Tick Transmission of Rickettsiae Faster Than Previously Thought

Fed, Rickettsia rickettsii–infected nymph and adult ticks can transmit this bacterium to guinea pigs in as little as 10 minutes.

Clinicians are taught that to transmit Rickettsia rickettsii — the cause of Rocky Mountain spotted fever — an infected tick must feed for ≥2 hours. To assess whether this interval is affected by the physiological state of the tick, investigators in Brazil conducted experiments with Amblyomma aureolatum ticks (the main vector of R. rickettsii in São Paulo).

Unfed, R. rickettsii–infected tick nymphs and adults were allowed to feed on guinea pigs for periods ranging from 2 hours to >90 hours. In addition, infected adult ticks that had fed for 48 hours on rabbits were removed and allowed to feed on uninfected guinea pigs for periods from 1 minute to >160 hours.

With unfed nymph and adult ticks, the shortest period that resulted in transmission of…

Reviewing Author

Mary E. Wilson, MD

Disclosures

Consultant/Advisory BoardOneHealthTrust (formerly Center for Disease Dynamics, Economics, and Policy); Global Health Institute, University of Wisconsin

RoyaltiesUpToDate

Editorial BoardsJournal of Travel Medicine

Mary E. Wilson, MD

Disclosures

Consultant/Advisory BoardOneHealthTrust (formerly Center for Disease Dynamics, Economics, and Policy); Global Health Institute, University of Wisconsin

RoyaltiesUpToDate

Editorial BoardsJournal of Travel Medicine

Tick Transmission of Rickettsiae Faster Than Previously Thought

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Reviewing Author