Clinical characteristics of Rocky Mountain spotted fever in the United States: A literature review

Abstract

Background and objectives: Rocky Mountain spotted fever (RMSF) is a rapidly progressive and potentially fatal tickborne disease caused by Rickettsia rickettsii. Despite current recommendations and information on the severity of RMSF, studies show that delayed recognition and treatment continues to occur.

Methods: A literature search was performed on cases published in English between 1990-2017. The frequencies for demographic, clinical, and treatment variables was calculated.

Results: A total of 340 cases from 34 articles were included. Data on rash were available for 322 patients, and 261 (80%) noted rash. Mortality was 4% (2) in those who received doxycycline within the first five days of illness, and 35% (18) when treatment was delayed beyond Day five. Twenty-four (16%) reported chronic sequelae, including speech impairment (7, 5%) and ataxia (5, 3%).

Interpretation and conclusion: These data highlight the importance of early treatment, and add to our understanding of long-term sequelae. Early recognition by providers will facilitate appropriate treatment and reduction in morbidity and mortality.

Keywords: Rickettsia rickettsii; Rocky Mountain spotted fever; spotted fever group rickettsiosis; tickborne disease; vector borne disease.