Manifestations and Management of Flea-Borne Rickettsioses

• Main Authors: Caravedo Martinez MA, Ramírez-Hernández A, Blanton LS
• Format: Article in Journal/Newspaper
• Language: English
• Published: Dove Medical Press 2021
• Subjects: rickettsia typhi; murine typhus; endemic typhus; flea-borne typhus; rickettsia felis; flea-borne spotted fever; rickettsiosis; Arctic medicine. Tropical medicine; RC955-962; Arctic
• Online Access: https://doaj.org/article/1fe515498313482f9c5032ff2984130b

Maria A Caravedo Martinez,1 Alejandro Ramírez-Hernández,2 Lucas S Blanton1 1Department of Internal Medicine – Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA; 2Department of Pathology, University of Texas Medical Branch, Galveston, TX, USACorrespondence: Lucas S Blanton 301 University Boulevard, Galveston, TX, 77555-0435, USATel [phone]Fax [phone]Email [e-mail]: Murine typhus and flea-borne spotted fever are undifferentiated febrile illnesses caused by Rickettsia typhi and Rickettsia felis, respectively. These organisms are small obligately intracellular bacteria and are transmitted to humans by fleas. Murine typhus is endemic to coastal areas of the tropics and subtropics (especially port cities), where rats are the primary mammalian host and rat fleas (Xenopsylla cheopis) are the vector. In the United States, a cycle of transmission involving opossums and cat fleas (Ctenocephalides felis) are the presumed reservoir and vector, respectively. The incidence and distribution of murine typhus appear to be increasing in endemic areas of the US. Rickettsia felis has also been reported throughout the world and is found within the ubiquitous cat flea. Flea-borne rickettsioses manifest as an undifferentiated febrile illness. Headache, malaise, and myalgia are frequent symptoms that accompany fever. The incidence of rash is variable, so its absence should not dissuade the clinician to consider a rickettsial illness as part of the differential diagnosis. When present, the rash is usually macular or papular. Although not a feature of murine typhus, eschar has been found in 12% of those with flea-borne spotted fever. Confirmatory laboratory diagnosis is usually obtained by serology; the indirect immunofluorescence assay is the serologic test of choice. Antibodies are seldom present during the first few days of illness. Thus, the diagnosis requires acute- and convalescent-phase specimens to document seroconversion or a four-fold increase in antibody ...