What is trichinellosis: trichinellosis is a world-wide zoonosis. Humans acquire the infection by consuming raw or improperly cooked infected meat from wild and synanthropic carnivores and omnivores (mammals, birds and reptiles) and pigs, horses, and other domestic animals infected with larve of nematode worms of the genus Trichinella. (Figure 1) All recognised species and genotypes can infect humans.

History of the International Trichinella Reference Centre (ITRC): the ITRC is the reference laboratory of both the International Commission on Trichinellosis (since 1988), the World Organization for Animal Health (since 1992) and of the European Union Reference Laboratory for Parasites (since 2006). The ITRC is the repository of Trichinella strains and source of materials and information for scientists, international and national institutions.

The ITRC today: to date, more than 7000 isolates of human and animal origin from throughout the world have been examined and identified at the species and/or genotype level. More than 40 isolates are maintained in vivo. These data have been vital to the establishment of a taxonomic system for Trichinella, which has had a great impact on the epidemiology and clinical management of these zoonotic parasites. ITRC users: more than 200 researchers from 52 countries have relied on the ITRC to identify isolates, to receive reference strains, antigens, DNA, reference sera from animals and humans and epidemiological information.

Trichinella systematics and distribution: two main clades are recognized in the genus Trichinella; one that encompasses nine taxa that encapsulate in host muscle tissue, and a second (including three species) that does not encapsulate following muscle cell differentiation. Trichinella nematodes show virtually a world-wide distribution in domestic and/or sylvatic animals, with the exception of Antarctica.
For more information read the following papers:

• Korhonen PK, Pozio E, La Rosa G, Chang BC, Koehler AV, Hoberg EP, Boag PR, Tan P, Jex AR, Hofmann A, Sternberg PW, Young ND, Gasser RB. 2016. Phylogenomic and biogeographic reconstruction of the Trichinella complex. Nat Commun. 7:10513.
• Pozio E. 2015. Trichinella spp. imported with live animals and meat. Vet Parasitol. 213:46-55.
• Pozio E. 2014. Searching for Trichinella: not all pigs are created equal. Trends Parasitol. 30:4-11.
• Pozio E, Zarlenga DS. 2013. New pieces of the Trichinella puzzle. Int J Parasitol. 43:983-97.
• Murrell KD, Pozio E. 2011. Worldwide occurrence and impact of human trichinellosis, 1986-2009. Emerg Infect Dis. 17:2194-202.
• Pozio E. 2007. World distribution of Trichinella spp. infections in animals and humans. Vet Parasitol. 149:3-21.
• Pozio E. 2005. The broad spectrum of Trichinella hosts: from cold- to warm-blooded animals. Vet Parasitol. 132:3-11.

Worldwide occurrence of Trichinella infections: consult the Epidemiological database to know if Trichinella infection occurs in humans and in domestic and wild animals of a country. The information is based on both old and recent reports published in scientific journals, books, congress abstracts, web sites, etc. The lack of information for a country (displayed as “no” in the database) does not mean that these zoonotic parasites are not present, but it means mostly the lack of information.