Cysticercosis - Taenia Solium
- Diagnosis
- Background
- Lab Tests
- References
- Related Topics
Indications for Testing
- Seizures, hydrocephalus not caused by common etiologies
- Calcitic cysts on CT
Criteria for Diagnosis
- Proposed diagnostic criteria for human cysticercosis
- Absolute criteria
- Demonstration of cysticerci by histologic or microscopic examination of biopsy materials
- Visualization of the parasite in the eye by funduscopy
- Neuroradiologic demonstration of cystic lesions containing a characteristic scolex
- Major criteria
- Neuroradiologic lesions suggestive of neurocysticercosis
- Demonstration of antibodies to cysticerci in serum by enzyme-linked immunoelectrotransfer blot
- Resolution of intracranial cystic lesions spontaneously or after therapy with albendazole or praziquantel alone
- Minor criteria
- Lesions compatible with neurocysticercosis detected by neuroimaging studies
- Clinical manifestations suggestive of neurocysticercosis
- Demonstration of antibodies to cysticerci or cysticercal antigen in CSF by ELISA
- Evidence of cysticercosis outside the CNS (eg, cigar-shaped soft-tissue calcifications)
- Epidemiologic criteria
- Residence in a cysticercosis-endemic area
- Frequent travel to a cysticercosis-endemic area
- Household contact with an individual infected with Taenia solium
- Key for diagnostic interpretation
- Confirmation
- 1 absolute criteria
- 2 major, 1 minor, and 1 epidemiologic criteria
- Probable
- 1 major and 2 minor
- 1 major, 1 minor, and 1 epidemiologic
- 3 minor and 1 epidemiologic
- Confirmation
- Absolute criteria
Laboratory Testing
- CDC cysticercosis resources for health professionals and diagnosis recommendations
- Testing for consensus criteria
- CSF antibody by ELISA with confirmation by Western blot
- Serology – limited diagnostic use as a single test (variable sensitivity/specificity)
- May be useful if used with imaging data
- ELISA as initial testing in either serum or CSF
- Confirm ELISA with Western blot – more sensitive (available at some laboratories; not currently available at ARUP Laboratories)
- May be useful if used with imaging data
Imaging Studies
- Diagnosis is most often made by MRI or CT brain scans; addition of serologic screening by ELISA with confirmation by Western blot increases sensitivity of diagnosis of cysticercosis
- CT scan – high sensitivity and specificity; lower for ventricular or cisternal forms
- Single or multiple rounded lesions of low density with a small hyperdense mural nodule representing the scolex (starry night appearance)
- MRI – more sensitive than CT; much more expensive
- CT scan – high sensitivity and specificity; lower for ventricular or cisternal forms
Differential Diagnosis
- Vasculitis
- Central nervous system tumor
- Seizure disorders
- Stroke
- Infection
- Mycobacterium tuberculosis (TB)
- Fungal agents
- Toxoplasma gondii
- Brain abscess
- Nocardia spp
- Encephalitis
- Meningitis
- Connective tissue diseases
- Other
Cysticercosis is a parasitic infection caused by the larval stage of the pork tapeworm, Taenia solium.
Epidemiology
- Incidence
- Endemic in Mexico, Central and South America
- Etiological agent in 10% of new onset seizures
- Sex – M:F equal
Organism
- Humans can be definitive host (adult worm in intestine) or dead-end intermediate host (cysticercosis)
- Humans are incidental hosts by contact with contaminated water or undercooked pork
- Human disease depends on site of infection
- Tapeworm in intestine
- Larval forms in tissues
- Symptoms begin when cyst dies; depends on where the cysts are located
- Dying cyst releases antigenic material, triggering the host inflammatory response
Clinical Presentation
- Initial infection often asymptomatic
- Rapid onset dependent on number of cysts and body site affected
- Parenchymal
- Most common form
- Enhancing lesions
- Often asymptomatic – found incidentally during imaging
- Seizures
- Extraparenchymal
- Intraventricular or subarachnoid space disease
- Obstructive hydrocephalus
- Subarachnoid disease – stroke, vasculitis, meningitis/encephalitis
- Ocular cysts
- Usually vitreous; can be subretinal
- Blurry or disturbed vision, swelling or retinal detachment
Cysticercosis Antibody, IgG by ELISA 0055284
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Detect presence of IgG antibodies to T. solium in serum when a clinical suspicion of cysticercosis exists
Most sensitive in disseminated disease
Due to the cross-reactivity that exists between cysticercosis and echinococcus antibodies (approximately 23%) a positive result by ELISA should be confirmed by Western blot
CT or MRI suggested for neurologic presentations of the disease
Cysticercosis Antibody, IgG by ELISA (CSF) 0055285
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Detect the presence of CSF IgG antibodies to T. solium when a clinical suspicion of cysticercosis exists
Diagnosis of central nervous system infections can be accomplished by demonstrating the presence of intrathecally-produced specific antibody
Interpretation of results may be complicated by low antibody levels found in CSF, passive transfer of antibody from blood, and contamination via bloody taps
CT or MRI suggested for neurologic presentations of the disease
General References
Brunetti E, White C. Cestode infestations: hydatid disease and cysticercosis. Infect Dis Clin North Am. 2012; 26(2): 421-35. PubMed
Del Brutto OH. Neurocysticercosis: a review. ScientificWorldJournal. 2012; 2012: 159821. PubMed
Kraft R. Cysticercosis: an emerging parasitic disease. Am Fam Physician. 2007; 76(1): 91-6. PubMed
Ramírez-Zamora A, Alarcón T. Management of neurocysticercosis. Neurol Res. 2010; 32(3): 229-37. PubMed
Sinha S, Sharma BS. Neurocysticercosis: a review of current status and management. J Clin Neurosci. 2009; 16(7): 867-76. PubMed
Sotelo J. Clinical manifestations, diagnosis, and treatment of neurocysticercosis. Curr Neurol Neurosci Rep. 2011; 11(6): 529-35. PubMed
Medical Reviewers
Last Update: September 2016
