دکتر عباسعلی اسکندریان بسمه تعالی دانشگاه علوم پزشکی اصفهان – دانشکده پزشکی – گروه انگل شناسی و قارچ شناسی راسته تریکوراتا Order :Trichurata دکتر عباسعلی اسکندریان

راسته تریکوراتا: Order Trichurata تمام اعضای این راسته دارای سلولهای مشخصی در ناحیه مری بنام سلول های استیکوسیت هستند از نظر اندازه به دو دسته : 1- کاملا ماکروسکوپی (3-5 س X 1 س)، بدن دارای دو قسمت متمایز و نامتناسب از نظر ضخامت: خانواده تریکوریده – جنس: تریکوریس، تنها گونه انسانی:Trichuris trichiura (Trichocephal) X 25 2- کاملا میکروسکوپی (1000 میکرون× 40 میکرون)، طول بدن تقریبا ضخامت یکسان دارند X 1000 خانواده های: تریشینلیده Family Trichinellidae Genus: Trichinella T.spiralis و کاپیلاریا Family Capilaridae C. philipinensis C. hepatica

Family Trichuridae - Whipworms Morphology : thick relatively short, posterior end with long thread - like anterior end, whip like in appearance (Trichocephalus) thread-head used in some texts.

Trichuris trichuria Whipworm Definitive Host: Humans Dogs possibly Intermediate Host: None Pigs and chickens are transport hosts Flies will transport eggs on legs Geographic distribution: Cosmopolitan, including southern U.S. Warm Climate High rainfall Unsanitary conditions Eggs have been found in a glacier mummy over 5000 years old. Probably evolved with us as we split from our common ancestor with the chimps. 30-50 mm long Prevalence in the southeaster U.S. can reach 20-25%, mainly in children. Overall prevalence in the U.S. is 1.2%. World wide, probably around 902 million people.

Trichuris trichuria Location: large intestine from cecum and appendix to rectum Burrows head into mucosa Transmission: Ingestion of embryonated eggs, usually in contaminated food Requires high humid, warm climate and shade to develop properly. Embryonation takes about 21 days. Eggs can be ingested in dirt, which is a common practice in some areas (and a pastime of many small children).

تریکوسفال نر 20×

کرم های تریکوسفال نر و ماده

Life Cycle of Trichuris trichiura Adults in large intestines Eggs go out in feces Embryonate in soil Eggs eaten by humans Emerge into lumen Juvenile penetrate mucosa Juvenile mature Eggs hatch Eggs are not infective until they embryonate in the soil so no autoinfections. Juvenile invades a cell in the mucosa and molt four times to mature. Then they poke their posterior ends out of the cell and leave their heads burrowed in mucosa.

Diagnosis and Prevention Diagnosis - presence of egg or worm in stool These are easy to distinguish Prevention Proper sanitation in feces disposed and hand washing Trichuris vulpis common whipworm of dogs of this area. It can infect humans.

Trichuris trichiura Diagnosis: bipolar eggs in feces. Colonoscopy can also uncover worm infections Treatment: Mebendazole or albendazole. Rectal prolapse treated with surgery The large intestine is a difficult place to treat orally but these drugs work. Training children and adults how to avoid infections is also important.

Pathology Usually asymptomatic if few worms. (<100) Heavy infection variety of symptoms. anemia - hemorrhage of digestive tract secondary bacterial infection Prolapse rectum possible cause of appendicitis

Trichuris trichiura Pathology and Symptoms: Low-level infections (<100 worms) are asymptomatic Large infections can result in diarrhea, bloody stool, abdominal pain and rectal prolapse Chronic infections in children can lead to growth retardation and finger and toe clubbing. Often associated with Ascaris lumbricoides infections. Mode of transmission same Finger and toe clubbing is an odd thickening of the ends of the digits. The mechanisms in unclear but it is a signal of chronic whipworm infections. Worms feeds on cells of the mucosa and submucosa and blood but blood loss is neglible. Trauma to intestinal lining can result in hemorrhaging resulting in anemia. Some of the damage is due to the inflammatory response of the body to the worm.

Epidemiology Poor sanitation-human feces deposited in soil Physical conditions allowing worm development in soil warm climate high rainfall high humidity moisture retaining soil (clay soil) shade