A Cluster of Pediatric Endemic Typhus Cases in Orange County, California

Abstract

Murine typhus is typically a mild febrile illness caused by Rickettsia typhi, generally confined to Texas and Southern California. Clinicians should consider early treatment with doxycycline when presented with a child having protracted fever, rash, and headache.We present 5 pediatric cases and a literature review highlighting the changing epidemiology and diagnostic difficulty of typhus.

Two Pathogens and One Disease: Detection and Identification of Flea-Borne Rickettsiae in Areas Endemic for Murine Typhus in California

“…Humans become infected with R. typhi through accidental contact with infected fleas and their feces by inhalation or scarification into damaged skin (Azad 1990). While the number of cases reported in the United States has decreased from a peak of several thousand cases per year during the early 1940s to <100 cases per year currently (Civen and Ngo 2008), murine typhus is still an endemic disease and a public health concern in Hawaii, the gulf coast of Texas, and southern California (Fergie et al 2000;Centers for Disease Control andPrevention 2003, 2009;Purcell et al 2007;Civen and Ngo 2008;Green et al 2011).…”

“…However, to the best of our knowledge, no confirmed human infections because of R. felis have been reported in California. Only murine typhus is currently diagnosed using serological methods with R. typhi antigen and reported in California (Green et al 2011), despite the significant presence and wide distribution of R. felis in both urban and suburban environments (Civen andNgo 2008, Abramowicz et al 2011). Sera from humans infected with R. felis contain antibody reacting with R. typhi antigen detectable by both microimmunofluorescence assay and western blotting assay; similarly, sera from patients with confirmed diagnosis of murine typhus cross-react with R. felis antigen (Znasen et al 2006, Wiggers et al 2005, Pérez-Arellano et al 2005, Raoult et al 2001.…”

Acute Febrile Illness and Complications Due to Murine Typhus, Texas, USA1,2

“…Murine typhus causes a syndrome characterized by nonspecific manifestations, including fever, headache, myalgias, malaise, nausea, and vomiting in more than half of cases. This syndrome has previously been described throughout the world, including the southwestern United States ( 1 , 4 , 5 , 11 – 13 ) and California ( 2 , 14 ), as well as Europe ( 3 , 15 – 17 ).…”

Rickettsial Infections among Cats and Cat Fleas in Riverside County, California

“…Several flea-borne rickettsiosis outbreaks in Los Angeles and Orange counties have been very focal geographically, occurring in case clusters in families or mobile home communities with high cat densities. 54,55 Although exposure to flea-borne rickettsial disease agents is recognized as being highly variable and ecologically complex, 12 further research in the eco-epidemiology of flea-borne rickettsiosis is needed to provide a better understanding of the causes of these outbreaks.…”