THE OCCURRENCE OF SETARIA IN REINDEER*
Setaria yehi Desset, 1966, is reported from domestic reindeer (Rangifer tarandus Linnaeus), maintained at College and Cantwell, Alaska. Microfilariae were present in blood from reindeer harboring S. yehi. Gross and microscopic findings in the infected animals revealed a low-grade peritonitis. Caribou, moose, dairy cows, goats, and dogs examined in the local areas were negative for microfilariae.
Epidemiology of the lymphatic-dwelling filarioid nematode Rumenfilaria andersoni in free-ranging moose (Alces alces) and other cervids of North America
BackgroundMoose (Alces alces) are a culturally and economically valued species in Minnesota, where the northeast population has decreased by 60 % since 2006. The cause of the decline is currently unclear; however, parasites, predation, and climate change have all been implicated. Nematode parasites are important pathogens in North American moose, potentially causing severe disease and mortality. Recent spread of Rumenfilaria andersoni, a filarioid nematode of moose, has been documented in Finnish cervids; however, little is known about the epidemiology of this parasite in North America.MethodsTo investigate the prevalence and distribution of R. andersoni, 584 blood samples were collected from live-captured and dead animals and screened microscopically for the presence of microfilariae using a modified Knott’s test. Microfilariae were identified based on morphological characteristics. A subset of Knott’s-positive animals was subjected to polymerase chain reaction (PCR) with filarioid-specific primers targeting the first internal transcribed spacer region (ITS-1) of the rRNA gene cluster.ResultsRumenfilaria microfilariae were present in 20.5 % of Minnesota moose (n = 352), with slight fluctuations observed over four years. Minnesota white-tailed deer (Odocoileus virginianus) (n = 2) and moose (n = 44) from Alaska, Montana, Washington, Maine, and New Hampshire also harbored R. andersoni, suggesting this parasite occurs widely throughout North American moose herds, and white-tailed deer can serve as a patent host. Sequence analysis of cervid blood (moose, n = 15; white-tailed deer, n = 1) confirmed the identity of R. andersoni and revealed the existence of two distinct clades. Genetic comparisons of R. andersoni isolates from North America and semi-domesticated Finnish reindeer found the two groups to be closely related, supporting previous hypotheses that R. andersoni was recently introduced into Finland by the importation of deer from the United States.ConclusionsTo the best of our knowledge these observations represent the first report of R. andersoni within the contiguous United States and reveal this nematode as a common parasite of North American moose and white-tailed deer. Although the implications of R. andersoni infection on moose health is unclear, increased awareness of this parasite will help prevent unintentional introduction of R. andersoni into naïve populations via the translocation of wild and captive cervids.
A Revision of the Nematode Genus Setaria Viborg, 1795, its Host-parasite Relationship, Speciation and Evolution
In a revision of the genus Setaria s.l. the author gives a review of the literature on the systematics of this group. The genus Setaria s.l. is divided into three genera. Hyraconema n.g. monotypic for H. loveridgei (Sandground, 1928), a primitive worm of the hyracoids; Setaria Viborg, 1795, monotypic for S. equina (Abildg., 1789) the common parasite of equine animals; and Artionema n.g. for the remaining species, all of which occur in artiodactyls. Artionema africana n.sp. is the genotype. A. africana is found in Tragelaphus spp. and cattle in various parts of continental Africa. The other new species A. hartwichi n.sp. is found in the European deer, Capreolus and Alces on continental Europe. The paper includes a discussion on host parasite relationship, phylogeny and the evolution of taxonomic characters in speciation. In the Subfamily Setariinae Yorke and Maplestone, 1926, the author recognizes five genera as follows: Skrjabinofilaria Trav., 1925; Hyraconema gen. nov., Setaria Viborg, 1795, Papillosetaria Vevers, 1923 and Artionema gen. nov. The paper ends with a host list.