Diphyllobothriasis Workup

Updated: Jun 13, 2019
  • Author: David R Haburchak, MD, FACP; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Laboratory Studies

Laboratory studies that may be used in the diagnosis of diphyllobothriasis include the following:

  • Microscopic stool examination for ova and parasites [23]
  • Complete blood count (CBC) - Eosinophilia may be present
  • Hemoglobin level and hematocrit - These may be below or at the lower end of the reference range
  • Mean cell volume - This may be above or at the higher end of the reference range
  • Peripheral smear
  • Vitamin B-12 level
  • Folate level

Diagnosis of D latum infection is based on identification of the operculated eggs in the stool (see the images below). Usually, this is not difficult, because of the large quantity of eggs (≥1 million) produced each day.

Proglottids of Diphyllobothrium latum. Proglottids of Diphyllobothrium latum.
Egg of Diphyllobothrium latum with arrow pointing Egg of Diphyllobothrium latum with arrow pointing to operculum.

The anemia produced by diphyllobothriasis is typically associated with increased free hydrochloric acid in gastric juice, in contrast to the relative achlorhydria invariably observed in true pernicious anemia.

A multiplex polymerase chain reaction (PCR) has been described. [24]


Other Studies

In general, no imaging studies are required to evaluate diphyllobothriasis, unless they are clinically indicated by other aspects of the patient’s presentation. For example, patients who present with obstruction require appropriate testing, starting with both flat and upright abdominal radiography.

On occasion, cases of diphyllobothriasis have been successfully identified by means of upper endoscopy or capsule endoscopy. [25, 26, 2]