Murine typhus is caused by Rickettsia typhi and is transmitted by the bite of rodent or cat fleas (Xenopsylla cheopis, and Ctenocephalides felis) or the inadvertent scratching of flea feces into wounds. The fleas are carried by rodents, opossums, cats, and dogs. Typhus is found worldwide. In the United States it most commonly occurs in California, New York, and the Gulf Coast states. It appears that R. typhi does not produce disease in cats and dogs like it does in people. There is also a louse-transmitted typhus which is caused by R. prowazekii, and is generally a more severe disease. Recently, a new causative agent of a typhus-like disease has been identified as Rickettsia felis. It appears to be carried by the cat flea, C. felis.

In people, typhus causes fever, chills, headache, and general pain. A rash sometimes develops on the body except for the face, soles of the feet, and palms of the hand. The disease is diagnosed through blood testing and is treated with tetracycline, doxycycline, or chloramphenicol. Prevention of the disease is through rodent and flea control.