title: Sylvatic Trichinella spp. infection in Finland.
abstract: Although human infections caused by Trichinella sp. have not been reported in Finland for several decades and Trichinella sp. infection in pork has become virtually extinct in the last decade, sylvatic Trichinella spp. infection is still highly prevalent in Finland. Muscle digestion of 2,483 carnivorous wild animals from 9 host species during 1999-2005 showed 617 positive animals (24.8%). Molecular identification from 328 larval isolates revealed 4 different endemic Trichinella species, i.e., T. nativa, T. spiralis, T. britovi, and T. pseudospiralis. Seven percent of the infected animals carried mixed infections. Trichinella nativa was the most common species (74%), but T. spiralis was identified in 12%, T. britovi in 6%, and T. pseudospiralis in 1% of the animals. Host species showed different sample prevalence and Trichinella species distribution. Geographical distribution also varied, with the southern part of the country having significantly higher percentages than the northern part. Infection density was dependent on both the infecting Trichinella species and the host species. Trichinella spiralis was discovered in areas with no known domestic infection cases, indicating that it can also occur in the sylvatic cycle. Raccoon dogs and red foxes are the most important reservoir animals for T. spiralis , as well as for the sylvatic Trichinella species in Finland.
authors.affiliation: Department of Basic Veterinary Sciences (FINPAR), Faculty of Veterinary Medicine, P.O. Box 66, FI-00014 University of Helsinki, Finland. niina.airas@helsinki.fi
authors.forename: Niina
authors.initials: N
authors.lastname: Airas
authors.forename: Seppo
authors.initials: S
authors.lastname: Saari
authors.forename: Taina
authors.initials: T
authors.lastname: Mikkonen
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Virtala
authors.forename: Jani
authors.initials: J
authors.lastname: Pellikka
authors.forename: Antti
authors.initials: A
authors.lastname: Oksanen
authors.forename: Marja
authors.initials: M
authors.lastname: Isomursu
authors.forename: Seija-Sisko
authors.initials: SS
authors.lastname: Kilpelä
authors.forename: Chae W
authors.initials: CW
authors.lastname: Lim
authors.forename: Antti
authors.initials: A
authors.lastname: Sukura
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000835:Animals, Wild / Q000469:parasitology*; D002335:Carnivora / Q000469:parasitology*; D003430:Cross-Sectional Studies; D004197:Disease Reservoirs / Q000469:parasitology; D005387:Finland / Q000453:epidemiology; D005589:Foxes / Q000469:parasitology; D006790:Host-Parasite Interactions; D016014:Linear Models; D016015:Logistic Models; D046008:Lynx / Q000469:parasitology; D018482:Muscle, Skeletal / Q000469:parasitology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D046031:Raccoon Dogs / Q000469:parasitology; D013045:Species Specificity; D018709:Statistics, Nonparametric; D014234:Trichinella / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014235:Trichinellosis / Q000453:epidemiology / Q000662:veterinary*; D001503:Ursidae / Q000469:parasitology; D019596:Wolves / Q000469:parasitology