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Graham Clark graham.clark at LSHTM.AC.UK
Mon Aug 10 09:06:14 EST 1998

Dear 2819932370 (if that is your real name!),

Dientamoeba fragilis is a parasite related to Trichomonas. As far =

as treatment of  D. fragilis is concerned, physicians are divided =

over whether to treat carriers of the parasite or not. In general, =

most will not unless there are symptoms associated with the infection =

(usually diarrhea). There ARE treatments to eradicate the parasite, =

however. =

I am not a physician so I cannot give you specific recommendations.
However, from my knowledge of the organism I can tell you that the =

following drugs have been reported as being used successfully in the =


Metronidazole (also known as Flagyl), iodoqinol or diiodohydroxyquin,
and, (less frequently) oxytetracycline, doxycycline and erythromycin.
The last three probably do not affect the parasite directly but rather
affect the bacteria in the gut that are eaten by Dientamoeba.

Dientamoeba fragilis infection has been associated with diarrhea and =

other gastrointestinal complaints, but not with any life-threatening =

disease. Not many people actually work on the organism so surprisingly =

little is known about its basic biology other than through microscopy.

Its transmission remains a mystery as the organism does not appear to =

have a resistant stage. Direct transmission via ingestion of faecally =

contaminated food or on contaminated fingers is the most likely route, =

but others ways have been suggested. As William Reeder says, one of the
suggested methods is in pinworm eggs, but this is far from being proved
as far as I know. Many people infected with Dientamoeba are NOT infected
with pinworms so the link is not clear.

Surveys that have specifically looked for the parasite have =

often shown 5% or so of people in western countries to be infected. =

Its only known hosts are humans and other primates so it is unlikely
to be acquired from, for example, pets or domestic livestock. Most =

infected people do NOT, as far as is known, develop symptoms. It is
also not easy to diagnose and so it may be more common than we think.

As I said there is a lot we don't know about this organism but I hope
this information is helpful.


Graham Clark
-- =

C. Graham Clark, Ph.D.
Department of Infectious and Tropical Diseases,
London School of Hygiene and Tropical Medicine,
Keppel Street, London WC1E 7HT, England, G.B.

Tel: ++44-171-927-2351
FAX: ++44-171-636-8739
e-mail: g.clark at lshtm.ac.uk
Homepage: http://www.lshtm.ac.uk/mp/bcu/enta/mpvbgcla.htm

Please visit the Entamoeba Homepage -

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