Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Apr 20;12(4):e0006385.
doi: 10.1371/journal.pntd.0006385. eCollection 2018 Apr.

A 2015 outbreak of flea-borne rickettsiosis in San Gabriel Valley, Los Angeles County, California

Kimberly Nelson  1 , Alice N Maina  2 , Angela Brisco  1 , Chelsea Foo  3   4 , Curtis Croker  3 , Van Ngo  3 , Rachel Civen  3   5 , Allen L Richards  2 , Kenn Fujioka  1 , J Wakoli Wekesa  1
Affiliations

A 2015 outbreak of flea-borne rickettsiosis in San Gabriel Valley, Los Angeles County, California

Kimberly Nelson et al. PLoS Negl Trop Dis. .

Abstract

Although flea-borne rickettsiosis is endemic in Los Angeles County, outbreaks are rare. In the spring of 2015 three human cases of flea-borne rickettsiosis among residents of a mobile home community (MHC) prompted an investigation. Fleas were ubiquitous in common areas due to presence of flea-infested opossums and overabundant outdoor cats and dogs. The MHC was summarily abated in June 2015, and within five months, flea control and removal of animals significantly reduced the flea population. Two additional epidemiologically-linked human cases of flea-borne rickettsiosis detected at the MHC were suspected to have occurred before control efforts began. Molecular testing of 106 individual and 85 pooled cat fleas, blood and ear tissue samples from three opossums and thirteen feral cats using PCR amplification and DNA sequencing detected rickettsial DNA in 18.8% of the fleas. Seventeen percent of these cat fleas tested positive for R. felis-specific DNA compared to under two (<2) percent for Candidatus R. senegalensis-specific DNA. In addition, serological testing of 13 cats using a group-specific IgG-ELISA detected antibodies against typhus group rickettsiae and spotted fever group rickettsiae in six (46.2%) and one (7.7%) cat, respectively. These results indicate that cats and their fleas may have played an active role in the epidemiology of the typhus group and/or spotted fever group rickettsial disease(s) in this outbreak.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Average number of fleas (plus standard error) collected on glue boards (n = 36) from Sep to Nov 2015 at the mobile home community in San Gabriel Valley, California.
Fig 2
Fig 2. Abundance of outdoor wildlife and outdoor feeding sources from Jun to Nov 2015 at the mobile home community in San Gabriel Valley, California.
See this image and copyright information in PMC

References

    1. Azad AF, Radulovic S, Higgins JA, Noden BH, Troyer JM. Flea-borne rickettsioses: Ecologic considerations. Emerg Infect Dis. 1997; 3:319–327. doi: 10.3201/eid0303.970308 - DOI - PMC - PubMed
    1. Civen R, Ngo V. Murine typhus: An unrecognized suburban vector-borne disease. Clin Infect Dis. 2008; 46:913–918. doi: 10.1086/527443 - DOI - PubMed
    1. (CDPH) California Department of Public Health. Typhus and other non-spotted fever rickettsioses case report (CDPH working case definition, 2011). http://publichealth.lacounty.gov/acd/Diseases/EpiForms/TyphusOtherNonSpo... (Accessed February 2, 2018).
    1. Foo C, Croker C, Nelson K, Wekesa JW, Fujioka K, Civen R. An outbreak of flea-borne typhus associated with a mobile home community- Los Angeles County, California, 2015. Acute Communicable Disease Control Annual Report. http://publichealth.lacounty.gov/acd/Publications.htm
    1. (CDPH) California Department of Public Health. Flea-Borne Typhus. 2014 http://www.cdph.ca.gov/HealthInfo/discond/Documents/Flea-borneTyphus.pdf

Publication types

MeSH terms

Substances