What is the pork tapeworm?Tapeworms live as parasites in the intestine of humans or other vertebrates. There are many different tapeworm species. Each species can cause different ailments, but only a few species can pose a danger to humans. In the picture, the head of a tapeworm. Click to enlarge.
Taenia solium is one of the most important representatives of tapeworms (cestodes). Cestodes belong to the worms (helminths). They colonize the intestine parasitic and have a white to yellowish color. The worms have a head called the scolex. This is equipped with suction cups and a hook chain.
A single pork tapeworm consists of several tapeworm limbs. Several thousand of these proglottids form a long chain. This necklace is also called Strobila. The pig tapeworms can thus reach a length between two millimeters and 20 meters.
The cestodes and thus the pork tapeworm belong to the endoparasites. Endoparasites are parasites that live inside the host. They do not have their own intestines, but absorb the nutrients from the digestive tract of the host. The recording takes place via the body surface. The outer skin layer of pork tapeworm is also called Tegument. It protects the worm from aggressive substances and at the same time serves to absorb nutrients.
The tapeworms grow by moulting. For this they reject the old Tegument and form a new skin.
Occurrence, distribution & characteristics
The pork tapeworm lives in humans as a parasite in the intestine. Infection occurs through consumption of meat contaminated with the pork tapeworm larvae. The infection cycle begins with the intake of tapeworm eggs by the pig. The eggs are excreted by other tapeworm carriers and come over the feces on pastures or on the pig feed.
In the small intestine of the pig larvae hatch from the tapeworm eggs. These drill through the intestinal wall and enter via the bloodstream into the muscles of the pig. There, the so-called Finns form. Finns are thin-walled bubbles that are filled with liquid. In the bladder are the head and neck of the future pork tapeworm. The pork tapeworm fins are also referred to as cysticerci. A single fin always contains only one tapeworm. The respective fins can become walnut-sized.
A special form of the pig fin is Cysticercus racemosus. It is a pig fins in a brain ventricle. This can even be 20 inches tall.
The pig serves the pork tapeworm as an intermediate host. Intermediate farmers include both domestic and wild boar. Man now picks up the tapeworm with infected meat. In the gut, the Finn's skin is digested from the pig's muscle, releasing the worm's head and neck. The tapeworm hooks then with its suction cups and its hook head in the mucous membrane of the small intestine and grows there. New tapeworm members are constantly forming.
The individual limbs gradually become sexually mature and are able to fertilize themselves. The last two limbs form eggs. They dissolve together with the eggs and are excreted with the chair. Each day, an infected person excretes up to nine tapeworm limbs, including eggs. Now get eggs in an intermediate host, then develop there again Finns. In humans, on the other hand, normally no Finns develop.
Diseases & complaints
Normally, the infection with a pork tapeworm goes unnoticed in an adult human. However, certain symptoms may occur. Maybe it comes to loss of appetite or nausea. Those affected can lose weight. Maybe they vomit too. If the pork tapeworm on the intestinal mucosa causes injuries that are associated with blood loss, anemia may also set in. The eggs that are excreted with the stool can cause an itch on the anus.
A lack of hygiene can lead to a serious self-infection. If the person scratched on the anus due to the itching, the worm eggs remain stuck under his fingernails. If it touches the facial area, the worm eggs can enter the mouth from their own digestive tract. This can cause a so-called cysticercosis. Cysticercosis refers to the infestation of humans with cysticerci, ie with the larvae of pork tapeworm.
In the Cysticercus cellulosus, numerous pea-sized fins form and settle at various points in the body. They can affect skeletal muscle, the eye, the skin and the central nervous system. When the skin and muscles are affected by the Finns, this is manifested by rheumatoid complaints. Nonspecific general symptoms such as headache or dizziness can also occur.
In a cysticercosis with Cysticercus racemosus, the fin vesicles in grape form. The individual collections can take on considerable proportions. When the central nervous system is affected, various neurological complaints may occur. Over the years, the individual bubbles can also calcify when the Finns die. These calcifications are also visible in the x-ray. Cysticercosis with Cysticercus racemosus often ends in death. In the blood, a cysticercosis manifests a so-called eosinophilia. The eosinophilic granulocytes are increasingly present in the blood serum.
The disease is diagnosed by serological detection by immunofluorescence tests, immunoblots or ELISA. Microscopic studies on tapeworms are also used. If cysticercosis is confirmed, an attempt is made to surgically isolate the larva. Supportive medicines such as anthelmintics and corticosteroids are used.
In order to prevent an infection with the pork tapeworm, it is recommended to either cook the pork or freeze it for at least one day at -20 ° Celsius. This kills the Finns in the flesh.