rocky mountain spotted fever
(Science: infectious disease) An acute febrile (feverish) disease initially recognised in the rocky mountain states, caused by rickettsia rickettsii transmitted by hard-shelled (ixodid) ticks. Occurs only in the western hemisphere.
The disease is characterised by sudden onset of headache, chills and fever which can persist for 2-3 weeks, muscle pain. A characteristic rash appears on the extremities and trunk about the 4th day of illness.
The rickettsiae grow within damaged cells lining blood vessels which may become blocked by clots. Blood vessel inflammation (vasculitis) is widespread early recognition of the condition and prompt antibiotic treatment is important in reducing mortality.