II. Epidemiology

  1. Immigrants from Central America and South America comprise the greatest number of cases in the U.S.
  2. U.S. natives comprise 15% of Cysticercosis-related deaths

III. Pathophysiology: Tapeworm lifecycle and pathogenesis

  1. Pork Tapeworm infection (Taenia solium)
  2. Infection originates in pigs as Tapeworm larvae (cysts)
  3. Key points related to Cysticercosis pathogenesis
    1. Tapeworms cycle between human hosts and pigs
      1. Humans ingest Tapeworm cysts in undercooked pork
      2. Pigs ingest human feces with Tapeworm eggs
    2. Ingestion of cysts does not cause Cysticercosis
      1. Cyst ingestion allows Tapeworm development
      2. Ingested eggs are required for Cysticercosis
    3. Cysticercosis is a result of fecal-oral ingestion
      1. Cysticercosis is not due to eating undercooked pork
      2. Cysticercosis occurs from infected human feces
        1. Can infect vegetarians from unwashed fruit
  4. Humans ingest Tapeworm larvae with undercooked pork
    1. Larvae attach to human gut (via scolex, a hook-like head) and grow to adult Tapeworm
    2. Adult Tapeworm sheds egg bundles (proglottids)
    3. Proglottids passed into human stool
  5. Pigs ingest food contaminated with infected human stool
    1. Pigs ingest Tapeworm eggs (oncospheres)
    2. Eggs develop into Tapeworm larvae
    3. Larvae enter pig bloodstream
    4. Larvae invade pig tissues and develop into cysts
  6. Humans ingest food contaminated with infected stool
    1. Source: Ingested Tapeworm eggs
      1. Infected food handlers who do not wash hands
      2. Household contacts with Taenia solium infection increases transmission risk
      3. Fruit or vegetables with infected fertilizer
    2. Source: Autoinoculation
      1. Tapeworm eggs retrograde travel gut to Stomache
    3. Cysticercosis occurs in similar fashion as with pigs
      1. Ingested eggs develop into Tapeworm larvae
      2. Larvae travel via blood to tissue where they embed
      3. Larvae form cysts in brain, eyes, spine, and muscle

IV. Signs

  1. General
    1. Cysts (cysticerci) may be single or multiple (even hundreds)
    2. Cysts are initially asymptomatic for years
      1. Larvae in cysts are walled off from host response
    3. Cysts degenerate and cause severe inflammation
      1. Dying parasites as well as larval release causes host antigenic response
      2. Inflammation and edema (and in some cases, mass effect) result in symptoms
  2. Distribution
    1. Brain Parenchymal Neurocysticercosis (90% of cases)
      1. Seizures (most common, occuring in 50-80% of symptomatic patients)
        1. Del Brutto (1992) Neurology 42(2): 389-92 [PubMed]
      2. Headache
      3. Parkinsonism
      4. Encephalopathy (if numerous brain cysts)
      5. Obstructive Hydrocephalus (if ventricles involved, occurs in 20-30% of symptomatic patients)
      6. Chronic Meningitis (mass effect with large cysts)
      7. Cranial Nerve palsy (mass effect with large cysts)
      8. Radiculopathy (if spinal cord involved - uncommon)
      9. Garcia (2005) Lancet Neurol 4(10): 653-61 [PubMed]
    2. Skeletal muscle lesions
      1. Typically asymptomatic
    3. Subcutaneous lesions
      1. Typically asymptomatic
    4. Eye lesions (1-3% of cases)
      1. Ocular lesions (e.g. vitreous lesions)
      2. Extraocular muscle lesions

V. Imaging: CT Head or MRI Brain

  1. Diagnostic findings suggestive of Neurocysticercosis
    1. Single <2 cm lesion
    2. No midline shift
    3. Larval sucking parts (scolex) may be visible
  2. Differntiating cyst stage
    1. Viable non-degenerating cyst: Not contrast enhanced
    2. Degenerating cyst (symptomatic): Contrast-enhancing
    3. Old cysts: Calcified
  3. Differential diagnosis
    1. Tuberculosis
    2. Parasitic Brain Lesions (e.g. Toxoplasmosis)
    3. Brain Tumor
    4. Brain Abscess
  4. Other imaging modalities
    1. Consider MRI brain if CT non-diagnostic
    2. Ultrasound or CT are approriate to image eye

VI. Labs

  1. Cysticercal Antibody: Serum Enzyme-linked immunoblot assay
    1. Test Sensitivity: >65%
    2. Test Specificity: >67%
    3. Serum more accurate than CSF titers
  2. Biopsy of infected tissue

