Cdc - Dientamoeba Fragilis 225d1x

CDC - Dientamoeba fragilis

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Parasites - Dientamoeba fragilis

Dientamoeba fragilis is a parasite that lives in the large intestine of people. This protozoan parasite produces trophozoites; cysts have not been identified. The intestinal infection may be either asymptomatic or symptomatic. Image: Binucleate (left) and uninucleate (right) trophozoites of D. fragilis, stained with trichrome. (Credit: DPDx (http://dpd.cdc.gov/) ).

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Biology Stages of parasite

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(/parasites/dientamoeba/health_professionals/index.html) Page last reviewed: December 17, 2012 Page last updated: December 17, 2012 Content source: Global Health - Division of Parasitic Diseases and Malaria Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site. http://www.cdc.gov/parasites/dientamoeba/

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CDC - Dientamoeba fragilis - Frequently Asked Questions (FAQs)

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Dientamoeba fragilis FAQs What is Dientamoeba fragilis? Dientamoeba fragilis is a parasite that lives in the large intestine of people. Infection is common worldwide, including in the United States.

What are the symptoms of infection with Dientamoeba fragilis? Many infected people do not have any symptoms. The most common symptoms are diarrhea and abdominal pain. Symptoms also can include loss of appetite, weight loss, nausea, and fatigue. The infection does not spread from the intestine to other parts of the body.

What should I do if I think I might be infected? See your health care provider.

How is infection with Dientamoeba fragilis diagnosed? Your health care provider will ask you to provide stool specimens for testing. Because the parasite is not always found in every specimen, you might be asked to submit stool from more than one day. You might also be tested for pinworm (/parasites/pinworm/index.html) eggs, which sometimes are found in people who are infected with D. fragilis.

Is medication available to treat infection with Dientamoeba fragilis? Yes. Safe and effective medications are available to treat D. fragilis infection.

How do people get infected with Dientamoeba fragilis? This question is difficult to answer because we aren't sure how D. fragilis is spread. Most likely, people get infected by accidentally swallowing the parasite; this is called fecal-oral transmission. The parasite is fragile; it probably cannot live very long in the environment (after it is ed in feces) or in stomach acid (after it is swallowed). An unproven possibility is that pinworm eggs (or the eggs of another parasite) help protect and spread D. fragilis.

Who is at greatest risk for infection? Anyone can become infected with this parasite. However, the risk for infection might be higher for people who live in or travel to settings with poor sanitary conditions.

How can I prevent Dientamoeba fragilis infection? Wash your hands with soap and warm water after using the toilet, after changing diapers, and before preparing or eating food. Teach children the importance of washing hands to prevent infection. More on: Handwashing (/handwashing)

http://www.cdc.gov/parasites/dientamoeba/faqs.html

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CDC - Dientamoeba fragilis - Biology

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Biology Causal Agent: Despite its name, Dientamoeba fragilis is not an ameba but a flagellate. This protozoan parasite produces trophozoites; cysts have not been identified. Infection may be either symptomatic or asymptomatic.

Life Cycle:

The complete life cycle of this parasite has not yet been determined, but assumptions were made based on clinical data. To date, the cyst stage has not been identified in D. fragilis life cycle, and the trophozoite is the only stage found in stools of infected individuals . D. fragilis is probably transmitted by fecal-oral route and transmission via helminth eggs (e.g., Ascaris, Enterobius spp.) has been postulated . Trophozoites of D. fragilis have characteristically one or two nuclei ( , ), and it is found in children complaining of intestinal (e.g., intermittent diarrhea, abdominal pain) and other symptoms (e.g., nausea, anorexia, fatigue, malaise, poor weight gain). Life cycle image and information courtesy of DPDx (http://dpd.cdc.gov/) .

http://www.cdc.gov/parasites/dientamoeba/biology.html

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CDC - Dientamoeba fragilis - Resources for Health Professionals

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Resources for Health Professionals Treatment Examples of several of the most commonly used treatments are provided in the table below. As always, treatment decisions should be individualized. Drug*

Dosage regimen for adults

Iodoquinol 650 mg orally three times daily for 20 days OR Paromomycin 25–35 mg per kg per day orally, in three divided doses, for 7 days OR Metronidazole** 500–750 mg orally three times daily for 10 days *Not FDA-approved for this indication. ** Metronidazole is a nitroimidazole drug. The nitroimidazole drugs secnidazole and ornidazole have been used to treat D. fragilis infection but are unavailable in the United States.

