Experimental transmission of the relapsing fever spirochete Borrelia persica in its tick vector Ornithodoros tholozani by transstadial, transovarial, and hyperparasitism routes with description of dynamics within the tick host

This study shows that B. persica can be maintained transstadially and transovarially in a tick colony, although transovarial transmission occurred at low rates. Additionally, transmission of B. persica was experimentally shown to occur through hyperparasitism between O. tholozani ticks, a transmission pathway that is likely to occur also under natural conditions. Finally, we determined that B. persica colonized the salivary glands within a period of 4 weeks, and thereafter the tick may be considered as ready to infect a host. Improved understanding of tick colonization by spirochetes and pathways of transmission described here will help to form concepts to disrupt the infectious cycle of tick-borne relapsing fever.