While the health effects of human tapeworm infection, or taeniasis, are usually mild, there are some rare cases when the human health effects can become more serious. According to the Mayo Clinic, on rare occasions, the tapeworm infection can become invasive. An invasive infection means the infection has spread to the brain and other organs of the body. Taeniasis is a parasitic infection humans contract by eating contaminated, undercooked meat or by accidentally eating tapeworm eggs. This parasite is found worldwide and is very common, according to the Centers for Disease Control and Prevention.
Intestinal
According to the Mayo Clinic, the health effects from a tapeworm infection in the intestines are minimal. The National Institutes of Health reports that tapeworms grow from larvae to full-length worms in the intestines. The worm can reach up to 12 feet in length, causing mild intestinal problems. Common health effects of taeniasis, like weight-loss and diarrhea, usually go away with proper treatment. A tapeworm can cause more serious conditions, such as blockages in a bile duct, pancreatic duct or the appendix. A blockage of these areas can lead to impaired function or infection in the gastro-intestinal tract. These conditions may require treatment or surgery to correct, depending on how early the blockage or infection is caught.
Neurological
According to the National Institutes of Health, the pork species of tapeworm can move into the brain and central nervous system, causing a condition called neurocysticercosis. This rare, invasive infection may damage brain and nervous system tissue. The Mayo Clinic reports this condition may cause headaches, visual impairment and seizures. Other health effects from this type of tapeworm infection are dementia, meningitis, hydrocephalus and, in severe cases, death.
Other Organs
According to the Mayo Clinic, tapeworm larvae can move from the intestines to other areas of the body, causing lesions or cysts. These cysts can press on organs as they grow, effecting how the organ works. The tapeworm cyst can become so large that it ruptures the organ. When pressing on blood vessels, the tapeworm can impact the circulatory system. A cyst that presses on a blood vessel may prevent oxygen-rich blood from reaching organs fed by that vessel.
