Trichuriasis etiology and pathology
Shape of adult trichuris parasitic worms is spindle, it like horsewhip. Male worms is long 30 ~ 45mm, large apparent later, the majority of curly, there is transfer of barbed end. This transfer can be hidden in a gill gill contraction intrathecal Peter, was the end of the sheath-shaped bulb, around which are fully covered with small thorns. Male long 35 ~ 50mm, blunt end of a round, rough gonopore is located in the middle most of the front-end, there are many small thorns around. The digestive system from mouth. Pharyngeal tube slender, rod-shaped body tube enveloping the outside. Village, the village of body cells by one-way. Rod is an active secretory cells, each rod-shaped cells have a pass into the pharynx open the lumen, the rod may be the existence of material from the cells to the pharyngeal lumen transit transport system. Although the function of rod-shaped body is not entirely clear, but some scholars have found that rod and esterase activity of protease, host cells can secrete digestive enzymes. Rod-shaped body is itself a matter of fact whipworm control of a group of pharyngeal gland. Pharyngeal tube connected with the intestine, the anus is located at the back-end body.
Trichuris parasitic worms Eggs is spindle, size (50 ~ 54) × (22 ~ 23) μm, in the vertical axis at the two ends of the nodules have a transparent, egg shell thickness, by the fat layer and the composition of the shell layer. Outer membrane protein was stained brown-yellow pigment, a transparent inner shell is true. Eggs in the egg cell containing small granules. From eggs to the body shell when the egg cell has not yet been split. Females lay eggs every day about 1000 ~ 7000. Eggs with the feces of patients with in vitro, in the outside temperature and humidity conditions for 3 to 5 weeks of infection period for egg development, it is swallowed by eggs contaminated food or water into the gastrointestinal tract, the infection period of egg larvae hatched in the small intestine, large intestine in the development of transitional to adult. General adult parasites in the caecum and appendix, and occasionally in other parts of the large intestine parasites. Insects into the head to the surface mucosa or submucosa, from the intestinal nutrition. Rough later in mesocaval most often free of. Ingestion of infection from egg to adult spawning period to be 1 to 3 months. Adult survival in the human body up to 5 years.
Adult trichuris parasitic worm's slender forelimb insert intestinal submucosa, intake of nutrition from tissue and blood, together with the secretions stimulate intestinal mucosa showed mild symptoms of inflammation or bleeding, can see that epithelial cells degeneration and necrosis. As a result of a small number of patients with intestinal inflammation, cell proliferation, intestinal wall thickening and the formation of granuloma. Some scholars have observed with 51Cr, whipworm measured each day so that the host blood loss of about 0.005ml. So in general do not have pots of blood in patients with symptoms. When severe infection (that is, more than 800 the number of parasites) Whipworm caused by chronic blood loss can lead to the occurrence of iron deficiency anemia. In addition, immunological studies have shown that human whipworm infection may have a certain immunity. The experimental results show that animals whipworm function of rod-shaped body is a major source of antigen.