Plague in the United States: the "black death" is still alive.

Plague is endemic in the western United States, but patients may present with plague anywhere in the country. Although human infections are rare, a missed diagnosis carries a mortality rate exceeding 50%, whereas prompt diagnosis and appropriate treatment reduce the case fatality rate to less than 5%. We present the case of a 55-year-old man treated for plague and review the diagnostic and therapeutic aspects of plague.