Alternative definition : NICHD: An infection that is caused by certain species of Rickettsia or Borrelia, which
are transmitted to humans from infected ticks; it is characterized by sudden fever,
chills, headaches, myalgia, arthralgia, nausea, and possibly a rash. Symptoms usually
persist for two to nine days, then disappear, with recurrence after several weeks
if the patient remains untreated.;