a voluntary "preharvest" program for u.s. swine producers "that will provide documentation of swine management practices" to reduce the incidence of trichinella in swine. the cdc reports 0.013% of u.s. swine are infected with trichinella. treatment as with most diseases, early treatment is better and decreases the risk of developing disease. if larvae do encyst in skeletal muscle cells, they can remain infectious for months to years. primary treatment early administration of anthelmintics, such as mebendazole or albendazole, decreases the likelihood of larval encystation, particularly if given within three days of infection. however, most cases are diagnosed after this time. in humans, mebendazole (200–400 mg three times a day for three days) or albendazole (400 mg twice a day 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 two years of age. medical references from the 1940s described no specific treatment for trichinosis at the time, but intravenous injection of calcium salts was found to be useful in managing symptoms related to severe toxemia from the infection. secondary treatment after infection, steroids, such as prednisone, may be used to relieve muscle pain associated with larval migration. vaccine research researchers trying to develop a vaccine for trichinella have tried using either "larval extracts, excretory–secretory antigen, dna, or recombinant antigen protein." currently, no marketable vaccine is available for trichinosis, but experimental mouse studies have suggested possibilities. in one study, microwaved trichinella larvae were used to immunize mice (orally or intraperitoneally), which were subsequently infected. depending on the dosage and frequency of immunization, results ranged from a decreased larval count to complete protection from trichinosis. another study used extracts and excretory–secretory products from first-stage larvae to produce an oral vaccine. to prevent gastric acids from dissolving the antigens before reaching the small intestine, scientists encapsulated the antigens in microcapsules. this vaccine significantly increased cd4+ cell levels, and increased antigen-specific serum iggq and iga, resulting in a statistically significant reduction in the average number of adult worms in the small intestines of mice. the significance of this approach is that, if the white blood cells in the small intestine have been exposed to trichinella antigens (through vaccination), when an individual does get infected, the immune system will respond to expel the worms from the small intestine fast enough to prevent the female worms from releasing their larvae. a dna vaccine tested on mice "induced a muscle larva burden reduction in balb/c mice by 29% in response to t. spiralis infection". epidemiology pork sausages eaten raw by consumers caused an outbreak of trichinellosis in 2015 in france. about 11 million humans are infected with trichinella; t. spiralis is the species responsible for most of these infections. infection was once very common, but this disease is now rare in the developed world, but two known outbreaks occurred in 2015. in the first outbreak, around 40 people were infected in liguria, italy, during a new year's eve celebration. the second outbreak in france was associated with pork sausages from corsica, which were eaten raw, affecting 14 people in total. the incidence of trichinosis in the u.s. has decreased dramatically in the past century from an average of 400 cases per year mid-20th century down to an annual average of 20 cases per year (2008–10). the number of cases has decreased because of legislation prohibiting the feeding of raw meat garbage to hogs, increased commercial and home freezing of pork, and the public awareness of the danger of eating raw or undercooked pork products. china reports around 10,000 cases every year, so is the country with the highest number of cases. in china, between 1964 and 1998, over 20,000 people became infected with trichinosis, and more than 200 people died. trichinosis is common in developing countries where meat fed to pigs is raw or undercooked, but infections also arise in developed countries in europe where raw or undercooked pork, wild boar and horse meat may be consumed as delicacies. in the developing world, most infections are associated with undercooked pork. for example, in thailand, between 200 and 600 cases are reported annually around the thai new year. this is mostly attributable to a particular delicacy, larb, which calls for undercooked pork as part of the recipe. in parts of eastern europe, the world health organization reports, some swine herds have trichinosis infection rates above 50%, with correspondingly large numbers of human infections. united states historically, pork products were thought to have the most risk of infecting humans with t. spiralis. however, a trichinosis surveillance conducted between 1997 and 2001 showed a higher percentage of cases caused by consumption of wild game (the sylvatic transmission cycle). this is thought to be due to the federal swine health protection act (public law 96-468) that was passed by congress in 1980. prior to this act, swine were fed garbage that could potentially be infected by t. spiralis. this act was put in place to prevent trichinella-contaminated food from being given to swine. additionally, other requirements were put in place, such as rodent control, limiting commercial swine contact with wildlife, maintaining good hygiene, and removing dead pigs from pens immediately. between 2002 and 2007, 11 trichinosis cases were reported to the cdc each year on average in the united states, and 2008–10 averaged 20 cases per year; these were mostly the result of consuming undercooked game (sylvatic transmission) or home-reared pigs (domestic transmission). religious groups the kashrut and halal dietary laws of judaism and islam prohibit eating pork. in the 19th century, when the association between trichinosis and undercooked pork was first established, this association was suggested to be the reason for the prohibition, reminiscent of the earlier opinion of medieval jewish philosopher maimonides that food forbidden by jewish law was "unwholesome". this theory was controversial, and eventually fell out of favor. reemergence the disappearance of the pathogen from domestic pigs has led to a relaxation of legislation and control efforts by veterinary public health systems. trichinosis has lately been thought of as a re-emerging zoonosis, supplemented by the increased distribution of meat products, political changes, a changing climate, and increasing sylvatic transmission. major sociopolitical changes can produce conditions that favor the resurgence of trichinella infections in swine and, consequently, in humans. for instance, "the overthrow of the social and political structures in the 1990s" in romania led to an increase in the incidence rate of trichinosis. history as early as 1835, trichinosis was known to have been caused by a parasite, but the mechanism of infection was unclear at the time. a decade later, american scientist joseph leidy pinpointed undercooked meat as the primary vector for the parasite, and two decades afterwards, this hypothesis was fully accepted by the scientific community. parasite the circumstances surrounding the first observation and identification of t. spiralis are controversial, due to a lack of records. in 1835, james paget, a first-year medical student, first observed the larval form of t. spiralis, while witnessing an autopsy at st. bartholomew’s hospital in london. paget took special interest in the presentation of muscle with white flecks, described as a "sandy diaphragm". 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 t. spiralis larval form. lifecycle a series of experiments conducted between 1850 and 1870 by the german researchers rudolf virchow, rudolf leuckart, and friedrich albert von zenker, which involved feeding infected meat to a dog and performing the subsequent necropsy, led to the discovery of the lifecycle of trichinella. through these experiments, virchow was able to describe the development and infectivity of t. spiralis. research the international commission on trichinellosis (ict) was formed in budapest in 1958. its mission is to exchange information on the epidemiology, biology, pathophysiology, immunology, and clinical aspects of trichinosis in humans and animals. prevention is a primary goal. since the creation of the ict, its members (more than 110 from 46 countries) have regularly gathered and worked together during meetings held every four years: the international conference on trichinellosis.