Iodoquinol Iodoquinol is available for human use in the United States.

Note on Treatment in Pregnancy Oral iodoquinol has not been assigned a pregnancy category by the Food and Drug istration. Data on the use of iodoquinol in pregnant women are limited, and risk to the embryo-fetus is unknown. Iodoquinol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Note on Treatment During Lactation It is not known whether iodoquinol is excreted in breast milk. Iodoquinol should be used with caution in breastfeeding women.

Note on Treatment in Pediatric Patients The safety of iodoquinol in children has not been established.

Paromomycin (Oral) Oral paromomycin is available for human use in the United States.

Note on Treatment in Pregnancy Oral paromomycin has not been assigned to a pregnancy category by the Food and Drug istration. Data on the use of oral paromomycin in pregnant women are limited, and the risk to the embryo-fetus probably is low. Oral paromomycin generally is poorly absorbed from the gastrointestinal tract, with minimal, if any, systemic availability.

Note on Treatment During Lactation http://www.cdc.gov/parasites/dientamoeba/health_professionals/index.html

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CDC - Dientamoeba fragilis - Resources for Health Professionals

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Oral paromomycin is unlikely to be excreted in breast milk, and the drug generally is poorly absorbed from the gastrointestinal tract.

Note on Treatment in Pediatric Patients The safety of oral paromomycin in children has not been formally evaluated. However, the safety profiles likely are comparable in children and adults.

Metronidazole Metronidazole is available for human use in the United States.

Note on Treatment in Pregnancy Metronidazole is in pregnancy category B. Data on the use of metronidazole in pregnant women are conflicting. The available evidence suggests use during pregnancy has a low risk of congenital anomalies. Metronidazole may be used during pregnancy in those patients who will clearly benefit from the drug, although its use in the first trimester is generally not advised. Pregnancy Category B: Either animal-reproduction studies have not demonstrated a fetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters).

Note on Treatment During Lactation Metronidazole is excreted in breast milk. The American Academy of Pediatrics classifies metronidazole as a drug for which the effect on nursing infants is unknown but may be of concern. The World Health Organization (WHO) advises to avoid metronidazole treatment in lactating women. Metronidazole should be used during lactation only if the potential benefit of therapy to the mother justifies the potential risk to the infant.

Note on Treatment in Pediatric Patients The safety of metronidazole in children has not been established. Metronidazole is listed as an antiamebic and antigiardiasis medicine on the WHO Model List of Essential Medicines for Children, intended for the use of children up to 12 years of age.

References Stark D, Barratt J, Roberts T, et al. A review of the clinical presentation of dientamoebiasis. Am J Trop Med Hyg 2010;82:614–9. Kurt O, Girginkardesler N, Balcioglu IC, et al. A comparison of metronidazole and single-dose ornidazole for the treatment of dientamoebiasis. Clin Microbiol Infect 2008;14:601–4. Vandenberg O, Souayah H, Mouchet F, et al. Treatment of Dientamoeba fragilis infection with paromomycin. Pediatr Infect Dis J 2007;26:88–90. Vandenberg O, Peek R, Souayah H, et al. Clinical and microbiological features of dientamoebiasis in patients suspected of suffering from a parasitic gastrointestinal illness: a comparison of Dientamoeba fragilis and Giardia lamblia infections. Int J Infect Dis 2006;10:255–61. Girginkardesler N, Coskun S, Balcioglu IC, et al. Dientamoeba fragilis, a neglected cause of diarrhea, successfully treated with secnidazole. Clin Microbiol Infect 2003;9:110–3. Norberg A, Nord CE, Evengard B. Dientamoeba fragilis—a protozoal infection which may cause severe bowel distress. Clin Microbiol Infect 2003;9:65–8. Preiss U, Ockert G, Broemme S, et al. On the clinical importance of Dientamoeba fragilis infections in childhood. J Hyg Epidemiol Microbiol Immunol 1991;35:27-34.

This information is provided as an informational resource for licensed health care providers as guidance only. It is not intended as a substitute for professional judgment. http://www.cdc.gov/parasites/dientamoeba/health_professionals/index.html

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CDC - DPDx - Dientamoeba

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DPDx - Laboratory Identification of Parasitic Diseases of Public Health Concern

Parasites A-Z Diagnostic Procedures Diagnostic Assistance Training About DPDx DPDx is an education resource designed for health professionals and laboratory scientists. For an overview including prevention and control visit www.cdc.gov/parasites/dientamoeba.

