Taenia solium “The Pork Tapeworm” Kingdom: Animalia Phylum: Platyhelminthes Class: Cestoda Order: Cyclophyllidea Family: Taeniidae Genus: Taenia Species: T. solium By: Christopher Ellis

What’s it do? Taenia solium causes two different diseases… 2.) taeniasis – digestive tract Develops when adult tapeworm infects human intestine 3-6 feet long Asymptomatic but continuous source of eggs in the feces 1.) cysticerosis – muscle tissues Eggs cross digestive tract, enter circulation, and lodge in muscle tissues If it’s in the brain it’s neurocysticerosis

Morphology Larvae Tapeworm Larvae enters body and forms… Taenia solium Morphology Larvae Tapeworm Larvae enters body and forms… cysticerci which are 6- 18mm wide by 4 - 6mm in length when found in the muscle tissue. Pig muscle infected with cysticerci However, it may also be found in other tissues such as in the C.N.S. where they may grow up to several cm in diameter!

Affects in the Human - Larva Taenia solium Affects in the Human - Larva Affects C.N.S. and brain Other Muscle Tissue severe pain, paralysis, and epileptic convulsions swelling of the brain (called hydrocephalus) May feel lumps Asymptomatic unless involving ocular tissue, then… loss of consciousness or even death! Great discomfort and possible detachment of retina The annual mortality rate is approximately 50,000 cases worldwide!

Eggs or gravid proglottids are passed through “feces” Taenia solium Life Cycle Eggs or gravid proglottids are passed through “feces” Pigs become infected by consuming infected eggs or gravid proglottids In the pig’s intestine, the oncosphere hatches The oncosphere invades the intestinal wall and migrates to the striated muscles, where they develop into cysticerci In the human intestine, the cysticercus develops over 2 months into an adult tapeworm, which can survive for years. The tapeworm attaches to the small intestine by their scolex.

Hosts to T. solium Humans are the only definitive host for Taenia solium Hosts to T. solium Humans are the only definitive host for T. solium (absolute host specifity).

Taenia solium Taenia solium eggs T. solium eggs

Intermediate Host - Pigs Taenia solium Intermediate Host - Pigs Intermediate Host (Pig) consumes infected eggs T. solium eggs

Definitive Host - Humans Taenia solium Definitive Host - Humans Definitive Host (Human) consumes infected pork (Measly) Pork is infected with tapeworm cysticerci Intermediate Host (Pig) consumes infected eggs T. solium eggs

Morphology Adults Taenia solium Rostellum (with roughly 30 hooks) The strobila consists of between 800 and 1000 proglottids. Rostellum (with roughly 30 hooks) The gravid proglottids are 12mm x 6mm each scolex Each proglottid may produce 50,000 eggs respectively! The adult tapeworms are around 10 feet, but may grow up to 27!

Life Cycle in the Human - Adults Taenia solium Life Cycle in the Human - Adults However, sometimes there are non-specific symptoms that form such as constipation or diarrhea. Occasionally, appendicitis can result from migrating proglottids. Very rarely is there perforation of the intestinal wall, but when it does occur it is called peritonitis. 25% of cysticercosis infections are aquired by the autoinfection.

Risk Factors 50,000 cases reported globally a year! Taenia solium Risk Factors 50,000 cases reported globally a year! However it is VERY rare in Islamic countries where there is little consumption of pork Poorer countries or more at risk for these parasites because they are in close contact with pigs and eat undercooked pork more often than developed countries. Latin American Countries especially are at high risk and experience many cases of pork tapeworms.

Taenia solium Prevention Try to keep stable, sanitary conditions in impoverished areas. Ensure that pork is cooked thoroughly before eaten. Don’t eat poop.

Diagnosis and Treatment Taenia solium Diagnosis and Treatment Diagnosis Cysticercosis - can appear from 10 days to 10 years after infection. Taeniasis - eggs occur in stool 8-12 weeks after infection. Stool samples can diagnose both cysticercosis and teniasis but is not possible during the first 3 months following infection. Treatment Treatment is simple and very effective.  Praziquantel is the drug of choice. Appropriate drug therapy seems to be the only treatment. There is no immunization available at this time.

Pictures Taenia solium bladderworm or cysticercus of Taenia solium. Contains hooks (Rostellum) bladderworm or cysticercus of Taenia solium.

Scolex of Taenia Solium More Pictures Taenia solium removed Scolex of Taenia Solium Taenia solium eggs