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Description:Magnified 128X, this photomicrograph revealed the presence of a cestode, Diphyllobothrium latum, or “fish” or “broad” tapeworm, egg, which is described as oval or ellipsoidal, and ranges in size from 55µm to 75µm X 40µm to 50µm. There is an operculum at one end that can be inconspicuous, and at the opposite (abopercular) end is a small knob that can be barely discernible. The eggs are passed in the stool unembryonated.
Clinical Features:

Diphyllobothriasis can be a long-lasting infection (decades). Most infections are asymptomatic. Manifestations may include abdominal discomfort, diarrhea, vomiting, and weight loss. Vitamin B12 deficiency with pernicious anemia may occur. Massive infections may result in intestinal obstruction. Migration of proglottids can cause cholecystitis or cholangitis.

Laboratory Diagnosis:

Microscopic identification of eggs in the stool is the basis of specific diagnosis. Eggs are usually numerous and can be demonstrated without concentration techniques. Examination of proglottids passed in the stool is also of diagnostic value.

High Resolution: Click here for hi-resolution image (6.53 MB)
Content Providers(s):CDC/ Dr. Mae Melvin
Creation Date:1979
Photo Credit:
Links:CDC – Div. of Parasitic Diseases: Diphyllobothriasis
CDC Organization
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Copyright Restrictions:None - This image is in the public domain and thus free of any copyright restrictions. As a matter of courtesy we request that the content provider be credited and notified in any public or private usage of this image.