Dientamoeba fragilis, a Commensal in Children in Danish Day Care Centers

Abstract

Dientamoeba fragilis is an intestinal protozoan of debated clinical significance. Here, we present cross-sectional and longitudinal observations on D. fragilis in children aged 0 to 6 years from a 1-year multi-day-care-center cohort study set in Copenhagen, Denmark. The inclusion period for the cohort was 2009 through 2012. Stool samples collected from the children were accompanied by questionnaires completed by the parents or guardians of the children. Using real-time PCR, D. fragilis was detected in the first stool sample from 97 of 142 (68.3%) children. We evaluated the associations between seven plausible risk factors (age, sex, having siblings, having domestic animals at home, having had infant colic, recent history of intake of antibiotics, and recent history of travel abroad) as well as six reported symptoms (lack of appetite, nausea, vomiting, abdominal pain, weight loss, and diarrhea) and testing positive for D. fragilis. The final multivariable model identified being Ͼ3 years old and having a history of recent travel abroad as risk factors for testing positive for D. fragilis. Moreover, univariable analyses indicated that having siblings was a risk factor. There was no statistical association between a recent history of gastrointestinal symptoms and testing positive for D. fragilis. Among the 108 children who were represented by Ն2 samples and thus included in the longitudinal analysis, 32 tested negative on the first sample and positive later, and the last sample from each of the 108 children was positive. The results are in support of D. fragilis being a common enteric commensal in this population.KEYWORDS Denmark, dientamoebiasis, infants, preschoolers, risk factors, symptoms, toddlers D ientamoeba fragilis is an intestinal protozoan of debated clinical significance (1-7). In Denmark, D. fragilis appears to be common in the apparently healthy adult population (8); meanwhile, baseline data on the prevalence in apparently healthy children are lacking. Dientamoeba fragilis is commonly detected in stools from children tested for gastrointestinal pathogens, with a peak (ca. 70% of samples positive) in 7-year-olds (9). A randomized placebo-controlled clinical trial failed to show improved clinical outcome in D. fragilis-positive children treated with metronidazole compared with those treated with a placebo, and the observed eradicative effect of metronidazole was moderate and transient, and a spontaneous decrease in the proportion of children testing positive was observed in the placebo group (10).We recently established an open cohort of children aged 0 to 6 years attending municipal day care centers in Copenhagen, Denmark, with a primary research focus on investigating enteroaggregative Escherichia coli over time (11-13). Using real-time PCR (14), DNA of D. fragilis was detected in the majority (516/688 [75.0%]) of the stool

Dientamoeba fragilis diagnosis by fecal screening: relative effectiveness of traditional techniques and molecular methods

“…Many studies have shown correlation of infection with D. fragilis and clinical symptoms [3,8,9,13,39], while others report no relationship between symptomatic infection and this parasite [44][45][46]. This disparity is not surprising, as manifestations ranging from subclinical to severe gastrointestinal symptoms is typically observed in parasitic enteropathogen infections.…”

Optimization of routine microscopic and molecular detection of parasitic protozoa in SAF-fixed faecal samples in Sweden

“…dispar cysts was positive for E. histolytica with real-time PCR, which underlines the need for typing of these species [14,49,50]. The pathogenic role of D. fragilis has been debated [16][17][18]21,51,52] and the need for screening is questioned. A recent study from Finland also shows that wet mount screening was useful for D. fragilis detection [20].…”

“…Dientamoeba fragilis is common, but confirmation of virulence and the potential mechanisms of pathogenicity are yet to be determined [16][17][18][19][20]. Reported prevalence figures vary depending on methods used, patient population and location [20][21][22][23]. Trophozoites of G. intestinalis and E. histolytica are analysed either as motile in fresh samples or by staining of SAF-fixed samples, mainly only on request.…”

Natural infection withGiardiais associated with altered community structure of the human and canine gut microbiome

“…Infection with eukaryotic pathogens often results in acute, moderate-to-severe diarrheal disease and/or chronic malnutrition and stunting, which has 48 significant consequences for morbidity and mortality (3)(4)(5). Conversely, some intestinal 49 parasites are frequently associated with asymptomatic infections, or are even considered 50 commensal (6,7). Giardia, for example, was found in 18 of 1093 (1.6%) of healthy volunteers in 51…”