TRICHINELLA

SPIRALIS

JEEVAN KISHORE

GROUP:-20

Tbilisi state medical university

THE PARASITE'S TAXONOMY IS:  Class : Adenophorea Subclass : Enoplia Order : Stichosomida (Trichurata) Superfamily : Trichocephaloidea Family : Trichinellidae

Trichinella spiralis (green) is the most common member of the genus and is the primary cause of domestic animal

trichinosis.

INTRODUCTION…Trichinosis is caused by ingesting the larvae of

the nematode Trichinella in undercooked, infected tissue.

The roundworm is found in many different carnivorous animals and scavengers, and can

cause serious illness and even death in humans.

 Trichinella has a nearly worldwide distribitution, making it an incredibly successful parasite.

Important terms:Cyst: A protective wall that forms around the larva. 

Host : An organism that harbors a parasite providing food and shelter.

Reservoir: an animal host that maintains a parasite life cycle in the wild, and functions as a source of the parasite for humans.

Larva: The young and immature form of the worm.

Nematode: A type of roundworm with a long, unsegmented body.

Striated muscle: muscles of the skeletal system and of the heart.

Trichinella in Humans

An infected person can experience nausea, diarrhea, vomiting, fatigue,

fever, and abdominal discomfort in the first few days after infection from Contaminated meat.

The incubation period can last between 5 and 45 days, at which time headaches, fevers, chills, cough, eye swelling, aching joints, muscle pain, itchy skin, diarrhea

or constipation can set in. Splinter hemorrages of the fingernails, swelling and muscle pain are caused by larvae

moving through tissue.

WEAKNESS AND SORENESS MAY LAST MONTHS AFTER OTHER SYMPTOMS HAVE SUBSIDED. MANY PEOPLE

MAY NEVER BE DIAGNOSED SINCE MILD OR MODERATE TRICHINOSIS IS FREQUENTLY MISTAKEN FOR THE FLU OR ANOTHER COMMON ILLNESS. a HEAVILY INFECTED

PATIENT MAY HAVE PROBLEMS RELATED TO THE CENTRAL NERVOUS SYSTEM, IN ADDITION TO

POSSIBLE HEART AND RESPIRATORY PROBLEMS. VERY RARELY DO SEVERE CASES CAUSE DEATH.

swollen eyes[ periorbital edema] splinter hamorage

Reservoir Reservoir hosts include bears, pigs, rats, wild cats, foxes, dogs, wolves,

horses, seals and walruses. Domestic pigs are considered the dominant reservoir host, but there are many

different typical hosts throughout the world:

Temperate regions : pig, wild boar, horse, dog, bear, FoxTropical regions : wharthog, hyenaArctic regions : polar bear, walrus, wolf, fox 

TRANSMISSIONTransmission occurs by ingestion of infected tissue. Domestic pigs frequently become infected by

ingestion of uncooked garbage or infected rat carcasses. When

humans eat undercooked or raw meat from pigs and other reservoir hosts, they too become infected.

Trichinella has no vector.

L a r v a

Adult female Adult male

LIFE CYCLELarvae are ingested in raw or undercooked meat (i.e. pork) and develop into adults in the small intestine.adults are attached to or buried in the intestinal mucosa, where they mate. A female produces ~1,500 living young over a lifespan of 4 to 16 weeks

Larvae enter the lymphatic's and mesenteric veins, travel throughout the body, and eventually encyst in striated muscle. A cyst is a kind of protective wall, in this case created in reaction to the host's immune system. Larvae may remain viable for up to 25 years in humans!When viable cysts are ingested by a new host, the cycle begins again.

There are basically two pathogenic phases in the life cycle. Infection of the intestine is called the enteral phase and includes early larval stages in addition to immature and reproductive adult stages.

Larvae encysted in nurse cells in the parenteral phase.

DIAGNOSIS AND TREATMENT

Diagnosisperiorbital edema… fever… myositis…Eosinophilia …muscle biopsy…common blood test called the bentonite flocculation..ELISA test…

TreatmentEARLY TREATMENT

Mebendazole (Vermox) and thiabendazole (Mintezol) are

effective against intestinal larvae

SUPPORTIVE CAREAspirin and anti-inflammatory drugs are

effective, but corticosteroids may be necessary in more severe cases and

when myocarditis is involved.

PREVENTIONCook meat, especially pork, bear, walrus, and wild pig thoroughly .Freeze pork less than 6 inches thick for 20 days at 5 degrees F. Freezing is not very effective for the meat of arctic animals Cook all meat fed to pigs and

other animals and do not allow pigs to eat

carcasses of rats.Clean all tools used to prepare meat.You CANNOT rely on salting, drying, smoking or microwaving to kill the encysted worms.

THANK YOU