The plague is endemic in fleas on rodents and small wild animals
in the US Southwest. Most people who contract it are
first treated with antibiotics after presenting with
the typical symptoms, and only a few days later
do the test results confirm the presumed diagnosis.
The riskiest situation is exposure to plague and then quickly traveling to some other location where plague is rarely seen, and doctors at the destination do not know to look at the symptoms as possibly plague, and to tentatively treat for plague before testing confirms the diagnosis. Medical groups in New Mexico have several time done public awareness programs using the tag line: “Land of the flea, home of the plague.”