Worms are invertebrates that can live as parasites in the human body. Worm diseases, for example, can be caused by nematodes, sucking worms, or tapeworms.
What are worms?
Worms are the names given to numerous groups of invertebrates, many of which are only slightly related. Worms are among the parasites of humans. When they enter the body, they can cause a variety of diseases and associated symptoms. The extent of the disease symptoms depends both on the type of worm and on the immune system of the person affected. Many worm diseases occur primarily in subtropical or tropical areas. However, some worm species are also native to Germany. In humans, most worm diseases affect the intestine. Thus, the fish tapeworm, the cattle tapeworm and the pork tapeworm can cause intestinal diseases in humans. Dog and fox tapeworm, on the other hand, preferentially affect the liver or lungs. Children are frequently infected by pinworms. Roundworm infections can also occur.
Occurrence, distribution, and characteristics
Tapeworms belong to the class of flatworms. There are more than 3000 species worldwide. The tapeworms live as so-called endoparasites in the brain and intestine of vertebrates. They attach themselves to the intestinal wall with the help of suction cups and hooked rings. Parts of the worms are excreted in the feces. The feces are one of the sources of infection for tapeworms. Infestations can also result in constantly recurring self-infections if hygiene is poor. However, the worms usually enter the human body through contaminated food. The eggs of the dog or fox tapeworm are also ingested via contaminated food. The eggs are often found on wild berries. Pinworms are usually transmitted by smear infection. The worm eggs are picked up, for example, by touching contaminated toys or toilet door handles. Widespread pinworm infestation occurs regularly, especially in daycare centers or kindergartens. Infection with roundworms usually occurs through inhalation of dust containing feces or through consumption of lettuce or vegetables that have been fertilized with contaminated excreta. Trichinae enter the human body through contaminated meat. Pork is usually the cause of what is known as trichinellosis. Whipworms, also enter the body via raw food contaminated with excreta. Hookworms occur almost exclusively in the tropics and subtropics. They bore through the skin. Vacationers become infected, for example, by walking barefoot on the beach. Like hookworm disease (ankylostomiasis), schistosomiasis is a disease of the tropics and subtropics. The larvae of the worms swim in the water and enter the human body through the skin when they come into contact with water.
Diseases and symptoms
Tapeworm disease is often asymptomatic. The worms do not cause pain as long as they remain in the intestine. However, the parasitism of the worms may cause unwanted weight loss. Deficiency symptoms due to the loss of nutrients are also possible. If the worm eggs are reabsorbed orally from the patient’s own feces through smear infections, larvae develop. These are able to penetrate the intestinal wall. They spread throughout the body via the bloodstream. They can settle in the connective tissue, in the muscles or in the brain and thus, depending on the localization, cause various symptoms such as cramps or neurological disorders. In echinococcosis, infection with the fox or dog tapeworm, the eggs of the worms mainly reach the lungs and liver. Here, the eggs join together in a large aggregate and form cysts. These result in destruction of the surrounding tissue. The cysts grow over months and years. This severely impairs the functionality of the affected organ. The cysts can also burst open. When the contents of the cysts empty into the body, severe inflammation or pronounced allergic reactions may develop. A characteristic feature of an infection with pinworms (oxyuriasis) is an unpleasant itching sensation at the anus. Most often, children are affected by the infection. They scratch their anus and then often reabsorb the eggs through the mouth. In girls, vaginal infections can also develop as a result of the scratching.Nighttime itching is often the cause of sleep disturbances in children. When roundworms (ascariasis) enter the body through the lungs, they cause bronchitis-like symptoms. The adult worms cause pain and digestive discomfort in the gastrointestinal tract. Trichinae enter the bloodstream via the bloodstream from the intestines. The further development of the ingested larvae takes place in the skeletal muscles. The parasites preferentially infect the neck, masticatory and diaphragm muscles. The muscles of the shoulder girdle are also frequently affected in trichinellosis. The muscles are damaged by the larvae. The consequences are fever and rheumatic pain. The face may swell due to allergic reactions. Infestation of the tongue may cause speech difficulties. Infestation of the diaphragm, on the other hand, leads to breathing difficulties. Hookworms settle in the small intestine after piercing the skin. Hookworm disease (ankylostomiasis) is usually chronic. Because the worms actively suck blood from the intestinal wall, anemia can develop. Affected persons are tired, weary and pale. The iron levels in the blood are lowered. Couple flukes preferentially settle in the urinary bladder, intestines, liver, lungs and brain. Liver swelling, headache, acute fever, and life-threatening bleeding in the stomach and esophagus are possible symptoms of such schistosomiasis.
