Infectious diseases clinic

Management of rickettsial diseases and Q fever

Stephen Graves



Australian rickettsial diseases (spotted fevers and typhus) and Q fever are readily treated with antibiotics. The greatest challenge may be to suspect the diagnosis in a patient with fever.

Article Extract

What are rickettsiae? Despite their name, they have nothing to do with rickets. Rickettsiae are bacteria named after Howard Ricketts, an early investigator and victim of typhus. These bacteria have some unusual properties:

  • They live inside animal (and human) cells as obligate intracellular bacteria.
  • They infect the cells of both arthropod invertebrates (e.g.lice, fleas, mites and ticks) and vertebrates (e.g. rats, mice, cats and humans).
  • They are transmitted from infected invertebrates to humans through a bite or the invertebrate’s faeces, which may be rubbed into a bite site or inhaled into the lungs.
  • They do not grow on agar plates in the microbiology laboratory.
  • Figures