Clinical History
Abdominal pain, nausea, epigastric fullness and vomiting.
Imaging Findings
The child, with a two months history of abdominal pain, nausea, epigastric fullness, and vomiting, reported passing active flat worms in his stool. He had recently consumed raw beef during a trip in Western Europe. He did not report either weight loss or increase of the amount of food ingested.
Laboratory examination revealed increased -globulins and eosinophilia. A Small Bowel Follow Through (SBFT) examination demonstrated the presence of a long, translucent filling defect in the intermediate ileal loop, a finding consistent with the presence of a tapeworm. The intestine of the parasite was filled with barium used to perform the examination. The diagnosis was confirmed by stool examination which showed the presence of scolices of taenia saginata.
Discussion
Tapeworms are the largest of the cestodes. The most common species of intestinal taenia usually found in humans are Taenia saginata and Taenia solium, which may be easily distinguished by the shape and structure of their segments (proglottids) but not by their image on an x-ray film. T. saginata is also known as the beef tapeworm and T. solium is called the pork tapeworm, because cattle and swine are the intermediate hosts, respectively. Humans are the definitive hosts for both parasites.
The life cycle is characterized by adult worms that occur in the small intestine of humans, and gravid proglottids that are passed with feces. These proglottids are ingested by cattle or swine. The hexacanth larvae inside the eggs hatch once the egg reaches the small intestine. Larvae penetrate the mucosa and go on to develop in to cysticerci in the animals’ muscles. Humans become infected when they eat raw or undercooked infected meat.
Adults and children with tapeworm (T. solium, pork tapeworm only) can, if appropriate hygiene is lacking, become self-infected by ingesting eggs from their tapeworm which were picked up on their hands while wiping or scratching the anus.
Additionally, these individuals can expose other individuals to T. solium eggs, usually via food handling. Ingested eggs hatch in the intestinal track and the larvae migrate through the tissues, where they encyst. If larvae migrate to the brain, they can cause seizures and other neurological problems. This condition is called cysticercosis. Rarely, worms may cause obstruction of the intestine.
Adequate cooking of meat destroys the tapeworm larvae and prevents infection by tapeworm. Good hygiene and hand washing after using the toilet prevent self-infection in a person already infected with tapeworms.
Tapeworms are treated with oral medications, usually in a single dose. The drug of choice for tapeworm infections is niclosamide. Praziquantel and albendazole can also be used.
Complete eradication of the tapeworm occurs following treatment although definitive diagnosis can be reached only with stool examination, barium studies can be important to confirm the clinical suspicion of tapeworm infection.
Differential Diagnosis List
Taenia saginata infestation.
Final Diagnosis
Taenia saginata infestation.
