title: Rickettsial Infections among Ctenocephalides felis and Host Animals during a Flea-Borne Rickettsioses Outbreak in Orange County, California.
abstract: Due to a resurgence of flea-borne rickettsioses in Orange County, California, we investigated the etiologies of rickettsial infections of Ctenocephalides felis, the predominant fleas species obtained from opossums (Didelphis virginiana) and domestic cats (Felis catus), collected from case exposure sites and other areas in Orange County. In addition, we assessed the prevalence of IgG antibodies against spotted fever group (SFGR) and typhus group (TGR) rickettsiae in opossum sera. Of the 597 flea specimens collected from opossums and cats, 37.2% tested positive for Rickettsia. PCR and sequencing of rickettsial genes obtained from C. felis flea DNA preparations revealed the presence of R. typhi (1.3%), R. felis (28.0%) and R. felis-like organisms (7.5%). Sera from opossums contained TGR-specific (40.84%), but not SFGR-specific antibodies. The detection of R. felis and R. typhi in the C. felis fleas in Orange County highlights the potential risk for human infection with either of these pathogens, and underscores the need for further investigations incorporating specimens from humans, animal hosts, and invertebrate vectors in endemic areas. Such studies will be essential for establishing a link in the ongoing flea-borne rickettsioses outbreaks.
authors.affiliation: Naval Medical Research Center, Silver Spring, MD, United States of America.
authors.forename: Alice N
authors.identifier: http://orcid.org/0000-0002-0248-8463
authors.initials: AN
authors.lastname: Maina
authors.affiliation: Orange County Mosquito and Vector Control District, Garden Grove, CA, United States of America.
authors.forename: Carrie
authors.initials: C
authors.lastname: Fogarty
authors.affiliation: Orange County Mosquito and Vector Control District, Garden Grove, CA, United States of America.
authors.forename: Laura
authors.initials: L
authors.lastname: Krueger
authors.affiliation: Louisiana State University, Baton Rouge, LA, United States of America.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Macaluso
authors.affiliation: Naval Medical Research Center, Silver Spring, MD, United States of America.
authors.forename: Antony
authors.initials: A
authors.lastname: Odhiambo
authors.affiliation: Orange County Mosquito and Vector Control District, Garden Grove, CA, United States of America.
authors.forename: Kiet
authors.initials: K
authors.lastname: Nguyen
authors.affiliation: Naval Medical Research Center, Silver Spring, MD, United States of America.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Farris
authors.affiliation: Naval Medical Research Center, Silver Spring, MD, United States of America.|Shippensburg University, Shippensburg, PA, United States of America.
authors.forename: Alison
authors.initials: A
authors.lastname: Luce-Fedrow
authors.affiliation: Orange County Mosquito and Vector Control District, Garden Grove, CA, United States of America.
authors.forename: Stephen
authors.initials: S
authors.lastname: Bennett
authors.affiliation: Naval Medical Research Center, Silver Spring, MD, United States of America.
authors.forename: Ju
authors.initials: J
authors.lastname: Jiang
authors.affiliation: West Valley Mosquito and Vector Control District, Ontario, CA, United States of America.
authors.forename: Sokanary
authors.initials: S
authors.lastname: Sun
authors.affiliation: Orange County Mosquito and Vector Control District, Garden Grove, CA, United States of America.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Cummings
authors.affiliation: Naval Medical Research Center, Silver Spring, MD, United States of America.
authors.forename: Allen L
authors.initials: AL
authors.lastname: Richards
mesh_terms: D000818:Animals; D002140:California / Q000453:epidemiology; D002415:Cats / Q000097:blood / Q000382:microbiology / Q000469:parasitology*; D058251:Ctenocephalides / Q000382:microbiology*; D004196:Disease Outbreaks; D058267:Flea Infestations / Q000150:complications / Q000662:veterinary*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007303:Insect Vectors / Q000382:microbiology*; D009893:Opossums / Q000097:blood / Q000382:microbiology / Q000469:parasitology*; D012281:Rickettsia / Q000302:isolation & purification*; D012282:Rickettsia Infections / Q000097:blood / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*; D041161:Rickettsia felis / Q000302:isolation & purification; D012286:Rickettsia typhi / Q000302:isolation & purification
chemical_list: D007074:Immunoglobulin G