Prevalence and subtype diversity of Blastocystis hominis among gastroenteritis patients in northern and central Jordan.

BACKGROUND

Blastocystis hominis is a common intestinal eukaryotic organism that infects both humans and animals. Although its pathogenicity remains debated, it has been associated with diarrhoea and gastroenteritis. This study aimed to determine its prevalence and characterize its genetic subtypes (STs) in symptomatic patients presenting with gastrointestinal complaints.

METHODS

DNA was extracted from 279 stool samples collected from patients in northern and central regions of Jordan. Nested polymerase chain reaction targeting the 18S rRNA gene locus and Sanger sequencing of positive samples were used for B. hominis detection and subtype identification. Phylogenetic relationships were analysed using Unipro UGENE and MEGA software. Statistical analyses, prevalence, Pearson's χ2 test (p<0.05) were conducted using SPSS.

RESULTS

The present study found a B. hominis prevalence of 7.2% (20/279). Three subtypes were identified: ST1 35% (7/20), ST2 10% (2/20) and ST3 55% (11/20). No mixed-subtype infections were detected. A statistically significant association was observed between B. hominis infection and patient age (p<0.05), with infection rates influenced by age and not by gender. The highest prevalence, based on sequencing, was observed in the 6- to <12-y age group. The association between B. hominis infection and gender was not statistically significant.

CONCLUSIONS

The relatively low prevalence of B. hominis among patients suggests it may function more as an indicator of gut health rather than as a primary pathogen. However, confirmation of this hypothesis requires additional microbiome and longitudinal studies. The frequent detection of ST1 and ST3 aligns with previous findings that link these subtypes to clinical symptoms. Broader epidemiological studies are needed to clarify the distribution patterns and clinical significance of B. hominis in human populations.