The clinical manifestations of louse-borne typhus are similar to other common febrile illnesses in Ethiopia, including relapsing fever. After an incubation period of about one to two weeks the symptoms begin suddenly, with severe headache and fever rising rapidly to 38.8ºC to 40.0ºC. But unlike RF, the high temperature in typhus is sustained throughout the illness and the symptoms do not spontaneously improve and then relapse. A prominent cough is very common, occurring in 70% of patients. They also experience very severe muscle pain, sensitivity to light, lethargy and falling blood pressure. If untreated, the most severe cases end in coma and death.