Taeniasis

Taeniasis is an intestinal infestation caused by adult tapeworms of the genus Taenia, most commonly Taenia saginata (beef tapeworm) and Taenia solium (pork tapeworm). A related species, Taenia asiatica, occurs in some regions. Humans are the definitive hosts, acquiring infection by eating undercooked or raw meat containing cysticerci, the larval stage in the muscles of cattle or pigs.

In the life cycle, cysticerci in meat are ingested and develop into adult tapeworms in the small intestine. The mature worm releases eggs and gravid proglottids, which pass in feces and can contaminate the environment. Cattle or pigs acquire infection by ingesting eggs and develop cysticerci in muscle. Eggs of T. saginata and T. solium are indistinguishable under routine microscopy.

Most infections are asymptomatic or cause mild abdominal symptoms such as discomfort or nausea. Diagnosis is usually by finding Taenia eggs or gravid proglottids in stool, or by identifying proglottids in the perianal area. Species identification may require proglottid characteristics or molecular tests, since eggs are not reliably differentiated by routine microscopy.

Treatment typically consists of a single dose of praziquantel or niclosamide. Follow-up stool testing confirms cure. In T. solium–endemic areas, cysticercosis can occur from ingesting eggs, which requires separate management.

Taeniasis occurs worldwide, with higher prevalence in regions where raw or undercooked pork or beef is eaten and where meat inspection and sanitation are limited. Prevention focuses on thoroughly cooking meat, proper meat inspection, sanitary waste disposal, and good hand hygiene to reduce transmission.