Rickettsia Felis Case Cluster in a Military Family.

Abstract

Cases of flea-borne spotted fever (FBSF) have been on a steady increase in the southern United States and produce the highest numbers of reported vector-borne disease cases in Texas. Historically, cases were largely murine typhus caused by Rickettsia typhi and characterized by exposure to rodent fleas. However, more recently, spotted fever rickettsiosis caused by R. felis and characterized by exposure to the cat flea, Ctenocephalides felis, may be the dominant disease. We describe the management of a child with a complex clinical picture, including sickle cell β-thalassemia, bullous pemphigoid, and initially diagnosed with murine typhus infection. We also explain the clinical response to a case cluster of FBSF (R. felis) among a military family residing in on-post housing and the quantitative polymerase chain reaction testing of associated flea samples to confirm the pathogen species. This case cluster highlights some of the important challenges faced in managing the re-emergence of FBSF in the United States including: (1) difficulty diagnosing FBSF, (2) lack of resources to determine the specific pathogen involved, (3) vertical transmission of R. felis in fleas, and (4) the importance of effective coordination between medical providers and public health personnel with pest management professionals to ensure effective control of the fleas. FBSF presents a risk to the health and morale of military personnel stationed in the region and potentially a risk to operational effectiveness.