Dientamoeba fragilis Infection [Dientamoeba fragilis] Parasite Biology Image Gallery Laboratory Diagnosis Treatment Information

http://www.cdc.gov/dpdx/dientamoeba/index.html

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CDC - DPDx - Dientamoeba

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Binucleate form of a trophozoite of Dientamoeba fragilis, stained with trichrome.

Uninucleate form of a trophozoite of D. fragilis, stained with trichrome.

Causal Agents Despite its name, Dientamoeba fragilis is not an ameba but a flagellate. This protozoan parasite produces trophozoites; cysts have not been identified. Infection may be either symptomatic or asymptomatic.

Life Cycle

http://www.cdc.gov/dpdx/dientamoeba/index.html

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CDC - DPDx - Dientamoeba

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The complete life cycle of this parasite has not yet been determined, but assumptions were made based on clinical data. To date, the cyst stage has not been identified in D. fragilis life cycle, and the trophozoite is the only stage found in stools of infected individuals . D. fragilis is probably transmitted by fecal-oral route and transmission via helminth eggs (e.g., Ascaris, Enterobius spp.) has been postulated . Trophozoites of D. fragilis have characteristically one or two nuclei ( , ), and it is found in children complaining of intestinal (e.g., intermittent diarrhea, abdominal pain) and other symptoms (e.g., nausea, anorexia, fatigue, malaise, poor weight gain).

Geographic Distribution Worldwide.

Clinical Presentation Symptoms that have been associated with infection include diarrhea, abdominal pain, anorexia, nausea, vomiting, fatigue, and weight loss. For Questions About DPDx Us Page last reviewed: (@update) Page last updated: (@update) Content source: Global Health - Division of Parasitic Diseases and Malaria Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site.

Centers for Disease Control and Prevention 1600 Clifton Rd. Atlanta, GA 30333, USA 800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - CDC–INFO http://www.cdc.gov/dpdx/dientamoeba/index.html

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CDC - DPDx - Dientamoeba - Laboratory Diagnosis

1/16/14, 5:29 PM

DPDx - Laboratory Identification of Parasitic Diseases of Public Health Concern

Parasites A-Z Diagnostic Procedures Diagnostic Assistance Training About DPDx DPDx is an education resource designed for health professionals and laboratory scientists. For an overview including prevention and control visit www.cdc.gov/parasites/dientamoeba.

Dientamoeba fragilis Infection [Dientamoeba fragilis] Parasite Biology Image Gallery Laboratory Diagnosis Treatment Information

Laboratory Diagnosis Infection is diagnosed through detection of trophozoites in permanently stained fecal smears (e.g., trichrome). This parasite is not detectable by stool concentration methods. Dientamoeba fragilis trophozoites can be easily overlooked because they are pale-staining and their nuclei may resemble those of Endolimax nana or Entamoeba hartmanni.

Morphology More on: Morphologic comparison with other intestinal parasites. For Questions About DPDx Us Page last reviewed: (@update) Page last updated: (@update) Content source: Global Health - Division of Parasitic Diseases and Malaria Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site.

http://www.cdc.gov/dpdx/dientamoeba/dx.html

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CDC - DPDx - Dientamoeba - Treatment Information

1/16/14, 5:30 PM

DPDx - Laboratory Identification of Parasitic Diseases of Public Health Concern

Parasites A-Z Diagnostic Procedures Diagnostic Assistance Training About DPDx DPDx is an education resource designed for health professionals and laboratory scientists. For an overview including prevention and control visit www.cdc.gov/parasites/dientamoeba.

Dientamoeba fragilis Infection [Dientamoeba fragilis] Parasite Biology Image Gallery Laboratory Diagnosis Treatment Information

Treatment Information Safe and effective drugs are available. The drug of choice is iodoquinol. Paromomycin*, tetracycline*, (contraindicated in children under age 8, pregnant and lactating women) or metronidazole can also be used. * This drug is approved by the FDA, but considered investigational for this purpose. This information is provided as an informational resource for licensed health care providers as guidance only. It is not intended as a substitute for professional judgment. For Questions About DPDx Us Page last reviewed: (@update) Page last updated: (@update) Content source: Global Health - Division of Parasitic Diseases and Malaria Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site.

http://www.cdc.gov/dpdx/dientamoeba/tx.html

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