Trichinosis is a parasitic disease caused by the type worm Trichinella . During initial infection, bowel invasion can cause diarrhea, abdominal pain, and vomiting. Migrating larvae to the muscle, which occurs about a week after infection, can lead to facial swelling, inflammation of the white eye, fever, muscle pain, and rash. Mild infections may be asymptomatic. Complications may include inflammation of the heart muscle, central nervous system involvement, and lung inflammation.
Trichinosis mainly spreads when cooked meat containing Trichinella cysts is eaten. Most often these are pork but can also occur from bears and dogs. Some subtypes of Trichinella can cause disease with T. spiralis to be the most common. Once eaten larvae are released from their cysts in the stomach. They then attack the small intestinal wall, where they develop into adult worms. After one week, the female releases new larvae that migrate to the voluntarily controlled muscle in which they form the cyst. Diagnosis is usually based on symptoms and confirmed by finding specific antibodies in blood or larvae in tissue biopsy.
The best way to prevent trichinosis is to cook meat completely. Food thermometers can verify that the temperature inside the meat is high enough. Infection is usually treated with antiparasitic drugs such as albendazole or mebendazole. Rapid treatment can kill adult worms and thus stop further worsening of symptoms. Both drugs are considered safe but have been associated with side effects such as bone marrow suppression. Its use during pregnancy or in children under 2 years of age is less studied but appears to be safe. Treatment with steroids is sometimes also required in severe cases. Without symptoms treatment usually heals within three months.
Worldwide about 10,000 infections occur a year. At least 55 countries including the United States, China, Argentina, and Russia have recently documented cases. Although this disease occurs in the tropics, it is rare there. The rate of trichinosis in the United States has decreased from about 400 cases per year in the 1940s to 20 per year in the 2000s. The risk of death from infection is low.
Video Trichinosis
Signs and symptoms
Most trichinosis infections have mild symptoms or no symptoms and no complications. There are two main phases for infection: enteral (intestinal) and parenteral (outside the intestine). Symptoms vary depending on the phase, species Trichinella , number of infested larvae, immunity age, sex, and host.
Enteral Phase
A large burden of adult worms in the intestine increases symptoms such as nausea, heartburn, dyspepsia, and diarrhea from two to seven days after infection, while small worm loads are generally asymptomatic. Eosinophilia appears earlier and increases rapidly.
Parenteral phase
The severity of symptoms caused by the migration of larvae from the gut depends on the number of larvae produced. When the larvae migrate through the tissues and blood vessels, the body's inflammatory response produces edema, muscle pain, fever, and weakness. The classic sign of trichinosis is periorbital edema, swelling around the eyes, which may be caused by vasculitis. Splinter hemorrhage in the nail is also a common symptom.
They may rarely cause enough damage to produce serious neurological deficits (such as ataxia or respiratory paralysis) of the worms entering the central nervous system. The CNS is compromised by trichinosis in 10-24% of cases reported from cerebral sinus vein thrombosis, a very rare form of stroke (3-4 cases per million annual incidents in adults). Trichinosis can be fatal depending on the severity of the infection; Death can occur 4-6 weeks after infection, and is usually caused by myocarditis, encephalitis, or pneumonia.
Maps Trichinosis
Cause
The classical agent is T. spiralis (found worldwide in many carnivorous and omnivorous animals, both domestic and sylvatic), but there are also seven species of sylvatic especially from Trichinella now known :
- Species and characteristics
- T. spiralis best adapted to pigs, most pathogenic to humans and cosmopolitan in distribution.
- T. britovi is the second most common species to infect humans; it is distributed throughout Europe, Asia, and northern and western Africa, usually in wild carnivores, wild pigs and pigs.
- T. murrelli also infects humans, especially from black bear meat; it is distributed among wild carnivores in North America.
- T. nativa , which has a high resistance to freezing, is found in the arctic and subarctic regions; hosted reservoirs including polar bears, arctic foxes, walruses and other wild games.
- T. nelsoni , found in Eastern African predators and carrion eaters, has been documented to cause some human cases.
- T. papuae infects mammals and reptiles, including crocodiles, humans, wild boars and domestic pigs; this species, found in Papua New Guinea and Thailand, is also not inhibited.
- T. pseudospiralis infects birds and mammals, and has shown infection in humans; it is an uncovered species.
- T. zimbabwensis can infect mammals, and possibly humans; this unencapsulated species was detected in crocodiles in Africa.
