Acquisition and transmission of spotted fever group Rickettsia in tick vector (Amblyomma maculatum)

Abstract

Spotted fever group (SFG) Rickettsia species, like Rocky Mountain Spotted Fever, are pathogens commonly associated with insect vectors. Ticks in particular are more commonly associated with SFG Rickettsia transmission. Because of their anthropomorphic feeding and broad habitation, ticks are the most effective insect transmitter of Rickettsia species to humans. However, the dynamics of Rickettsia species transmission between the ticks and the host are still unclear. Suwanbongkot et al. (2019) found differing amounts of Rickettsia species in the tick salivary glands, saliva, and in the vertebrate host tick feeding sites. They also identified a discernable lesion pattern in vertebrate hosts fed on by Rickettsia parkeri – infected ticks. However, they were unable to discern the transmission dynamics of Rickettsia species in ticks from their results. Further investigations need to test characterized rickettsial isolates and utilize a bioassay that controls for tick variables.