Cysticercosis

What is it?

Cysticercosis is an infection caused by the pork tapeworm, Taenia solium. Infection occurs when the tapeworm larvae enter the body and form cysticerci. When cysticerci are found in the brain, the condition is called neurocysticercosis.

What are the causes?

It is caused by accidentally swallowing the eggs of pork tapeworm. Once inside the stomach, the tapeworm egg hatches, penetrates the intestine, travels through the bloodstream and may develop into cysticerci in the muscles, brain, or eyes. Tapeworm eggs are also passed out in the faeces of a person who is infected. These tapeworm eggs are spread through food, water, or surfaces contaminated with faeces. This can happen by ingesting contaminated food or water, or putting contaminated fingers in the mouth. A person who has tapeworm infection can reinfect himself (autoinfection).

What are the symptoms?

Signs and symptoms depends on the location and number of cysticerci in the body. Neurocysticercosis (cysticerci in the brain or spinal cord):Symptoms of neurocysticercosis depend upon where and how many cysticerci (often called lesions) are there in the brain. Seizures, and headaches are the most common symptoms. However confusion, lack of attention, difficulty with balance and swelling of the brain (called hydrocephalus) may also occur. Symptoms can occur months to years after infection, usually when the cysts are in the process of dying. When this happens, the brain swells in response to the antigens released from the cysticerci. The pressure caused by swelling is what causes most of the symptoms of neurocysticercosis. Cysticerci in the muscles:Cysticerci in the muscles generally do not cause symptoms. However, these may be felt or seen as lumps under the skin in superficial muscles. Cysticerci in the eyes:Although rare, cysticerci may float in the eye and cause blurry or disturbed vision. Infection in the eyes may cause swelling or detachment of the retina.

What is the treatment?

Infections are generally treated with anti-parasitic drugs in combination with anti-inflammatory drugs. Surgery is sometimes necessary to treat cases in the eyes, cases that are not responsive to drug treatment, or to reduce brain edema (swelling). Not all cases of cysticercosis are treated.Often, the decision of whether or not to treat neurocysticercosis is based upon the number of lesions found and the symptoms. When only one lesion is found, often treatment is not given. If one has more than one lesion, specific anti-parasitic treatment is generally recommended.If the brain lesion is considered calcified (this means that a hard shell has formed around the tapeworm larvae), the cysticerci is considered dead and specific anti-parasitic treatment is not beneficial. As the cysticerci die, the lesion shrinks. The swelling goes down, and often symptoms (such as seizures) go away.

What is the prognosis?

Diagnosis can be difficult and may require several testing methods. The doctor asks about where one has travelled and eating habits. Diagnosis of neurocysticercosis is usually made by MRI or CT scans of the brain. Blood tests are available to look for antibodies against the cysticerci and may help diagnose an infection.

What are the prevention?

Avoid eating raw or undercooked pork and other meats Do not eat meat of pigs that are likely to be infected with the tapeworm Wash hands with soap and water after using the toilet and before handling food, especially when travelling in developing countries Wash and peel all raw vegetables and fruits before eating. Avoid food that may be contaminated with faeces Avoid soft drinks and ice cubes Boiled water is the safest option where the quality of drinking water is suspect

DoctorNDTV Team