Taxonomy
- Kingdom: Animalia
- Phylum: Nematodes
- Class: Adenophorea
- Orders: Trichurida
- Family: Trichinellidae
- Genus: Trichinella
Life cycle
The typical life cycle for T. spiralis involves humans, pigs, and rodents. A pig becomes infected when eating infectious cysts in raw meat, often pork or mouse pig (sylvatic cycle). A human being becomes infected by consuming an infected or undercooked pig (domestic cycle). In the abdomen, cysts from infected half-baked meat are followed by pepsin and hydrochloric acid, which help release the larvae from the cyst into the stomach. The larvae then migrate to the small intestine, and dig into the intestinal mucosa, where they molt four times before becoming an adult.
Thirty to 34 hours after the cyst is initially digested, the adult couple, and within five days produce the larvae. Adult worms can only reproduce for a limited time, because the immune system will eventually expel them from the small intestine. Larvae then use their piercing mouth, called "stylet", to pass through the intestinal mucosa and enter the lymphatic vessels, and then enter the bloodstream.
Larvae travel by capillaries to various organs, such as the retina, myocardium, or lymph nodes; However, only the larvae migrate to skeletal muscle cells survive and encyst. Cells host larvae into nurse cells, where the larvae will be packaged, potentially for host life, waiting for the host to eat. Development of capillary tissue around the nurse's cells completes the encystation of the larvae. Trichinosis is not transmitted through the soil, because the parasites do not lay eggs, nor can they last long beyond the host.
Diagnosis
The diagnosis of trichinosis is confirmed by a combination of history of exposure, clinical diagnosis, and laboratory testing.
Exposure history
Epidemiological investigations can be performed to determine the patient's exposure to infected meat. Often, infections arise from the preparation of contaminated meat homes, in which case a meat microscope can be used to determine the infection. Determination of exposure does not have to be directly from laboratory-confirmed infected animals. Indirect exposure criteria include the consumption of confirmed laboratory confirmed animal products, or shared public exposure with confirmed laboratory confirmed laboratories.
Clinical diagnosis
Clinical presentation of generalized trichinosis symptoms may also indicate infection. These symptoms include swollen eyes, bleeding splinters, nonspecific gastroenteritis, and muscle aches. The case definition for trichinosis at the European Center for Disease Control states "at least three of the following six: fever, muscle aches and pains, gastrointestinal symptoms, facial edema, eosinophilia, and subconjuctival, subungual, and retinal hemorrhages."
Laboratory testing
Blood tests and microscopy can be used to help diagnose trichinosis. Blood tests include complete blood counts for eosinophilia, creatine phosphokinase activity, and various immunoassays such as ELISA for larval antigens.
Prevention
Legislation
Laws and rules for food producers can improve food safety for consumers, such as the rules set by the European Commission for inspection, rodent control, and hygiene improvement. Similar protocols exist in the United States, in the USDA guidelines for agriculture and the responsibility of slaughtering animals in inspecting pork.
Education and training
Public education about the dangers of consuming raw and undercooked meat, especially pork, can reduce the rate of infection. Hunters are also a risky population due to contact and wild game consumption, including bears. Thus, many countries, such as New York, require completion of courses in such matters before hunting licenses can be obtained.
Food preparation
Larvae can be killed by heating or irradiating raw meat. Freezing is usually only effective for T. spiralis , because other species, such as T. nativa , are freezing and can survive in long-term freezing.
- All meat (including pork) can be prepared safely by cooking to an internal temperature of 165Ã, Â ° F (74Ã, Â ° C) or higher for 15 seconds or more.
- Wild game: Wild game meat must be thoroughly cooked (see meat preparation above) Wild game freezing does not kill all larvae of trichinosis larvae. This is because the worm species that normally attack wild game can withstand freezing.
- Pork: Pork frozen pieces less than 6Ã, inch thick for 20 days at 5 ° F (-15 ° C) or three days at -4 ° F (-20 ° C) kill T. spiralis worm larvae; but this will not kill other trichinotic larvae worm species, such as T. nativa , if they have fulfilled the supply of pork (which is not possible, because of geography).