VII. Diagnostics

  1. Dilated Eye Exam if ocular involvement suspected

VIII. Management

  1. Precautions: Do not start treatment without consult
    1. Treatment is individualized by multiple factors
    2. Antiparasitic agents are not uniformly indicated
      1. Overwhelming host response could be devastating
      2. Use may risk morbidity or mortality in some cases
      3. Albendazole with Systemic Corticosteroids is typically used
    3. Consult infectious disease in nearly all cases
    4. Consult neurology and neurosurgery in CNS cases
  2. Skeletal muscle lesions
    1. No treatment unless painful
    2. Consider surgical excision
  3. Eye: Intraocular lesions
    1. Consult ophthalmology
    2. Surgical excision for intraocular lesions
  4. Eye: Extraocular muscle lesions
    1. Consult ophthalmology
    2. Surgical excision for intraocular lesions or
      1. Consider Albendazole with Corticosteroid
  5. Brain: Subarachnoid and intraventricular lesions
    1. Ventricular shunt placed if Hydrocephalus
    2. Surgical excision for most lesions or
      1. Consider Albendazole with Corticosteroid
  6. Brain: Parenchymal Neurocysticercosis
    1. Albendazole with Dexamethasone (preferred)
      1. Do not use in massive infection
      2. Not needed in calcified lesions
    2. Anticonvulsants if concurrent Seizures
      1. Phenytoin
      2. Carbamazepine

IX. Prognosis

  1. Brain Parenchymal disease with few cysts has better outcome than extraparenchymal involvement or presence of numerous cysts

X. Prevention

  1. See Prevention of Foodborne Illness
  2. Careful and frequent hand washing
  3. Wash raw fruits and vegetables before ingesting

XI. Resources

Images: Related links to external sites (from Bing)

Related Studies (from Trip Database) Open in New Window

Ontology: Cysticercosis (C0010678)

Definition (MSH) Infection with CYSTICERCUS, the larval form of the various tapeworms of the genus Taenia (usually T. solium in man). In humans they penetrate the intestinal wall and invade subcutaneous tissue, brain, eye, muscle, heart, liver, lung, and peritoneum. Brain involvement results in NEUROCYSTICERCOSIS.
Definition (MSHCZE) Onemocnění vyvolané přítomností cysticerků. U člověka ji může vyvolat Taenia solium. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ )
Definition (NCI) A parasitic infection caused by the larval form of Taenia solium. It is a disseminated infection affecting the central nervous system, subcutaneous tissues, lungs, heart and liver. The most serious complications result from infection of the brain parenchyma. Patients may develop seizures, hydrocephalus, encephalopathy and meningoencephalitis.
Concepts Disease or Syndrome (T047)
MSH D003551
ICD9 123.1
ICD10 B69 , B69.9
SnomedCT 187527007, 59051007, 105684008
LNC LA10450-7
English Cysticercoses, Cysticercosis, Cysticercosis, unspecified, [X]Cysticercosis, unspecified, cysticercosis, cysticercosis (diagnosis), Cystercercosis, Cysticercosis [Disease/Finding], cysticercoses, [X]Cysticercosis, unspecified (disorder), Cysticerciasis, Larval taeniasis, Larval tapeworm infection, Larval teniasis, Cysticercosis (disorder), Infection by tapeworm larvae (disorder), Infection by tapeworm larvae
Dutch cysticercose, Cysticercose, niet gespecificeerd, Cysticercose, Cysticercosis
Japanese 嚢虫症, ノウチュウショウ
Swedish Cysticerkos
Czech cysticerkóza, Cysticerkóza
Finnish Systiserkoosi
Russian TSISTITSERKOZ, ЦИСТИЦЕРКОЗ
German Zystizerkose, nicht naeher bezeichnet, Cysticercosis, Schweinebandwurmbefall, Zystizerkose
Korean 낭미충증, 상세불명의 낭미충증
Croatian CISTICERKOZA
Polish Cysticerkoza, Wągrzyca
Hungarian Cystircercosis, cysticercosis
Spanish [X]cisticercosis, no especificada, [X]cisticercosis, no especificada (trastorno), cisticercosis (trastorno), cisticercosis, infección por larvas de tenia (trastorno), infección por larvas de tenia, Cisticercosis
Norwegian Cysticerkose
French Cysticercose
Italian Cisticercosi
Portuguese Cisticercose

Ontology: Taenia solium (C0039251)

