Trichinellosis

What are the treatment options?  Trichinellosis can be diagnosed with a blood test or muscle biopsy. Anti-parasitic drugs and steroids are used to treat trichinellosis.  Nausea  Vomiting  Abdominal pain  Diarrhea Trichinellosis (trichinosis) is a foodborne illness caused by parasitic worms called Trichinella. People get this disease by eating undercooked or raw meat from an infected animal, most commonly bear and wild pigs. The disease can be very severe or even fatal, but it is easily prevented.

2. Clinical diagnosis during the muscle phase of disease-eyelid swelling, pain, and tenderness; swelling in muscles; small hemorrhages that resemble small splinters under the fingernails and the conjunctivitis of the eyes.
3. Also, a particular type of White Blood Cell (Eosinophils) are usually increased several times their normal concentration after the muscle phase starts (1).4. ELISA: useful method for detecting specific LgG antibodies.Enables early and specific serological diagnosis of Trichinellosis using excretory-secretory (ES) antigens obtained from the vitro cultures of T. spiralis.Looks for detection of lgG and lgM (6).
5. Latex Agglutination (LA): Quick way to determine the absence or presence of an antigen or antibody (7).
6. Biopsy of muscle that shows larvae in the muscle tissue (1).7. Bentonite Flocculation: Type of blood test, highly sensitive and nearly 100% specific.Becomes positive for Trichinella in about the third week.Antibodies ca be detected from blood samples but not until 3 to 5 weeks after infection (7).

General Characteristics:
When a human or animal ingests raw or undercooked flesh containing these cyst.Stomach acid and enzymes degrade the tough protective capsule during gastric digestion, releasing the larvae.The larvae then migrate to the epithelial mucosa of the small intestine, where they mature into adult worms.During stage of development they molt four times and mate.After mating, the female sheds the newborn larvae, which gets deposited into the blood or lymph vessels, and transported through circulatory system to capillaries of skeletal muscle cells.The larvae then escape the capillaries and penetrate the muscle fibers, where they proceed to encyst and form a nurse cell (3).

Historical Information:
In 1835, James Paget, 1st year medical student, first observed larval form of T. spiralis while witnessing an autopsy where muscle tissue with white flecks, "sandy diaphragm."Although Paget was the 1st to observe and record the findings, the parasite was named and published in a report by his professor, Richard Owen, who is now credited for the discovery of T. spiralis larval form.
The life cycle of T. spiralis was later discovered through a series of experiments conducted between 1850-1870 by German researchers Rudolph Virchow, Rudolph Leuckart, and Friedrich Albert von Zenker.Rudolph fed his dog a large quantity of infected human muscle tissue with white flecks.Days later, when he autopsied the now dead dog, he observed the adult worm in the small intestine.He concluded correctly that T. spiralis cases disease in humans as well (3).

Signs and Symptoms:
First symptoms of Trichinellosis occurs 12 hours to 2 days after consuming raw or undercooked meat include: Nausea, diarrhea, vomiting, fatigue, fever, and abdominal cramps.Five to seven days, facial edema.After ten days, intense muscular pain and difficulty breathing (1).
Symptoms while larvae are in the intestines include: Muscle aches and pains, high fever, swelling in eyes/face, sensitivity to light, eye infections, rashes, headaches, cough, and chills (4).

Microbial Virulence Mechanisms
Once a larvae occupies a muscle fiber cell in the muscle tissue, it forms an interesting complex called a nurse cell.The nurse cell is suspected to nourish and protect the larvae from host immune responses.Another interesting phenomena, is that the parasite has evolved a way of stimulating blood vessel development around the cell, in order to receive the nutrients it needs.The nurse cell-parasite complex can survive in the human host for up to 30 years and in most other species of mammal for the life span of the animal.While it is clear for this to occur, the worm must immuno-suppress the host, yet very little is known regarding the mechanism(s) employed by the parasite through which it keeps the host from killing it.( 5)

Treatment:
Ant-parasitic drugs can help prevent the progression of Trichinellosis by killing the adult worms to prevent further release of larvae.

Control / Prevention:
Proper food preparation.Avoid raw or undercooked pork, or other wild-animal meat.Cook meat to a temperature to ensure destruction of T. spiralis.Have wild meat irradiated.Irradiation will kill parasites in wild-animal meat and deep freezing for 3 weeks kills T. spiralis in some meats (5).

Current Cases/ Outbreaks:
During 2008-2012 a total of 90 cases of Trichinellosis were reported to CDC from 24 states.Six (7%) cases were excluded from analysis because case didn't meet the case definition.Total of 84 confirmed Trichinellosis cases, including five outbreaks that comprised 40 cases.Pork products were associated with 22 (26%) cases, including 10 (45%) commercial pork products, six (27%) that were linked with home-raised swine; five (23%) were unspecified.
During 2008-2012 five outbreaks were reported from four states (Alaska, California, Illinois, and Minnesota), involving 40 persons.
Fewer than 100 cases of trichinosis are reported in US annually; of those, more than 30% are associated with consuming wild game.Trichinosis occurs throughout the world except in Australia and in some pacific islands.The rate is high in Latin America and Asia, where there is no regulation of pig feed and little testing of meat.October 2008, outbreak of Trichinellosis occurred in northern California sickened 30 out of 38 attendees of an event at which meat from a black bear was served.Morphologic and molecular testing of muscle from leftover bear meat revealed that the bear was infected with Trichinella.Clinical records revealed a high attack rate for this outbreak!78% for persons consuming any bear meat and 100% for persons consuming raw or under-cooked bear meat (9).

Current Research on Other Means of Control/Prevention:
Gamma irradiation as a possible way of controlling the disease has occupied our attention in the past 18 months.The number of reported Trichinellosis cases has decreased since 1947.The decline in incidence of Trichinellosis is a result of decreased prevalence of Trichinella in commercial pork products.This is a consequence of government legislation and changes in U.S. pork industry including implementation of the 1980 Federal Swine Health Protection Act, which prohibited feeding potentially Trichinella-contaminated garbage to swine.
The decline in number of cases also might be attributed to USDA successfully educating consumers to fully cook fresh pork to temperatures high enough to inactivate Trichinella (8).