Dermatological manifestations of tick-borne viral infections found in the United States.

Tick-borne diseases (TBDs) are bacterial, viral, and parasitic diseases transmitted by ticks. Viral TBDs have increased in prevalence over the last decade with many new pathogenic viruses being discovered. Doxycycline is often empirically prescribed by clinicians to treat symptomatic patients following tick bites due to suspicions of bacterial TBDs such as Rocky Mountain spotted fever, anaplasmosis, and ehrlichiosis. However, viral TBDs are included in the differential diagnosis if patients do not clinically improve following antibiotic therapy. Several viral TBDs present with dermatological manifestations. Recognizing the differences in clinical presentations of TBDs, particularly of newly emerging viral TBDs in the United States, can help physicians identify the viral TBD, and possibly rule out viral illnesses with different clinical presentations. Therefore, this review discusses clinical manifestations, with an emphasis on dermatologic manifestations of Heartland Virus, Bourbon Virus, Powassan Virus, Deer Tick Virus and Colorado Tick Fever Virus. KEY POINTS: Viral tick-borne diseases have increased in prevalence over the last decade and often have similar clinical manifestations to other tick-borne diseases, including bacterial infections. Here, we review the dermatologic manifestations of Heartland Virus (HRTV), Bourbon Virus (BRBV), Powassan Virus (POWV), Deer Tick Virus (DTV) and Colorado Tick Fever Virus (CTFV) that are important for clinicians.

Molecular Detection of Rickettsia felis in Fleas of Companion Animals in East Texas.

Flea-borne spotted fever is an emerging insect-borne rickettsial infection caused by Rickettsia felis and has been identified worldwide. This study sought to explore the prevalence of rickettsiae associated with fleas on companion dogs and cats from Walker and Montgomery Counties in East Texas. Fleas were collected from animals entering local veterinary clinics for routine checkups. Collected fleas were identified as Ctenocephalides felis or Pulex irritans and analyzed by polymerase chain reaction for the presence of rickettsiae and subsequent sequencing. An estimation of the bcMLE (bias-corrected maximum likelihood estimation) of pooled samples was calculated. Four hundred eighty-eight fleas (comprising C. felis and P. irritans) were collected from 16 cats and 77 dogs. Our results demonstrate R. felis in 21 pools of fleas from dogs (bcMLE 15.28%) and a bcMLE of 7.25% from flea samples collected from cats. Sequence analysis revealed R. felis as the only Rickettsia that could be amplified in our samples using the rickettsial citrate synthase gene and subsequent sequencing. In this study, the presence of R. felis in fleas from companion cats and dogs suggests a potential risk of flea-borne spotted fever in humans who encounter flea-infested animals.