Pork can be cooked safely to a slightly lower temperature, provided that the internal meat temperature is at least as hot as at least as listed in the USDA table below. Nonetheless, it is wise to allow the margin of error to internal temperature variations in certain pieces of pork, which may have bones that affect temperature uniformity. In addition, kitchen thermometers have measurement errors that should be considered. Pork can be cooked significantly longer and at a higher uniform internal temperature than the ones listed below for safe.
Unsafe and unreliable meat cooking methods include the use of microwave ovens, drying, drying, and smoking, as these methods are difficult to standardize and control.
Pig farm
- Keeping pigs with clean pens, with washable floors (like concrete)
- Not allowing pigs to eat other animal carcasses, including mice, which may be infected by Trichinella
- Clean the meat grinder thoroughly while preparing ground meat
- Control and destruction of meat containing trichinae, for example, proper disposal and disposal of pig diaphragms prior to the sale of general flesh
The Centers for Disease Control and Prevention make the following recommendations: "Curing (smoking), drying, smoking, or cooking meat by microwaves does not consistently kill infective worms." However, under the conditions of controlled commercial food processing, some of these methods are considered effective by the United States Department of Agriculture (USDA).
USDA's Animal and Plant Health Inspection Service (APHIS) is responsible for regulations on imports of pigs from foreign countries. Foreign Origin Meat and Meat Products, Pork Parts include pork (cooked, dried and dried, and fresh). APHIS developed the National Trichinae Certification Program; this is a voluntary "pre-harvest" program for US pig producers "which will provide pig management practice documentation" to reduce the incidence of Trichinella on pigs. The CDC reports 0.013% of US pigs are infected with Trichinella .
Treatment
As desired with most diseases, early treatment is better and reduces the risk of disease. If larvae do encyst in skeletal muscle cells, they can remain infectious for months to years.
Primary care
Early anthelmintic administration, such as mebendazole or albendazol, reduces the likelihood of dilution of the larvae, especially if given within three days after infection. However, most cases are diagnosed after this time.
In humans, Mebendazole (200-400 mg three times daily for three days) or albendazole (400 mg twice daily for 8-14 days) is given to treat trichinosis. These drugs prevent newly hatched larvae from developing, but should not be given to pregnant women or children under the age of two.
Secondary care
After infection, steroids, such as prednisone can be used to relieve muscle pain associated with larval migration.
Vaccine research
Researchers trying to develop a vaccine for Trichinella have tried to use "larvae extract, secretory secretory antigen, DNA, or recombinant antigen protein." Currently there is no marketable vaccine for trichinosis, but experimental mouse research suggests a possibility. In one study, microwave larvae Trichinella were used to immunize mice, which were then infected. Depending on the dose and frequency of immunization, the results range from decreasing number of larvae to complete protection from trichinosis.
Another study, Dea-Ayuela et al. (2006) used extracts and excretory secretory products from the first-stage larvae to produce oral vaccines. To prevent gastric acid from dissolving antigen before it reaches the small intestine, scientists encapsulate antigen in microcapsules. This vaccine significantly increases CD4 cell levels, and increases serum IgGq and IgA-specific antigens, resulting in a statistically significant decrease in the average number of adult worms in the rat's small intestine. The importance of this approach is that, if white blood cells in the small intestine have been exposed to Trichinella antigen (through vaccination), when an individual is infected, the immune system will respond to expel worms from the small intestum quickly enough to preventing female worms from releasing their larvae. Yuan Gu et al. (2008) tested DNA vaccine in mice that "induced a 25% reduction in muscle larval load in BALB/c rats in response to T. spiralis infection".
Epidemiology
About 11 million people are infected with Trichinella ; Trichinella spiralis is the species responsible for most of these infections. Infection was once very common, but the disease is now rare in developed countries. However, there are two known outbreaks by 2015. In the first outbreak, about 40 people were infected in Liguria, Italy, during New Year's Eve celebrations. A second outbreak occurred in France, linked to pork sausage from Corsica, which was eaten raw. The incidence of trichinosis in the US has declined dramatically in the last century. From 1997 to 2001, an annual average of 12 cases per year was reported in the United States. The number of cases declined because the law prohibits feeding raw meat to pigs, an increase in freezing of commercial pigs and homes, and public awareness of the dangers of consuming raw or undercooked meat products.
China reports about 10,000 cases each year, and therefore the country with the highest number of cases. In China, between 1964 and 1998, more than 20,000 people were infected with Trichinosis, and more than 200 people died.
