Investigating Anaplasma and Borrelia Rates in North Central West Virginia Ticks

Abstract

Ixodid (Acari: Ixodidae) ticks are widespread, diverse, and known as carriers of several important diseases. Lyme borreliosis is the most common tick-borne illness reported in West Virginia with more than 100 cases per 100,000 WV residents. Anaplasmosis is a bacterial infection caused by Anaplasma phagocytophilum which can also be carried by Ixodes scapularis ticks. In humans, Anaplasmosis may mimic other common infections, but can develop severe complications if left untreated. Anaplasma may also infect household pets such as cats and dogs. Anecdotal reports of Anaplasmosis in animals have increased dramatically in the last few years. The WV Office of Epidemiology and Prevention Services Vector Borne Disease reports that human cases of anaplasmosis tripled from 2022 to 2023. Ixodes ticks previously tested for Borrelia were retested for Anaplasma using real-time PCR analysis. Our data show a 2% Borrelia infection rate across 899 tested ticks. In addition, we detected a 17% Anaplasma infection rate in 388 tested ticks, with one instance of coinfection. These data suggest that there may be a higher incidence of Anaplasma infection than Borrelia in the same sample population of ticks. Through this research we will continue to track the changing rates of tick infection in order to better communicate vector-borne disease risks to the local community.