion in gastroenterological patients was 11.54%. The absence of specific clinical symptoms makes it difficult to diagnose the invasion caused by Blastocystis spp. and indicates the need for a screening examination of all patients of the gastroenterological profile, especially in the presence of symptoms of intestinal dyspepsia.
Keywords: parasitic invasions, blastocysts, irritable bowel syndrome, abdominal pain syndrome, diarrhea, constipation

About the Autors

Corresponding author: Maria S. Zhuravleva, PhD, Teaching Assistant at the Department of Propaedeutics of Internal Diseases, Gastroenterology and Dietology, NWSMU n.a. I.I. Mechnikov, St. Petersburg, Russia; e-mail:
Address: 41, Kirochnaya Street, St. Petersburg, 191015 Russian Federation

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