Cysticercosis: Causes, Symptoms, Treatment, Prevention

Cysticercosis is a common infection of tissue that is caused by pork tapeworm when it is in the young form. It is not necessarily associated with occurrence of any symptoms in the body. Cysticercosis can lead to developments of the lumps under the skin. They usually vary from 1 to 2 cm in size. These lumps may not cause any problems for months or even years. Ultimately, they can swell up and become painful before getting normal when larvae grows and dies. Neuro-cysticercosis is a special case of cysticercosis that cause infection in brain leading to neurological symptoms. It is one of the most common type of infections among people in developing countries.

Cysticercosis in human beings is caused due to pork tapeworm, also known as Taenia solium or T. solium. It enters into the human body in the form of eggs that can enter into the body through contaminated vegetables, food or water. The eggs of the pork tapeworm settles, hatch and develop into larvae in the intestine. The small larvae now moves from the intestine to different muscles via blood stream. These small larvae further develops into fully grown larvae over a time duration of 2 months and is known as cysticerci. The larvae has a oval and can grow into a size of 0.6 to 1.8 cm in its fully grown form. It has a semitransparent appearance.

The human cysticercosis is caused when the muscle get infected by the larvae of the pork tapeworm that enters into the body through infected food or water.

The pork tapeworm enters into the body through the oral-fecal route.

Taeniasis is a common infection in human beings caused by the infection due to various types of parasites including Taenia solium (pork tapeworm), Taenia asiatica (Asian tapeworm) and Taenia saginata (beef tapeworm). These parasites enter into the human body when pork or beef is not cooked properly before eating.

Cysticercus Cellulosae refers to the larvae of the tapeworm Taenia solium, which is found in the pork.

The worm that causes cysticercosis can effect muscles in different parts of the body. The signs and symptoms of cysticercosis depends on the location of the body that is affected.

• Infection in voluntary muscles. Cysticercosis that occurs in any of the voluntary muscles can lead to fever, myositis, muscular pseudohypertrophy and eosinophilia. The symptoms begin with swelling in muscles and can quickly develop into fibrosis and atrophy. However, the symptoms usually do not show up in most of the cases.
• Infection in nervous system. When the formation of the cysticercosis causing cyst takes place in parenchyma of brain, it is called as neurocysticercosis. In this type of cysticercosis, the person can experience light headache. Other common symptoms include nausea and feeling of vomiting.
• Infection in eyes. Cysticercosis can also affect muscles of eyes including extraocular muscles, globe and conjunctiva. This type of infection can result in retinal edema, partial or complete loss of vision, hemorrhage and other eye problems.

Some other common symptoms of cysticercosis include weakness, swelling and lethargy in body.

The traditional methods of diagnosing any case of cysticercosis involves analysis of stool samples to look for the eggs of the pork tapeworm or identifying the presence of tapeworm during its growing stages. However, the presence of the tapeworm in stool can be observed in only a few cases. Thus, it is not an efficient test for detecting the case of cysticercosis. A special case of cysticercosis called as Ophthalmic cysticercosis can be detected rather easily by looking for the presence of the parasite in the eye via fundoscopy.

A more effective diagnosis method of cysticercosis is the use of biopsy of the tissue that is infected through advanced lab instruments. Various laboratory tests used for the diagnosis of Cysticercosis include diagnose only taeniasis and not cysticercosis, Taenia solium eggs, proglottids found in feces etc. Modern tests for detecting cysticercosis include some common radiological tests such as CT scans and X-ray that look for the presence of “ring-enhancing brain lesions”. MRI can also be used as an effecting detection method. The larvae that have become dormant or calcified can be easily detected by X-ray techniques.

Advanced imaging techniques, MRI and CT scan are very effective in diagnosis of cysticercosis. They are capable of detecting cysts in all forms whether they are in active or inactive state, calcified or un-calcified form. However, cystic lesions that causes infection in ventricles of the brain can be difficult to identify even with CT scan as the density of the cyst fluid has the same density as that of cerebrospinal fluid. The cysts that are present outside the parenchyma in brain are easier to detect by looking at symptoms such as enhanced basilar meninges and hydrocephalus.

The treatment of cysticercosis depends on various factors such as the particular stage of the development of cyst and the tissue that is infected by the cyst.

The patients in which there are no symptoms of cysticercosis do not need any treatment. Anticonvulsant medications are used as the initial treatment option followed by anthelmintic treatments that can be started as soon as the seizures are controlled.

Anti-parasitic is used as the next treatment option after analyzing the stage of the cyst formation, number of cysts present and the part of the body that is infected by the cyst.

Anticonvulsants used for the treatment of cysticercosis are particularly helpful in reducing the chances of seizures by preventing cysts from growing and causing any further inflammation.

Medications can also be used effectively for the treatment of cysticercosis. Albendazole is a common drug that is commonly used and is available at a reasonable price. Complete removal of cyst requires more than one cycles of dosage. The combination of anti-parasitic medications and corticosteroids works well in restricting the inflammation from spreading. However, they are not very effective against the active parasites. Anticonvulsants are particularly used in such cases of cysticercosis that effect the tissues of the brain. Medications that are particularly effective in such situations include phenytoin (Dilantin) and carbamazepine (Tegretol).

Surgical treatments are usually not required in the treatment of cysticercosis. However, there are some particular cases such as racemose, spinal neurocysticercosis and intraventricular cysticercosis where surgical treatment becomes necessary.

The surgical treatment includes removal of the cyst from the infected ventricles by either carrying out the shunting process or using endoscopy. Cyst formation in the central nervous system usually gets severe and requires surgery to make sure that the increasing pressure in the brain is released timely by providing a brain shunt. Surgical treatment is also recommended in case of subcutaneous cysts to eliminate the symptoms associated with severe pain.

Cysticercosis can be prevented by avoiding the host where the parasite grows into larvae from egg and completes its lifecycle. The simplest way to avoid cysticercosis is to break the lifecycle and prevent it from causing any infection. Fortunately, there are just two hosts including pigs and human beings where this parasite can complete its lifecycle. Let us look at some of the simple ways by which cysticercosis can be prevented from occurring or spreading to other individuals.

• It is important to educate people about how parasites propagate from one host to another and make them aware of the importance of sanitation in controlling parasites from causing infectious diseases such as cysticercosis. When people will be aware of the lifecycle of the parasite, they can take necessary steps to break the lifecycle.
• Pork must be cooked nicely to kill all the eggs of the parasite or break the lifecycle of the parasite. Also, the pork must be stored in freezer.
• Pigs must be regularly monitored for any infections and also vaccinated timely to prevent the parasite from completing its lifecycle.
• Pigs must be kept away from human feces to make sure that parasites are not transmitted into the body of the pigs from faces. This can be done by restricting pigs to closed enclosures.

Cysticercosis may lead to one or more of the following complications:

• Partial or complete loss of vision.
• Increased pressure in the brain due to blockage of veins leading to accumulation of cerebrospinal fluids in brain.
• Cognitive problems.
• In extreme cases, it may also become life threatening.

Also Read:

• Neurocysticercosis: Causes, Symptoms, Treatment, Complications, Pathophysiology