Fast Five Quiz: Bites and Stings

Richard H. Sinert, DO


April 29, 2019

The reference standard for diagnosis of tickborne rickettsial diseases is the indirect IFA assay, using paired serum samples obtained soon after illness onset and 2-4 weeks later. Demonstration of at least a fourfold rise in antibody titer is considered confirmatory evidence of acute infection.

Patients usually do not have diagnostic serum antibody titers during the first week of illness, and a negative IFA assay or ELISA result during this period does not exclude the diagnosis of tickborne rickettsial diseases.

Delay in treatment of tickborne rickettsial diseases can lead to severe disease and death. Doxycycline is recommended by the American Academy of Pediatrics and Centers for Disease Control and Prevention as the treatment of choice for patients of all ages, including children younger than 8 years, with a suspected tickborne rickettsial disease. In persons with severe doxycycline allergy or who are pregnant, chloramphenicol may be an alternative treatment for Rocky Mountain spotted fever; however, persons treated with chloramphenicol have a greater risk for death than those treated with doxycycline. Chloramphenicol is not an acceptable alternative for the treatment of ehrlichiosis or anaplasmosis. For mild cases of anaplasmosis, rifampin might be an alternative to doxycycline for patients with a severe drug allergy or who are pregnant.

Read more on guidelines for the diagnosis and treatment of tickborne rickettsial diseases.


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