Definition (MSH) Species of tapeworm in the genus TAENIA, that infects swine. It is acquired by humans through the ingestion of cured or undercooked pork.
Concepts Eukaryote (T204)
MSH D041201
SnomedCT 264400005, 17966003, 17894007
LNC LP14847-5
English Taenia solium, Tenia solium, Tenia armata, Tenia dentata, pork tapeworm, Pork Tapeworms, Tapeworms, Pork, Taenia soliums, solium, Taenia, Pork Tapeworm, soliums, Taenia, solium taenia, tenia solium, taenia solium, tapeworm pork, Taenia solium Linnaeus, 1758, Tapeworm, Pork, pig tapeworm, Pork tapeworm, Cysticercus cellulosae, Pork bladder worm, Armed tapeworm, Taenia armata, Taenia dentata, Cysticercus cellulosae (organism), Taenia solium (organism)
Swedish Taenia solium
Czech tasemnice dlouhočlenná, Taenia solium
Finnish Taenia solium
Russian TSEPEN' SVINOI, ЦЕПЕНЬ СВИНОЙ
French Ténia du porc, Ténia armé, Taenia solium
Polish Tasiemiec uzbrojony
Japanese カギサナダ, 有鉤条虫
Norwegian Taenia solium, Svinebendelorm
Portuguese Tênia de Suínos, Taenia solium, Tênia de Carne Suína
Spanish Cysticercus celulosae (organismo), Cysticercus celulosae, Taenia solium (organismo), helminto de la vejiga porcina, tenia del cerdo, tenia solitaria, Taenia solium, Tenia del Cerdo
German Bandwurm, Schweine-, Schweinebandwurm, Taenia solium
Italian Taenia solium
Dutch Gewapende lintworm, Lintworm, gewapende, Lintworm, varkens-, Taenia solium, Varkenslintworm

Ontology: Neurocysticercosis (C0338437)

Definition (NCI) A parasitic infection with tapeworms of the genus Taenia affecting the brain. It is manifested with seizures and headaches.
Definition (MSH) Infection of the brain, spinal cord, or perimeningeal structures with the larval forms of the genus TAENIA (primarily T. solium in humans). Lesions formed by the organism are referred to as cysticerci. The infection may be subacute or chronic, and the severity of symptoms depends on the severity of the host immune response and the location and number of lesions. SEIZURES represent the most common clinical manifestation although focal neurologic deficits may occur. (From Joynt, Clinical Neurology, 1998, Ch27, pp46-50)
Concepts Disease or Syndrome (T047)
MSH D020019
ICD10 B69.0
SnomedCT 230215006, 187148002
English Cysticercosis of CNS, Neurocysticercosis, NEUROCYSTICERCOSIS, CYSTICERCOSIS CNS, CNS CYSTICERCOSIS, Brain Cysticercosis, Cysticercosis, Brain, Neurocysticercoses, Central Nervous System Cysticercosis, Cysticercosis, Central Nervous System, Neurocysticercosis [Disease/Finding], neurocysticercosis, cerebral cysticercosis, cestode infection cysticercosis central nervous system, Cysticercosis of central nervous system (diagnosis), Cerebral cysticercosis, Cysticercosis of central nervous system, Cerebral cysticercosis (disorder), Cysticercosis of central nervous system (disorder), brain; cysticercosis (etiology), brain; cysticercosis (manifestation), cerebral; cysticercosis (etiology), cerebral; cysticercosis (manifestation), cysticercosis; brain (etiology), cysticercosis; brain (manifestation), cysticercosis; cerebral (etiology), cysticercosis; cerebral (manifestation)
Portuguese Cisticercose Encefálica, Cisticercose Cerebral, Neurocisticercose, Cisticercose do Sistema Nervoso Central
Spanish Cisticercosis Encefálica, neurocisticercosis, Cisticercosis Cerebral, cisticercosis cerebral (trastorno), cisticercosis cerebral, cisticercosis del sistema nerviosa central (trastorno), cisticercosis del sistema nerviosa central, Neurocisticercosis, Cisticercosis del Sistema Nervioso Central
Swedish Neurocysticerkos
Japanese シンケイノウチュウショウ, 神経嚢虫症, 脳嚢虫症, 神経嚢尾虫症, 中枢神経系嚢尾虫症, 中枢神経系嚢虫症, 嚢尾虫症-中枢神経系, 嚢尾虫症-神経, 嚢尾虫症-脳, 嚢虫症-中枢神経系, 嚢虫症-神経, 嚢虫症-脳, 脳嚢尾虫症
Czech cysticercosis mozku, neurocysticercosis, Neurocysticerkóza, neurocysticerkóza, mozková cysticerkóza
Finnish Neurosystiserkoosi
Russian NEIROTSISTITSERKOZ, TSISTITSERKOZ GOLOVNOGO MOZGA, НЕЙРОЦИСТИЦЕРКОЗ, ЦИСТИЦЕРКОЗ ГОЛОВНОГО МОЗГА
Korean 중추신경계통의 낭미충증
Polish Wągrzyca mózgu, Wągrzyca układu nerwowego
Hungarian neurocysticercosis
Norwegian Nevrocysticerkose, Cysticerkose i sentralnervesystemet
Dutch cerebraal; cysticercose, cysticercose; cerebraal, cysticercose; hersenen, hersenen; cysticercose, Cysticercose van centraal zenuwstelsel, neurocysticercose, Centraalzenuwstelselcysticercose, Cysticercose van het centrale zenuwstelsel, Cysticercose, hersen-, Cysticercose, neuro-, Neurocysticercose
German Neurocysticercosis, Neurozystizerkose, Zystizerkose des Zentralnervensystems, Zystizerkose, Gehirn, Zentralnervensystem, Zystizerkose
French Cysticercose cérébrale, Cysticercose neurologique, Neurocysticercose, Cysticercose du SNC, Cysticercose du système nerveux central
Italian Neurocisticercosi

