Cysticercosis
Cysticercosis is an infectious disease caused by the parasitic pork tapeworm, Taenia solium. This condition arises when humans ingest the eggs of T. solium, often through contaminated foods that are improperly cooked or washed. Once ingested, the eggs hatch and the larvae can invade various tissues, primarily affecting the central nervous system, muscles, and eyes, leading to the formation of cysts. Cysticercosis is a significant contributor to epileptic seizures, particularly in developing countries, and while many cases are asymptomatic, it can result in serious health issues such as blindness, brain damage, and heart failure. Diagnosis can be complex and involves a combination of blood tests, imaging studies, and occasionally biopsies. Treatment typically requires a tailored approach that may include medications and, in severe cases, surgical intervention. Preventive measures focus on food safety, personal hygiene, and avoiding raw or undercooked pork. Public education plays a crucial role in reducing the incidence of this disease.
Cysticercosis
Anatomy or system affected: All
Definition
Cysticercosis is an infectious disease caused by the parasite Taenia solium, which is a pork tapeworm. This parasite invades the central nervous system and causes cysts to form in various parts of the body, including the eyes, muscles, brain, and nervous system. Cysticercosis is a major cause of epileptic seizures, especially in the developing world. Although the prognosis is usually good, cysticercosis can lead to serious consequences, including blindness, brain damage, and heart failure.
Causes
Cysticercosis is caused by ingestion of T. solium eggs, which are found in foods that have been contaminated or cooked improperly. Once consumed, the eggs hatch and their embryos penetrate the intestinal wall and enter the bloodstream.
Risk Factors
Risk factors for cysticercosis include eating meats, vegetables, or fruits that are contaminated with T. solium. Such contamination can occur if foods are not washed or cooked properly.
Symptoms
In many cases, cysticercosis does not produce symptoms. If the parasite invades muscle tissue, lumps may be visible beneath the skin. If the eyes are involved, symptoms may include blurred vision and detachment or swelling of the retina. If the disease invades the nervous system, it is often accompanied by seizures, headaches, brain swelling, and problems with balance.
Screening and Diagnosis
Establishing the diagnosis of cysticercosis can be challenging and requires various tests. Blood tests can be used to detect antibodies to T. solium. Imaging studies such as X rays, computed tomography, ultrasonography, and magnetic resonance imaging can aid in visualizing the cysts. Biopsies can be performed on infected tissue. Electroencephalographs are useful if seizures are present. A spinal tap (lumbar puncture) may be appropriate for some persons.
Treatment and Therapy
Consultation with an infectious disease specialist is highly recommended. Treatment should be tailored to each patient, based on multiple factors, including the symptoms, the stage of cyst development, and the site and quantity of cysts. Treatment may involve corticosteroids, anticonvulsant medications, and antiparasitic agents. Although antiparasitic agents are effective for expelling parasites, they may produce a reactive localized inflammation. Multiple courses of treatment may be needed to fully eliminate the cysts. If seizures are present, referral to a neurologist is helpful for determining appropriate therapy. In some cases, surgery or shunting may be needed.
Prevention and Outcomes
Public education is extremely important for preventing cysticercosis. One should properly handle and cook food; fruits and vegetables should be washed thoroughly. One should not consume raw or undercooked pork. The risk of person-to-person transmission can be reduced by exercising good personal hygiene, including frequent handwashing. No vaccine against T. solium infection is available.
Bibliography
Garcia, H. H., et al. “Taenia solium Cysticercosis.” The Lancet 16 (2003): 547-556.
Icon Group. Cysticercosis: Webster’s Timeline History,1909-2007. San Diego, Calif.: Author, 2009.
Penrith, M. L. “Cysticercosis Working Group in Eastern and Southern Africa.” Journal of the South African Veterinary Association 80 (2009): 206-207.
Roberts, Larry S., and John Janovy, Jr. Gerald D. Schmidt and Larry S. Roberts’ Foundations of Parasitology. 8th ed. Boston: McGraw-Hill, 2009.
Singh, Gagandeep, and Sudesh Prabhakar. “Taenia solium.” Cysticercosis: From Basic to Clinical Science. Cambridge, Mass.: CAB International North America, 2002.
World Health Organization. “Taeniasis/Cysticercosis.” Available at http://www.who.int/zoonoses/diseases/ taeniasis.