Types of human parasites

Parasites refer to lower organisms that are pathogenic. They can act as pathogens for humans or as vectors of disease transmission. Parasites mainly survive in the bodies of hosts, or by attaching themselves to the outside of the body to obtain nutrients from the host to maintain their survival, development and reproduction. As a parasite, it can also change the host's survival behavior at any time in order to achieve its own better reproduction and survival goals. We humans are living beings that can be defined at various levels, including biological, spiritual, and cultural. So are there parasites in our bodies?

Human parasites are parasites that use humans as hosts. They can be divided into two categories: internal parasites and external parasites. Most of them belong to protozoa, nematodes, flatworms, annelids and arthropods. In parasitology, protozoa are usually called protozoa, and nematodes and flatworms are collectively called helminthes. Most of the important types of internal parasites include protozoa, nematodes, trematodes and crimson worms.

Parasites are usually ingested. Some larval cysts are also distributed in the lungs, subcutaneous tissue, and even the brain and eyes. Parasites are harmful to the human body. They mostly cause damage to the body by robbing it of nutrients, causing inflammation, and blocking blood vessels. Most of them belong to protozoa, nematodes, flatworms, annelids and arthropods. In parasitology, protozoa are usually called protozoa, and nematodes and flatworms are collectively called helminthes. Most of the important types of internal parasites are included in the classes of protozoa, nematodes, trematodes and helminths.

Hookworm parasitism can cause long-term chronic blood loss in the human body, leading to anemia and anemia-related symptoms in patients. Hookworms are distributed worldwide, especially in tropical and subtropical regions, where infection is more common among the population. It is estimated that hookworm infection affects approximately 900 million people worldwide. In our country, hookworm disease is still one of the parasitic diseases that seriously endangers people's health.

The hookworms that parasitize the human body mainly include Ancylostoma duodenale Dubini (1843), also known as Ancylostoma duodenale, and Necator americanus Stiles (1902), also known as American hookworm. In addition, the Ceylon hookworm (Ancylostoma ceylanicumLoose, 1911), which occasionally parasitizes humans, is similarly harmful to the first two hookworms. The infective larvae of Ancylostoma caninum Ercolani (1859) and Aucylostoma braziliense Gomez de Faria (1910) can also invade the human body and cause cutaneous larva migrans (CLM). Because the larvae migrate in a winding manner, the rash appears in the form of creeping lines, so it is called creeping eruption. But the larvae cannot develop into adults.

The pathogenic effects of the two hookworm species are similar. The duodenal hookworm causes more dermatitis and the anemia caused by the adult worms is also more serious. It is also the main species that causes hookworm disease in infants. Therefore, the duodenal hookworm is more harmful to the human body than the American hookworm.

Whether clinical symptoms appear after human body is infected with hookworms is not only related to the number of hookworm larvae invading the skin and the number of adult worms parasitizing in the small intestine, but also closely related to the human body's health status, nutritional conditions and immunity. In some cases, although worm eggs are detected in the feces, there are no clinical symptoms, which is called hookworm infection. Some people, although the number of parasites is small, still show clinical symptoms and signs of varying degrees, which is called hookworm disease.

Hookworm disease is one of the most widely distributed parasitic diseases in the world and is prevalent in Europe, America, Africa and Asia.

Ancylostoma duodenale belongs to the temperate type, while Necator americanus belongs to the subtropical and tropical types.