In developing countries, most infections are associated with undercooked pigs. For example, in Thailand, between 200 and 600 cases are reported each year around the Thai New Year. This is largely due to a particular delicacy, larb , which calls for half-cooked pork as part of the recipe. In some parts of Eastern Europe, the World Health Organization (WHO) reports, some swine herds have a trichinosis infection rate above 50%, and there is a large number of human infections. United States
Historically, pork products are considered most at risk of infecting humans with Trichinella spiralis. However, surveillance of trichinosis performed between 1997-2001 showed a higher percentage of cases caused by wild game consumption (sylvatic transmission cycle). This is presumably due to the Federal Swine Health Protection Act (Public Law 96-468) passed by Congress in 1980. Prior to this action, pigs were fed trash potentially infected by Trichinella spiralis. This action is put in place to prevent trichinella contaminated food from being given to pigs. In addition, other requirements apply, such as rodent control, limiting commercial pig contacts with wildlife, maintaining good hygiene, and removing dead pigs from cages immediately.
Between 2002 and 2007, 11 cases of trichinosis were reported to the CDC each year on average in the United States; this is mostly the result of consuming less mature games, (sylvatic transmission) or home pig (domestic transmission). Trichinosis is common in developing countries, where meat is fed to raw or undercooked pigs, but infections also appear in developed countries in Europe and North America, where pork or raw or semi-cooked wild game can be consumed as a delicacy.
Religious group
Kashrut and kosher diet laws of Judaism and Islam forbid eating pork. In the 19th century, when the relationship between trichinosis and half-baked pigs was first established, it was suggested that this association was the reason for the ban, reminiscent of the previous opinion of the medieval Jewish philosopher Maimonides that food prohibited by Jewish law was "unhealthy." "This theory is controversial, and ultimately no longer favorable.
Reemergence
The loss of pathogens from domestic pigs has led to relaxation of legislation and control efforts by the veterinary public health system. Trichinosis has recently been regarded as an emerging zoonosis, coupled with increased distribution of meat products, political change, climate change, and increased sylvatic transmission.
Major socio-political changes may produce conditions that favor the awakening of Trichinella infection in pigs and, consequently, in humans. For example, "the overthrow of social and political structures in the 1990s" in Romania led to an increase in the incidence rate of trichinosis.
History
In early 1835, trichinosis was known to be caused by parasites, but the mechanism of infection was not clear at the time. A decade later, the American scientist Joseph Leidy pointed to the undercooked meat as the main vector for the parasite, and it was not until two decades later that this hypothesis was fully accepted by the scientific community.
Parasite
The circumstances surrounding the first observation and identification of the controversial Trichinella spiralis are due to the lack of records. In 1835, James Paget, a first-year medical student, first observed the form of T. spiralis larvae while watching an autopsy at St. Hospital. Bartholomew in London. Paget took a special interest in the presentation of muscles with white spots, described as "sandy diaphragms".
Although Paget is most likely the first person to have noticed and recorded these findings, the parasite was named and published in a report by his professor, Richard Owen, who is now credited for the discovery of the larval T. spiralis.
Life cycle
A series of experiments conducted between 1850 and 1870 by German researchers Rudolf Virchow, Rudolf Leuckart and Friedrich Albert von Zenker, which involved feeding infected meat to dogs and subsequent necropsies, led to the discovery of the Trichinella cycle of life. Through this experiment, Virchow was able to illustrate the development and infectivity of the T. spiralis .
Research
The International Commission on Trichinellosis (ICT) was established in Budapest in 1958. Its mission is to exchange information on epidemiology, biology, pathophysiology, immunology, and clinical aspects of trichinosis in humans and animals. Prevention is the ultimate goal. Since the creation of ICT, its members (more than 110 out of 46 countries) have regularly assembled and worked together during meetings held every four years: the International Conference on Trichinellosis.
See also
- List of parasites (human)
- Nurse cell
- Trichinella spiralis
References
External links
- Komisi Internasional tentang halaman web trichinellosis
- CDC Departemen Penyakit Parasit - Trichinosis
- Jokelainen P, NÃÆ'¤reaho A, HÃÆ'¤lli O, Heinonen M, Sukura A (Juni 2012). "Babi hutan bertani yang terkena Toxoplasma gondii dan Trichinella spp". Dokter hewan. Parasitol . 187 : 323-7. doi: 10.1016/j.vetpar.2011.12.026. PMID 22244535.
Source of the article : Wikipedia
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