Distribution and relevance of Dientamoeba fragilis and Blastocystis species in gastroenteritis: results from a case-control study

• Published in: European journal of clinical microbiology & infectious diseases Vol. 39; no. 1; pp. 197 - 203
• Main Authors: de Boer, Maria Dullaert, Schuurs, Theo A., Vermeer, Marloes, Ruijs, Gijs J.H.M., van der Zanden, Adri G. M., Weel, Jan F., Bruijnesteijn van Coppenraet, Lesla E.S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2020; Springer Nature B.V
• Subjects: Age; Biomedical and Life Sciences; Biomedicine; Blastocystis; Case studies; Children; Diarrhea; Dientamoeba fragilis; Gastroenteritis; Gastrointestinal symptoms; Internal Medicine; Intestine; Medical Microbiology; Microbiomes; Original Article; Population studies; Samples; Statistical analysis; Statistical methods; Statistical significance; Diarrhea; Multiplexed real-time PCR; Gastroenteritis; Case-control; Dientamoeba fragilis; Blastocystis
• ISSN: 0934-9723; 1435-4373; 1435-4373
• DOI: 10.1007/s10096-019-03710-z

The actual role of Dientamoeba fragilis and Blastocystis in patients with gastrointestinal symptoms is still under debate. A multicenter case-control study was performed in The Netherlands to elucidate the clinical relevance of molecular diagnostics results in gastroenteritis (GE). Samples from this case-control study were used to perform a detailed analysis on the presence of D. fragilis and Blastocystis in relation to gastrointestinal symptoms. In the present study, a real-time PCR for Blastocystis was performed on 1374 case samples and 1026 control samples from the multicenter gastroenteritis case-control study previously tested for D. fragilis . Prevalence of both micro-organisms was highest in children under 20 years of age and lowest in the oldest age group. A significantly lower overall detection of D. fragilis and Blastocystis was found in cases (both 25.8%) as compared to controls (37.6% and 40.0%, respectively). The difference for D. fragilis was statistically significant for subjects above 20 years of age. For Blastocystis , the difference was statistically significant in all age groups, except in children less than 5 years of age. A negative relation between D. fragilis -positive cases and diarrhea was found in this study population. More GE symptoms were reported in cases without D. fragilis or Blastocystis . In the present study, prevalence of both D. fragilis and Blastocystis is lower in cases with gastroenteritic symptoms than in controls. Besides, in cases with D. fragilis or Blastocystis , no association is shown between any of the GE symptoms. Interestingly, this suggests that the presence of these protozoans may be considered characteristic of a healthy intestinal microbiome.