Dientamoebiasis in Children
See also Dientamoebiasis in adults Dientamoebiasis in Adults
Essentials
- The significance of the protozoan parasite Dientamoeba fragilis (DF) as a pathogen in children is highly disputable.
- With new methods, DF can often be found in children (in as many as 50-70%) regardless of whether they have abdominal complaints.
- In a basically healthy child below 16 years with unspecific intestinal symptoms, DF infection should not be sought.
- As there is no evidence of its efficacy, antimicrobial treatment is not recommended for children.
Infection and epidemiology
- DF is an intestinal parasite of the Trichomonadea genus. As the name suggests, it is fragile and capable of living outside the body for 6-48 hours, only.
- The mode of transmission is still unclear and the cystic form transmitting the infection has not been indisputably shown.
- The prevalence of the infection varies greatly in different populations and depending on the research method. DF has been found in as many as 50-70% of asymptomatic children in various studies.
Symptoms
- As DF is found equally often in asymptomatic controls as in children with symptoms, it is not clear if there is a connection between the DF finding and the symptoms.
- Abdominal complaints linked to DF infection, such as unspecific, chronically recurrent abdominal pain and diarrhoea, typically occur in association with functional abdominal complaints. Functional abdominal complaints are common in children, and testing for DF is not needed for differential diagnosis.
Diagnosis
- In a basically healthy child below 16 years with unspecific intestinal symptoms, DF infection should not be sought.
- DF can be detected by microscopic examination of a faecal sample.
- The finding can be confirmed by faecal nucleic acid detection test.
- In addition to DF, most tests detect several other protozoa, such as Giardia lamblia, Cryptosporidium spp and Entamoeba histolytica.
- In some laboratories, testing for DF needs to be specifically requested.
Treatment
- As there is no evidence of its efficacy, antimicrobial treatment is not recommended for children.
- One placebo-controlled double-blind trial has been conducted in children, where symptomatic child patients were treated with metronidazole or placebo.
- DF was more often eradicated in the active treatment group but the difference in carriership between the groups evened out in as soon as 2 months. However, as symptoms were eliminated equally effectively in both groups, it is unjustified to use metronidazole in outpatient care if DF is found in a child.
Prognosis
- In studies done in children, even successful eradication therapy has not correlated with clinical recovery.
- A recent Finnish retrospective study based on patient records found that 10/26 (38%) of treated children no longer had DF in their faeces. Clinical recovery did not correlate with whether the parasite was eradicated.
References
- Johnson EH, Windsor JJ, Clark CG. Emerging from obscurity: biological, clinical, and diagnostic aspects of Dientamoeba fragilis. Clin Microbiol Rev 2004;17(3):553-70, table of contents. [PubMed]
- Stark D, Roberts T, Marriott D et al. Detection and transmission of Dientamoeba fragilis from environmental and household samples. Am J Trop Med Hyg 2012;86(2):233-6. [PubMed]
- Clark CG, Röser D, Stensvold CR. Transmission of Dientamoeba fragilis: pinworm or cysts? Trends Parasitol 2014;30(3):136-40. [PubMed]
- Ögren J, Van Nguyen S, Nguyen MK et al. Prevalence of Dientamoeba fragilis, Giardia duodenalis, Entamoeba histolytica/dispar, and Cryptosporidium spp in Da Nang, Vietnam, detected by a multiplex real-time PCR. APMIS 2016;124(6):529-33. [PubMed]
- Brands MR, Van de Vijver E, Haisma SM et al. No association between abdominal pain and Dientamoeba in Dutch and Belgian children. Arch Dis Child 2019;104(7):686-689. [PubMed]
- Pietilä JP, Meri T, Siikamäki H et al. Dientamoeba fragilis - the most common intestinal protozoan in the Helsinki Metropolitan Area, Finland, 2007 to 2017. Euro Surveill 2019;24(29):. [PubMed]
- Robin SG, Keller C, Zwiener R et al. Prevalence of Pediatric Functional Gastrointestinal Disorders Utilizing the Rome IV Criteria. J Pediatr 2018;195():134-139. [PubMed]
- de Jong MJ, Korterink JJ, Benninga MA et al. Dientamoeba fragilis and chronic abdominal pain in children: a case-control study. Arch Dis Child 2014;99(12):1109-13. [PubMed]
- Röser D, Simonsen J, Stensvold CR et al. Metronidazole therapy for treating dientamoebiasis in children is not associated with better clinical outcomes: a randomized, double-blinded and placebo-controlled clinical trial. Clin Infect Dis 2014;58(12):1692-9. [PubMed]
- Bruijnesteijn van Coppenraet LE, Dullaert-de Boer M, Ruijs GJ et al. Case-control comparison of bacterial and protozoan microorganisms associated with gastroenteritis: application of molecular detection. Clin Microbiol Infect 2015;21(6):592.e9-19. [PubMed]