Ontology: Tenia solium infection (C0473878)

Concepts Disease or Syndrome (T047)
ICD9 123.0
ICD10 B68.0
SnomedCT 187147007, 44883008, 266160004, 240818004
English Intestinal taenia solium infec, Intestinal tenia solium infec, Intestinal tenia solium infection, Tenia solium infection, Tenia solium infection, intestinal form, Taenia solium taeniasis, Tenia solium teniasis, taeniasis solium (diagnosis), taeniasis solium, Taenia solium intestine, Pork tapeworm (infection), pork tapeworm, pork tapeworm infection, tapeworm pork, Tapeworm infection: [intestinal taenia solium] or [pork] (disorder), Taenia solium infection, intestinal form (disorder), Tapeworm infection: [intestinal taenia solium] or [pork], Intestinal taenia solium infection (diagnosis), intestinal infection taenia solium, Taenia solium infection, intestinal form, Infection by Taenia solium, Pork tapeworm infection, Taenia solium infection, Armed tapeworm infection, Intestinal taenia solium infection, Intestinal taenia solium infection (disorder), Taenia solium infection (disorder), Taenia; infestation, solium (intestinal form), Tenia; infestation, solium (intestinal form), infestation; Taenia, solium (intestinal form), infestation; Tenia, solium (intestinal form), infestation; pork tapeworm, infestation; tapeworm, pork, pork tapeworm; infection, pork tapeworm; infestation, solium; Taenia infection, solium; Tenia infection, tapeworm; infestation, pork tapeworm, Taenia solium infection, intestinal form (disorder) [Ambiguous], Pork tapeworm
Dutch Taenia solium-infectie, intestinale vorm, Taenia solium-infectie, varkenslintworminfectie, Taenia; infestatie, solium (intestinale vorm), infestatie; Taenia, solium (intestinale vorm), infestatie; lintworm, varken, infestatie; varkenslintworm, lintworm; infestatie, varkenslintworm, solium; Taenia-infectie, varkenslintworm; infectie, varkenslintworm; infestatie, Taeniasis door Taenia solium
French Infection à Taenia solium, forme intestinale, Infection à Taenia solium, Infection à cestodes porcins
German Schweinebandwurminfektion, Taenia solium-Infektion, intestinale Form, Taenia solium-Infektion, Befall durch Taenia solium
Italian Infezione da taenia solium, Infestazione da Tenia solium, forma intestinale, Infezione da tenia suina
Portuguese Infecção por Taenia solium, Forma intestinal da infecção por Taenia solium
Spanish Infección por la tenia del cerdo, Infección por Taenia solium, forma intestinal, Infección por tenia solium, infección por Taenia solium, forma intestinal (trastorno), infección por Taenia solium, forma intestinal, infección por la tenia de los cerdos, infección por Taenia solium (trastorno), infección por Taenia solium, forma intestinal (concepto no activo), infección por Taenia solium, infección por tenia solium, forma intestinal (trastorno), infección por tenia solium, forma intestinal, infección por tenia solium
Japanese 有鉤条虫感染, 腸管寄生有鉤条虫感染, ユウコウジョウチュウカンセン, チョウカンキセイユウコウジョウチュウカンセン
Czech Infekce prasečí tasemnicí, Intestinální forma infekce Taenia solium, Infekce Taenia solium
Korean 유구 조충증
Hungarian Sertés szalagférgesség fertőzés, Taenia solium fertőzés, Taenia solium fertőzés, intestinalis forma