Fast Five Quiz: Are You Prepared to Confront Parasitic Infections?

Michael Stuart Bronze, MD


June 29, 2017

Endoscopic retrograde cholangiopancreatography has become a commonly used procedure for both diagnosis of ascariasis and removal of worms from the biliary tract. The ease of diagnosis and therapy in the same setting makes this test particularly valuable when used with real-time ultrasonography. The combined procedures yield a sensitivity of nearly 100%.

Serologic tests are not clinically useful for the diagnosis of ascariasis. Stool examination for ova and parasites usually discloses large, brown 60 µm x 50 µm trilayered eggs in persons with ascariasis. However, stool examination may be negative for ova for up to 40 days after infection. This is due to the time needed for the migration and maturation of the worms. The outer surfaces of fertilized eggs have an uneven mucopolysaccharide coat.

Chest x-rays may show fleeting opacities during pulmonary migration. Abdominal x-rays may show a whirlpool pattern of intraluminal worms. Narrow-based air fluid levels without distended loops of bowel on upright plain films suggest partial obstruction. Wide-based air fluid levels with distended loops of bowel suggest complete obstruction.

For more on the workup of ascariasis, read here.


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