The Los Angeles County Department of Public Health is investigating a localized outbreak of flea-borne typhus in the Pico-Union neighborhood as cases continue to rise across Los Angeles County. Flea-borne typhus can be effectively treated with antibiotics when diagnosed early and it can be prevented with simple steps. Know the symptoms: Flea-borne typhus can cause fever, chills, headache, and rash. About Flea-Borne Typhus (Typhus) Typhus is an acute febrile bacterial infection caused by Rickettsia Typhi bacteria, which is spread by infected fleas. Infected animals typically do not show signs of illness, and flea-borne typhus is not spread from person to person.