Cysticercosis (Pork Tapeworm Infection) Treatment & Management

Asymptomatic cysticercosis: As mentioned above, more than 80% of patients with cysticercosis are asymptomatic. No evidence has shown that administering antiparasitic therapy for asymptomatic nonviable cysticercal lesions found incidentally in the brain is beneficial.

Patients who are found to have cysticerci only in subcutaneous or intramuscular sites generally do not require specific therapy.

If a single extracranial lesion is found, excision can be considered after neurocysticercosis is excluded with brain imaging.

Patients with ocular cysticercosis who have extraocular muscle involvement may present with diplopia and recurrent eye pain. Treatment with albendazole and corticosteroids has proven to be beneficial. Some patients may require surgical excision. For intraocular cysticerci, surgical removal is preferred over antiparasitic drug therapy. ^[20]

Patients with subcutaneous or intramuscular cysticercosis who develop symptoms due to inflammation can be treated with cysticerci excision or anti-inflammatory agents. Excision is the treatment of choice for a solitary symptomatic lesion.

Symptomatic therapy for neurocysticercosis should be the focus of initial and emergency management, as follows:

• Antiepileptic drug therapy in patients presenting with seizures
• Anti-inflammatory drugs such as corticosteroids and methotrexate in patients with cerebral edema or vasculitis
• Shunt surgery for hydrocephalus

Antiparasitic treatment is important but should never be considered emergently. Antiparasitic drugs can worsen cerebral edema and should be avoided in patients with increased intracranial pressure due to either diffuse cerebral edema or untreated hydrocephalus. ^[23]

Parenchymal cystic neurocysticercosis has better outcomes if treated with antiparasitic drugs along with corticosteroids. Treatment recommendations for parenchymal neurocysticercosis depend on its form, as follows ^[20] :

• In patients with untreated hydrocephalus or diffuse cerebral edema, management of elevated intracranial pressure alone is recommended.
• For viable parenchymal cysticercosis, antiparasitic drugs should be administered unless the intracranial pressure is increased. For 1-2 viable parenchymal cysts or a single enhancing lesion, monotherapy with albendazole is recommended. The usual dose is 15 mg/kg/day in 2 daily doses (up to 1200 mg/day) with food for 10-14 days.
• For more than two viable parenchymal cysts, a combination of albendazole (15 mg/kg/day in 2 daily doses up to 1200 mg/day) and praziquantel (15 mg/kg/day in 3 daily doses) for 10-14 days is recommended.
• Corticosteroids should be given whenever antiparasitic drugs are used.
• Antiepileptic drugs should be administered to all patients with seizures.
• Antiparasitic treatment is not recommended for calcified parenchymal neurocysticercosis.

Ventricular neurocysticercosis of the third and lateral ventricles should be treated with minimally invasive surgery, when possible. Adherent cysticerci should be managed with CSF diversion along with antiparasitic drugs. Minimally invasive and open craniotomies are options for fourth-ventricular disease. Antiparasitic drugs should be deferred until after surgical therapy. Treatment recommendations for extraparenchymal neurocysticercosis are as follows: ^[20]

• For intraventricular neurocysticercosis of the lateral and third ventricles, removal of the cysticerci via minimally invasive neuroendoscopy, when possible, is recommended over other surgical or medical approaches for cysticerci. Antiparasitic drugs should not be used preoperatively, since such treatment could result in disruption of parasite integrity, and an inflammatory response could prevent successful cyst removal.
• When surgical removal of fourth-ventricular cysticerci is possible, this is recommended over medical therapy and/or shunt surgery.
• When surgical removal is technically difficult, shunt surgery for hydrocephalus is suggested.
• For intraventricular neurocysticercosis, corticosteroid therapy is recommended to decrease brain edema perioperatively. Antiparasitic drug therapy along with corticosteroid therapy is suggested following shunt insertion to decrease subsequent shunt failure in patients in whom surgical removal of isolated intraventricular cysts is not possible.
• For subarachnoid cysts, antiparasitic drug therapy is recommended until radiologic resolution of viable cysticerci on MRI and resolution of other evidence of cysticerci.
• Methotrexate is suggested as a steroid-sparing agent in patients who require prolonged anti-inflammatory therapy.
• Shunt surgery in addition to medical therapy is recommended in patients with hydrocephalus due to subarachnoid neurocysticercosis. Some patients may benefit from surgical debulking over shunt surgery alone.
• For spinal neurocysticercosis, corticosteroid treatment is recommended in patients with evidence of spinal cord dysfunction, along with antiparasitic therapy.
• For intraocular cysticerci, surgical removal is preferred over antiparasitic drug therapy.

Consultation with a neurosurgeon is essential in patients with hydrocephalus, significant mass effect, or extraparenchymal CNS disease.

Consultation with a neurologist is needed if protracted or refractory seizures occur.

Consultation with an infectious disease specialist is recommended if active disease is suspected.

An ophthalmologist should be consulted for patients with ocular neurocysticercosis. At a minimum, a funduscopic examination should be performed before the initiation of antiparasitic drug therapy.

No specific diet restriction is recommended.

