Blastocystis and Giardia duodenalis infection in a male prison in Spain.

Abstract

Background: General conditions in a prison may facilitate water- or food-borne infections. Methods: Detection of intestinal parasites was achieved in 471 male prison inmates by standard microscopic procedures on their stool samples. Positive samples were processed by PCR amplification of a 600-bp fragment of the Blastocystis SSU rRNA gene and partial sequences of the Giardia duodenalis bg genes. Identification of subtypes/genotypes was based on Sanger sequencing methods. Results: Blastocystis was found in 7.9 % (37/471) and G. duodenalis was found in 2.1 % (10/471). Out of the 37 Blastocystis positive samples, 54 % (20/37) were successfully subtyped, allowing the identification of the subtypes ST3 (50 %), ST1 (25 %), ST2 (15 %), ST4 (5 %) and ST6 (5 %). Out of 10 G. duodenalis positive samples, 50 % (5/10) were successfully genotyped, allowing the identification of genotypes A (80 %) and B (20 %). Conclusions: The predominance of ST3 within the prison inmates, together with its low intra-ST genetic variability, reflected inter-human transmission with spatial stability. The G. duodenalis distribution is not wide enough to consider the possibility of a generalized transmission via contaminated water or food. Personal hygiene practices among male prison inmates may be an important measure to prevent the transmission.