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 : 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 spiralis و کاپیلاریا Family Capilaria C. philipensis C. hepatica

Trichinella spiralis Female male

Trichinella spiralis Hosts: swine, rats, humans, bear, walrus, and other carnivores. Individual is the final Host for the adults and Intermediate host for Juvenile Geographic Distribution: Cosmopolitan. More common in temperate areas than tropics. There are at least seven sibling species and at least 3 strains Different hosts, ribosomal DNA, gene sequences, and allozymes Look identical

Trichinella spiralis Location: Adults in wall of small intestine. Juvenile in striated muscles and organs. Favorite are eye, tongue and masticatory muscles Then diaphragm and intercostal heavy muscles of arms and legs Why they prefer certain muscles is are unclear Transmission: Ingestion of Juvenile in under cooked meat.

Trichinella spiralis – Pathology and Symptoms Disease is trichinosis Trichiniasis or trichinelliasis The Great Mimic Mimics many other conditions Rarely exhibits a set of symptoms Symptoms depend on location, number and age of larval worms Most cases are asymptomatic Initial phase: flu-like symptom Caused by females penetrating mucosa As worms mature, symptoms may include nausea, vomiting, sweating and diarrhea for five to seven days. Body’s reaction to worm waste

Trichinella spiralis – symptoms and pathology Migration of larva causes many symptoms Including pneumonia, pleurisy, encephalitis, meningitis, nephritis, deafness, peritonitis, brain and eye damage, muscle stiffness, weak pulse, difficulty breathing, hallucinations Death is rare Usually due to inflammation of heart muscle, respiratory complications or kidney malfunction Trichinella spiralis – symptoms and pathology

Trichinella spiralis - Notes Largest intracellular parasite Juvenile invade a muscle cell and converts it into a nurse cell Alters the metabolism of the cell to do what it wants Alters gene expression so it doesn’t make contractile proteins Releases Vascular endothelial growth factor (VEGF) Stimulates formation of capillaries around cell Nurse cell secretes collagen coating Don’t understand how worm does it Eventually the body walls off the nurse cell by calcifying the walls Immune system will eventually kill the Juvenile But they can live over 39 years Trichinella spiralis - Notes

Trichinella spiralis - Notes Juvenile molt four times and become an adult in 30-32 hours from ingestion. Female gives birth to live Juvenile No egg stage Immunity has been demonstrated in mice Can be passed to young from immune mothers There are at least four variations of the life cycle which may be different species Domestic Use pigs and rats Sylvatic – Temperate zone Fox, bears Sylvatic – Torrid zone Hyenas, lions Sylvatic Frigid zone Polar bears, walrus

Life Cycle of T. spiralis Juvenile migrates to striated muscles Adults inside intestinal mucosa cell Female release Juvenile Enter muscle cell Life Cycle of T. spiralis Turns into nurse cell Four molts Penetrate intestinal mucosa Reach small intestine Infective in 4-8 weeks Juveniles swallowed

لارو تریشین در مقطع عضله

Diagnosis: Antigenic and serological tests, muscle biopsy plus case history. Treatment: No effective treatment. Thiabendazole has worked in experimental animals but results in human mixed Steroids reduce inflammation Bed rest and analgesics help relieve pain and discomfort Trichinella spiralis

تورم صورت در تریشینلازیس

Trichinella spiralis Prevention: Cook meat well. Most U.S. cases are from undercooked pork Includes processed meats, chops, sausages, ham, etc. Can also occur in bears, walrus, fox, etc. Rarely occurs in cattle and horses How they get it is unknown Can survive freezing down to –15oC

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