• foodborne infection
• low pathogenicity with adult tapeworm
• high pathogenicity with larval tapeworm

• adult
  • beef (Taenia saginata)
  • pork (Taenia solium)
  • fish (Diphyllobothrium latam)
• larval
  • neurocysticercosis (Taenia solium)
  • hydatid cyst (Enchinococcus granulosis)

• worldwide esp. East Africa (Ethiopia)
• usually asymp.

• epidemiology- worldwide esp. Mexico, Central America, South America, China, Indonesia, Tanzania
• usually asymptomatic

1. cow ingest embryonated eggs, hatch, oncospheres migrate to tissue and dev. to cysticerci
2. cysticerci ingested with raw or undercooked beef
3. cysticerci in muscle tissue
4. cysticerci released from muscle into stomach
5. worms mature and live in small intestines
   1. attach to wall with 4 suckers via scholex
6. adults grow
7. proglottis pass in feces

• definitive host: human
• intermediate host: pig
• life span: 25 yrs

1. cysteria ingested in raw or undercooked pork
2. cysticerci in muscle tissue
3. cysticerci released from muscle in stomach
4. adults mature and attach'live in small intestines via scolex (hooklets, 4 suckers)
5. adults grwo into gravid proglottidis
6. proglottis pass into feces

• space ocupying lesions
• as cysticerus dies, it elicits infammatory response
• inflammatory response sets of seizures

• mass effect
• inflammatory response
• obstruction of foramina and ventricular system of brain

• multiple lesions with increased intracranial P
• encephalitis
• arachnoiditis
• hydrocephalus
• CT scan: solitary ring enhancing lesion in cortex or gray-white matter junction

• depends on if the cyst is "dead"
• single ring enhancing lesion may resolve spontaneously (cysticerusis already dying)
• give azole or praziquantel for multiple cysts or cysts without ring enhancement
• steroids during larvicial therapy

• characteristic CT or MRI finding
• positive serology

• epidemiology
  • int hosts: copepod, freshwater fish
• distribution
  • Alaska and Canada among Native Americans
  • Great Lakes region
  • Finland and elsewhere in Scandinavia

• abdominal pain
• can take up vitamine B12 leading to a pernicous anemia and megaloblastic anemia

• Enchinococcus granulosus- unilocular hydatid
• E. multilocularis- alveolar or multilocular hydatid
• E vogeli and E oligarthus- polycystic hydatid

1. adult worm lives in sheep dog small intestins
   • sheep ingest eggs and develops in liver
2. eggs are ingested
3. oncospheres hatch in small intestins
4. oncospheres enter bloodstream, penetrate tissue
5. cyst develops in liver or in another organ
   1. also you can have cysts in brain and lung

• China
• Africa
• Southern hemisphere

although worldwide

• space occupying lesion
  • cysts can grow to larg size
  • golf ball size common
  • soccer ball not uncommon
  • can be fatal
• cysts in many location
• leakage of hyatid fluid leads to metastatis, anaphylaxis, eosinophilia

• slow growing cystic tumor
• history of residence in endemic area
• imaging via X ray, ultrasound, CT scan, MRI where CNS involvement
• serological tests
• surgery (protoscolex is diagnositic)

• puncture cyst
• aspiration
• injection of chemicals
• reaspiration

• regular de-worming of farm dogs
• removal of stray/feral dogs
• avoid feeding infected sheep meat to farm dogs
• enhanced personal hygiene