title: Investigation of and Response to 2 Plague Cases, Yosemite National Park, California, USA, 2015.
abstract: In August 2015, plague was diagnosed for 2 persons who had visited Yosemite National Park in California, USA. One case was septicemic and the other bubonic. Subsequent environmental investigation identified probable locations of exposure for each patient and evidence of epizootic plague in other areas of the park. Transmission of Yersinia pestis was detected by testing rodent serum, fleas, and rodent carcasses. The environmental investigation and whole-genome multilocus sequence typing of Y. pestis isolates from the patients and environmental samples indicated that the patients had been exposed in different locations and that at least 2 distinct strains of Y. pestis were circulating among vector-host populations in the area. Public education efforts and insecticide applications in select areas to control rodent fleas probably reduced the risk for plague transmission to park visitors and staff.
authors.forename: Mary
authors.initials: M
authors.lastname: Danforth
authors.forename: Mark
authors.initials: M
authors.lastname: Novak
authors.forename: Jeannine
authors.initials: J
authors.lastname: Petersen
authors.forename: Paul
authors.initials: P
authors.lastname: Mead
authors.forename: Luke
authors.initials: L
authors.lastname: Kingry
authors.forename: Matthew
authors.initials: M
authors.lastname: Weinburke
authors.forename: Danielle
authors.initials: D
authors.lastname: Buttke
authors.forename: Gregory
authors.initials: G
authors.lastname: Hacker
authors.forename: James
authors.initials: J
authors.lastname: Tucker
authors.forename: Michael
authors.initials: M
authors.lastname: Niemela
authors.forename: Bryan
authors.initials: B
authors.lastname: Jackson
authors.forename: Kerry
authors.initials: K
authors.lastname: Padgett
authors.forename: Kelly
authors.initials: K
authors.lastname: Liebman
authors.forename: Duc
authors.initials: D
authors.lastname: Vugia
authors.forename: Vicki
authors.initials: V
authors.lastname: Kramer
mesh_terms: D000483:Alleles; D000818:Animals; D002140:California / Q000453:epidemiology; D004199:Disease Vectors; D016680:Genome, Bacterial; D062306:Geography, Medical; D006801:Humans; D058885:Multilocus Sequence Typing; D009154:Mutation; D010930:Plague / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D016036:Seroepidemiologic Studies; D005423:Siphonaptera / Q000382:microbiology; D015010:Yersinia pestis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification
keywords: California; United States; Yersinia pestis; Yosemite; bacteria; bubonic plague; fleas; plague; rodents; septicemic plague; vector-borne infections