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

2. 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

3. Trichinella spiralis
Female
male

5. 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

6. 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.

7. 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

8. 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

9. 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

10. Trichinella spiralis - Notes
Juvenile molt four times and become an adult in 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

11. 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

13. لارو تریشین در مقطع عضله

17. 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

19. تورم صورت در تریشینلازیس

21. 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

22. کنترل و پیشگیری : سوزاندن لاشه خوک های الوده به تریشین