Sparganosis is a parasitic infection caused by the plerocercoid larvae of the genus Spirometra including S. mansoni, S. ranarum, S. mansonoides and S.
[7] Once a human becomes infected, the plerocercoid larvae migrate to a subcutaneous location, where they typically develop into a painful nodule.
Public health interventions should focus on water and dietary sanitation, as well as education about the disease in rural areas and discouragement of the use of poultices.
The destination of the larvae is often a tissue or muscle in the chest, abdominal wall, extremities, or scrotum, although other sites include the eyes, brain, urinary tract, pleura, pericardium, and spinal canal.
The early stages of disease in humans are often asymptomatic, but the spargana typically cause a painful inflammatory reaction in the tissues surrounding the subcutaneous site as they grow.
[11] In one case of brain infestation by Spirometra erinaceieuropaei, a man sought treatment for headaches, seizures, memory flashbacks and strange smells.
Magnetic resonance imaging (MRI) scans showed a cluster of rings, initially in the right medial temporal lobe, but moving over time to the other side of the brain.
Third, humans may acquire the infection by placing raw poultices of the second intermediate hosts on open wounds, lesions, or the eyes for medicinal or ritualistic reasons.
The anterior end can invaginate and bears suggestions of the sucking grooves that are present in the scolex of the mature worm.
[15] The adult Spirometra live in the small intestine of the definitive host—a dog, cat, raccoon, or other mammal—for up to 9 years, where they produce many eggs.
[7][8][14] When the host defecates, the unembryonated eggs leave the body in the feces and hatch when they reach fresh water.
[9] In theory, a pre-operative diagnosis could be made by identification of exposure history and a painful, migratory, subcutaneous nodule.
These findings led Song et al. to suggest that clinical history, ELISA, and either MRI or CT scans could be sufficient to make a sparganosis diagnosis.
[18] In one case cerebral sparganosis was not diagnosed for four years, during which scans showed a cluster of rings moving from the right to the left side of the brain; ultimately the worm was found on biopsy.
Public health strategies focusing on providing basic access to clean water may help to reduce future sparganosis infections.
As a result of these findings, Song et al. conclude that health education about sparganosis and the importance of food sanitation should be implemented in all rural endemic areas.
[18] It has been recommended that water consumed in endemic areas should be boiled or treated to prevent ingestion of Cyclops or Spirometra larvae.
Strategies should warn people against ingesting the raw flesh of the intermediate hosts, such as snakes and frogs, and against using them as poultices.
[1][9] DNA analysis of rare worms removed surgically can provide genome information to identify and characterise each parasite; treatments for the more common tapeworms can be cross-checked to see whether they are also likely to be effective against the species in question.