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Background: The zoonotic nematode Trichinella britovi was discovered in two neighboring Mediterranean islands of Corsica and Sardinia, almost simultaneously at the beginning of the 21st century. An epidemiological link between the two parasite populations was generally assumed. In 2015, an outbreak of trichinellosis in Nice, the South of France, was reportedly caused by the consumption of raw pork delicatessen imported from Corsica. The aims of the present study were to investigate, by multilocus genotype (MLG) analyses, the hypothesis of the common origin of the Corsican and Sardinian T. britovi foci and to trace "from fork to farm" the origin of the pork product, which caused a trichinellosis outbreak in mainland France in 2015. Methods: Sixty-three T. britovi isolates were collected from animals and pork products of Sardinia and Corsica islands and from mainland of Italy, France and Spain. We analyzed genetic variability at four polymorphic microsatellite loci by two independent algorithms, the Bayesian and multivariate analyses, to evaluate the genetic relationships of 1367 single larvae. Results: Trichinella britovi isolates of the two islands showed different genetic structures and the Bayesian analysis revealed a different membership of the two insular populations. Furthermore, two geographically separate genetic groups were identified among Corsican isolates. Lastly, the origin of the pork delicatessen marketed in Nice was linked to a breeder-butcher in Corsica. Conclusions: The low level of genetic admixture of the insular T. britovi isolates suggests that this pathogen colonized the two islands by separate events. On the other hand in Corsica, although the isolates share the same genetic structure, geographically separate isolates showed different membership. We suggest the MLG analysis as a suitable method in supporting epidemiological investigations to trace "from fork to farm" insular populations of T. britovi. [ABSTRACT FROM AUTHOR]

Abstract: For 60 years, the islands of the Mediterranean basin were considered to be Trichinella-free. In April 2005, an outbreak of human trichinellosis due to the consumption of infected pork involved 11 persons in the villages of Orgosolo and Lanusei (Nuoro province) on the island of Sardinia (Italy). We conducted an investigation to identify free-range and backyard pigs and other humans with Trichinella infection in the area of the 2005 outbreak. We also tested wild animals from various parts of Sardinia. In December 2005, eight persons were found to have been infected, and in May 2007 there was a single case of infection. The sources of all infections were domestic pigs. Artificial digestion of muscle samples from 681 pigs (325 free-range and 356 backyard pigs) revealed Trichinella sp. larvae in four sows (1.2%). All larvae, including those from the consumed pork products, were identified as Trichinella britovi. All infected pigs originated from the Orgosolo municipality. None of the 6188 wild boars (Sus scrofa) or 13 red foxes (Vulpes vulpes) examined were positive for Trichinella sp., suggesting that this parasite is restricted to free-range pigs. The origin of infected animals on Sardinia remains to be determined, although it could be related to the presence of T. britovi-infected animals on the island of Corsica (France). [Copyright &y& Elsevier]

The zoonotic nematode Trichinella britovi has been documented in animals and/or humans of the Mediterranean islands of Corsica and Sardinia since 2004. From 2005 to 2007 in the Sardinia island, several surveys had shown that T. britovi was circulating among backyard and free-ranging pigs reared in the Orgosolo municipality but all attempts had failed to detect this parasite in wild susceptible animals. The aim of the present work was to investigate the circulation of T. britovi in pigs and wildlife of the Orgosolo municipality, and of surrounding municipalities and provinces in the 2010–2014 slaughtering/hunting seasons. The results show that the T. britovi circulation was still restricted to the Orgosolo municipality with a prevalence of 2.6% in free-ranging pigs and 0.2% in backyard pigs but, for the first time, this parasite was detected also in 0.4% of wild boar, and 27.6% of red foxes. No infection was detected in backyard pigs, wild boar, and red foxes of the other municipalities and provinces. Since 1978, African swine fever is endemic in Sardinia and foci of this virus are still active in the investigated areas favoring cannibalism and, consequently, the T. britovi transmission, due to the high mortality rate caused by this virus. This is the first documented report on the transmission of T. britovi between the domestic and the sylvatic cycle. The health authority of the island must provide a service to dispose animal carcasses and offal, stamping out illegal free-ranging pigs, and train hunters and pig owners to manage waste and by-products according to the EU regulations. [ABSTRACT FROM AUTHOR]

Abstract: Trichinella sp. infection has been documented in both humans and animals in most Mediterranean countries, yet in the past 60 years no infections have been reported on the Mediterranean islands. We describe the first outbreak of Trichinella sp. infection to have been reported on the island of Sardinia. The outbreak occurred in two villages in 2005 and involved 11 persons who had eaten raw sausages made from the same free-ranging sow. All 11 persons developed signs and symptoms of trichinellosis and seroconverted within 48 days of consuming the infected meat. The etiological agent was Trichinella britovi. Sardinia, like all Mediterranean islands, had been considered to be Trichinella-free. The present report, together with a recent report of T. britovi infection in animals on the nearby island of Corsica (France), raises questions as to the validity of the concept of Trichinella-free areas or regions. [Copyright &y& Elsevier]