in half of all cases within the first week of infection and in nearly all cases by day-15. The sharing of antigens by rickettsiae means routine serologic evaluation will not distinguish between murine typhus and epidemic typhus. Bacterial cultures are rarely performed because although they are highly accurate for diagnosis, the biohazard risk of generating them is often considered too high. Treatment The disease can be fatal if left untreated, but endemic typhus is highly treatable with antibiotics. Most people recover fully, but death may occur in the elderly, severely disabled or patients with a depressed immune system. The most effective antibiotics include tetracycline and chloramphenicol. In the United States, the CDC recommends solely doxycycline. See also List of mites associated with cutaneous reactions References External links Bacterium-related cutaneous conditions Typhus