Typhus, spotted fever, and scrub typhus share which of the following manifestations of disease?

Typhus, spotted fever, and scrub typhus are all caused by rickettsiae (R. prowazekii, R. rickettsii, and R. tsutsugamushi, respectively). Clinically, the diseases have several similarities. Each has an incubation period of 1 to 2 weeks followed by a febrile period, which usually includes a rash. During the febrile period, rickettsiae can be found in the patient's blood and there is disseminated focal vasculitis of small blood vessels. The geographic area associated with these diseases is usually different. Scrub typhus is usually found in Japan, Southeast Asia, and the Pacific, while spotted fever is usually found in the Western hemisphere. Typhus has a worldwide incidence.