Plague was first introduced into the United States in 1900. Between 1900 and 2012,
1006 confirmed or probable human plague cases occurred in the United States. Over 80%
of United States plague cases have been the bubonic form. In recent decades, an average
of 7 human plague cases are reported each year (range: 1-17 cases per year). Plague has
occurred in people of all ages (infants up to age 96), though 50% of cases occur in
people ages 12–45. Worldwide, between 1,000 and 2,000 cases each year are reported to
the World Health Organization, though the true number is likely much higher.

Plague is easily treated with antibiotics.

[link to www.cdc.gov (secure)]

In short, pfffft.