No correlation between clinical symptoms and Blastocystis hominis in immunocompetent individuals.
Abstract Background and Aim: Previous reports regarding the clinical significance and pathogenicity of Blastocystis hominis have been contradictory. The aim of this study was to examine the association between Blastocystis and gastrointestinal symptoms in immunocompetent individuals.


METHODS
We monitored over 2800 healthy people for a period of 15 months, and took stool specimens during both asymptomatic periods and during periods of gastrointestinal symptoms.


RESULTS
After exclusion of individuals who had simultaneous identification of other fecal pathogens, we compared the proportions of asymptomatic versus symptomatic individuals positive for Blastocystis and found no significant difference (P = 0.5). Symptom status did not correlate with parasite abundance. We found that some individuals were likely to have Blastocystis detected during both asymptomatic and symptomatic periods, possibly suggesting carriage of the organism.


CONCLUSIONS
In conclusion, we found no correlation between clinical symptoms and the presence or absence of Blastocystis among this healthy cohort.
Leder
Karin
K
Department of Epidemiology and Preventive Medicine, Monash University, The Alfred Hospital, Melbourne, Victoria, Australia. karin.leder@med.monash.edu.au
Hellard
Margaret E
ME
Sinclair
Martha I
MI
Fairley
Christopher K
CK
Wolfe
Rory
R
D000293:Adolescent; D000328:Adult; D000818:Animals; D016776:Blastocystis Infections / Q000150:complications* / Q000276:immunology / Q000469:parasitology; D016845:Blastocystis hominis; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005243:Feces / Q000469:parasitology; D005260:Female; D005767:Gastrointestinal Diseases / Q000276:immunology / Q000469:parasitology*; D006801:Humans; D007121:Immunocompetence; D008297:Male