Patients should avoid reinfection and reingestion of ova from original sources by observing the following guidelines:

• Inspection of pork for cysticerci, which are visible in raw meat ("measly meat")

• Freezing or adequately cooking meat to destroy cysticerci (Pickling and salting are inadequate.)

• Administering antiparasitic agents to pigs

• Good personal hygiene and hand-washing prior to food preparation

No activities are restricted if the patient is otherwise asymptomatic.

All patients who present with seizures should take seizure precautions. Patients with a history of seizures may have state-required restrictions on driving motor vehicles. Physicians may be responsible for informing patients about these restrictions.

Patients with hydrocephalus may have ataxia and may be at risk for falls.

Educate patients regarding routes of transmission of cysticerci ova.

Meat inspection has been effective at preventing transmission of tapeworms in developed countries but has been uniformly unsuccessful in developing countries. Thorough cooking of meat is a primary prevention measure. Freezing at -5°C for 4 days, -15°C for 3 days, or -24°C for 1 day kills the cysticerci. ^[24]

In areas of endemic cysticercosis, avoid undercooked pork to reduce the risk of intestinal infection.

Be vigilant about avoiding potential fecal-oral transmission to reduce the risk for neurocysticercosis while in endemic areas. Individuals traveling to such areas should observe the following guidelines:

• Eat only fruits and vegetables that you have peeled yourself.
• Thoroughly wash (with water from a clean source) all food prior to ingestion.
• Maintain good personal hygiene and wash hands prior to food preparation.

A combination of mass treatment for tapeworm carriage, mass treatment of pigs, and vaccination of pigs shows potential for interrupting transmission of T solium infection in endemic regions, as demonstrated in Peru. ^[25]

Mass chemotherapy has been used to interrupt transmission in some areas of endemic infection, but disease usually returns within a few years.

Mass anthelminthic therapy yields only limited success and may cause adverse neurologic events in individuals with undiagnosed neurocysticercosis who receive these drugs.

Consider identifying human carriers of tapeworms, possibly based on a history of proglottid passage, and instituting targeted treatment.

Serologic screening of the contacts of patients should also be considered in the management of cysticercosis, particularly in nonendemic countries when transmission may have occurred within a household (eg, via food prepared by a household worker from an endemic country).

Vaccines for prevention of cysticercosis have proven effective for other Taenia species and are in development for T solium.

Transmission of cysticercal infections to pigs can be prevented with the following measures:

Changing pig-raising practices in endemic areas by confining the animals and preventing them from roaming freely to avoid contact with infectious ova excreted in human feces

Improving sanitary conditions and proper disposal of human stool

Possibly vaccinating pigs (Preliminary studies suggest this may be feasible.)

The initial brain reimaging should be performed 2 months after therapy completion.

MRI should be repeated at least every 6 months until resolution of the cystic component. ^[20]

Parasite antigen levels typically fall by 3 months after successful treatment.

If the cysts are growing in the absence of therapy, antiparasitic therapy should be considered.

In patients with seizures due to neurocysticercosis without calcification, perform imaging studies every 3-6 months. If calcification develops, lifelong anticonvulsant therapy is indicated, and further imaging studies can be performed as needed.

Tapering and discontinuation of antiepileptic therapy can be considered in patients with few seizures prior to antiparasitic therapy, resolution of cystic lesions on imaging studies, and no seizures for 24 consecutive months. In patients with a single enhancing lesion and no risk factors for recurrence, antiepileptic drugs can be discontinued after resolution of cystic lesions. Risk factors for recurrent seizures include the following ^[20] :

• Calcifications on follow-up CT scanning
• Breakthrough seizures
• More than two seizures during the disease course

Patients with calcified lesions and a seizure disorder should be maintained on anticonvulsants indefinitely, and they should undergo imaging studies only as needed.

Monitor anticonvulsant serum levels to prevent toxicity.

ICU monitoring is necessary in patients with uncontrolled seizures, elevated ICP, or severe extraparenchymal disease.

If antiparasitic therapy is provided, patients should be hospitalized and monitored during the initial phase.

• As cysticerci die, neurologic symptoms may worsen because of an increased inflammatory response.
• Most symptoms associated with antiparasitic therapy develop within 3-5 days of beginning therapy.
• Antiparasitic therapy may then be completed in an outpatient setting.

Prior initiation of therapy with antiparasitic medications or corticosteroids, the following steps should be taken:

• Apply a purified protein derivative (PPD) skin test. Patients in whom the PPD result is positive should be treated with isoniazid along with pyridoxine (vitamin B6) for the duration of their steroid treatment.
• Because many patients with cysticercosis also have risk factors for strongyloidiasis, these patients should be treated with ivermectin (200 μg/kg administered in two single doses two weeks apart before steroids are initiated.
• An ophthalmologist should perform an eye examination to exclude ocular cysticercosis.

Discharge medications may include steroids, anticonvulsants, antiparasitics, and cimetidine.

The anticonvulsants carbamazepine and phenytoin are first-choice treatments.

Patients with extraparenchymal neurocysticercosis should be treated at hospitals with active neurosurgical and neurological services because emergency procedures such as shunt placement or ventriculostomy may be required in patients with worsening hydrocephalus.

Arrange transfer if the facility is unable to provide neurologic or neurosurgical care.