title: Relapsing fever group Borrelia in Southern California rodents.
abstract: Wild rodent reservoir host species were surveyed prospectively for infection with Borrelia hermsii, the causative agent of tick-borne relapsing fever in the western United States. Trapping occurred during the summer of 2009-2012 at field sites surrounding Big Bear Lake, CA, a region where human infection has been reported for many years. Using quantitative polymerase chain reaction (qPCR), we tested 207 rodents from 11 species and found chipmunks (Tamias spp.) and a woodrat (Neotoma macrotis) infected. Chipmunks represented the majority of captures at these sites. Sixteen of the 207 (7.7%; CI = 4.6-12.4) animals were qPCR-positive for Borrelia spp. associated with relapsing fever, and of those, we obtained bacterial DNA sequences from eight. The phylogram made from these sequences depict a clear association with B. hermsii genomic group I. In addition, we identified an infection with Borrelia coriaceae in a Tamias merriami, a potentially nonpathogenic member of the tick-borne relapsing fever group. Our findings support the hypothesis that chipmunk species play an important role in the maintenance of Borrelia species that cause tick-borne relapsing fever in the western United States, and therefore the risk of infection to people.
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Nieto
authors.forename: Mike B
authors.initials: MB
authors.lastname: Teglas
mesh_terms: D000818:Animals; D001898:Borrelia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D002140:California / Q000453:epidemiology; D010802:Phylogeny; D012061:Relapsing Fever / Q000453:epidemiology / Q000382:microbiology*; D012377:Rodentia; D015047:Zoonoses