The second most abundant bacteria were Rickettsia species, which the research team said could indicate that they have a "symbiotic" relationship with ticks which is currently unknown to science.

A team of biomolecular engineers, pathologists, and internal medicine specialists at the University of Texas Medical Branch, ...

The second most abundant bacteria were Rickettsia species, which could indicate that they have a symbiotic relationship with ticks, which is currently unknown to us. Parasitizing migrating birds ...

SFRs vary in presentation, from mild to fatal, depending on the species of tick, however, early symptoms are non-specific.