Taenia solium - Clinical Manifestation, Complication, Prognosis, Treatment

Last Modified: January 27, 2023

Contents

Clinical Manifestations of Taenia solium

The two distinct clinical syndromes of Taenia solium in humans include intestinal taeniasis and cysticercosis caused by adult tapeworm and cysts respectively.

Intestinal taeniasis

is mostly asymptomatic
if symptoms are present, clinical syndromes are mild and non-specific
symptoms include- nausea, abdominal discomfort, unexplained weight loss, constant hunger, pain, indigestion
uncommon syndromes are fever, diarrhea, vomiting, appendicitis, and cholangitis
nausea and abdominal discomfort are the most common in the mornings
if proglottids crawl out of the anus during the day, it may cause psychological distress but are not a prominent feature

Image: adult *T. solium* (Source: planehealth)

Cysticercosis

a dangerous systemic infection with variable syndromes depending upon the site where the cysticerci are formed
cysticerci are most common in the subcutaneous and intermuscular tissues followed by the eye and then the brain
the incubation period is variable – ranging from 15 days to many years after infections

Muscular and subcutaneous cysticercosis

any muscle may be involved
most patients are asymptomatic including subcutaneous nodules
symptoms are seen in cases of acute myositis
muscular cysticercosis is often associated with neurocysticercosis

Ocular cysticercosis

cysticerci are present in the eye
occurs in about 20% of cases
Taenia solium cysts can be found in the vitreous, subretinal space, and conjunctiva
the syndrome may manifest as iritis, uveitis, and palpebral conjunctivitis
if cysts are present in subconjunctival or subretinal areas, slow-growing nodules are observed which are often confused with tumors
sometimes, subretinal cysts may lead to blindness due to detachment of the retina
a fundoscopic examination may reveal freely floating cysticerci in the vitreous chamber, and anterior chamber and can help in the morphology and identification of larval forms
subretinal tissues may also be infected with Taenia solium larvae

Neurocysticercosis (NCC)

the most serious form of cysticercosis
occurs in 60% to 90% of cysticercosis cases
the clinical manifestations depend upon the number, location, and viability of cysts, host response against cysts, and stage of development of cyst (young, mature, intact, or disintegrated)
the leading cause of adult-onset seizures with nearly 50% of patients with seizures having serological evidence of neurocysticercosis

NCC is of two types- Parenchymal and Extraparenchymal disease.

Parenchymal disease

caused by infection of the brain parenchyma with cysticerci
a most common form of Neurocysticercosis

Extra-parenchymal disease

caused by the location of Taenia solium cysts in cerebrospinal fluid (CSF) of the ventricles, cisterns, and subarachnoid space in the spinal cord
on average 1 to 5 cysts are found but in some cases, up to 200 cysts have been reported

Clinical syndromes of NCC, which may occur individually or combined, include convulsions and/or seizures, meningitis, intracranial hypertension, and psychiatric disturbances. These syndromes may be sudden or gradual in nature.

Convulsions and/or seizures

caused by the presence of cysts in the parenchyma of the brain
seizures are the most common symptoms (70% to 90% cases)
in children, seizures have an acute onset and are focal
in areas endemic to Taenia solium, it commonly manifests as epilepsy

Meningitis

Taenia solium cysts if present in the meninges may manifest as meningitis
the cysts if present in the intramedullary spinal cord can produce motor or sensory disorders

Intracranial hypertension

caused by obstruction of CSF by cysts in the ventricles of the brain
symptoms include vertigo, nausea, vomiting, headache, altered mental status

Complications of Taenia solium

Complications of Cysticercus cellulosae include stroke, intracranial herniations, and status epilepticus.

Prognosis of Taenia solium

The prognosis of intestinal taeniasis, Muscular and subcutaneous cysticercosis, and ocular cysticercosis is good while that of neurocysticercosis (NCC) is highly variable.

Nearly 10% of patients with cerebral lesions die within 5 to 10 years of illness.

Treatment of Taenia solium

drugs of choice include Praziquantel and niclosamide
the anti-parasite drug must be accompanied by purgatives to expel the dead tapeworm along with the feces as well as corticosteroids to reduce inflammation
since antihelminthic drugs can provoke irreversible drug-induced inflammation, surgery can be done for cysticercosis in the ocular, ventricular, and spinal cord