Typhus

       Typhus is caused by one of two types of bacteria: Rickettsia typhi or Rickettsia prowazekii.

Rickettsia typhi causes murine or endemic typhus.

• Endemic typhus is uncommon in the United States. It is usually seen in areas where hygiene is poor and the temperature is cold. Endemic typhus is sometimes called "jail fever." The bacteria that causes this type is usually spread by rats to fleas to humans.
• Murine typhus occurs in the southern United States, particularly California and Texas. It is often seen during the summer and fall. It is rarely deadly. You are more likely to get this type of typhus if you are around rats feces or fleas, and other animals  such as cats, opossums, raccoons, and skunks.

Rickettsia prowazekii causes epidemic typhus. It is spread by lice. Brill-Zinsser disease is a mild form of epidemic typhus.  It occurs when the bacteria re-activates in a person who was previously infected. It is more common in the elderly.