A patient residing in New Mexico had murine typhus diagnosed. A novel molec
ular assay was performed at the Centers for Disease Control and Prevention,
and Rickettsia prowazekii, the agent of epidemic typhus, was found, rather
than R. typhi. To our knowledge, this is the first reported case of epidem
ic typhus confirmed by means of polymerase chain reaction-based testing of
cerebrospinal fluid, and it introduces a novel assay for the molecular diag
nosis of both epidemic and murine typhus.