Association of Blastocystis subtypes with diarrhea in children

Blastocystis hominis is an intestinal zoonotic protozoa that epidemiological surveys have shown, is highly prevalent among children and may cause chronic diarrhea. This study aimed to identify Blastocystis subtypes among children and associate those subtypes to pathology. The study's population was children aged 6–12 years old divided into asymptomatic and symptomatic (diarrhea) groups. The asymptomatic samples were obtained from primary school students in the Bukit Duri area of South Jakarta, while the symptomatic samples were obtained from patients who visited nearby primary health centers (Puskesmas). Symptomatic stool samples were examined inParasitology Laboratory FKUI. Microscopic examination of the stool samples was performed to screen for single Blastocystic infection, followed by culture, PCR of 18S rRNA, and sequencing. In the study, 53.2% of children (n = 156) harbored intestinal parasites, Blastocysts sp. A single infection of Blastocystis sp. was present in 69 (44.23%) samples, comprised of 36 symptomatic and 33 asymptomatic participants. The Blastocystis subtypes (STs) identified in this study were STs 1–4; ST3 was the most dominant and was observed with statistically significant higher frequency in the symptomatic group. ST4 was only found in one sample in the symptomatic group. While ST1 and ST2 were found more frequently in the asymptomatic group, no statistical association was observed. ST3 is more likely to be associated with clinical symptoms than ST1 and ST2.