This market will resolve to "Yes" if a confirmed case of pneumonic plague in a human is reported in the United States at any point between market creation and the specified date, 11:59 PM ET. Otherwise, this market will resolve to "No".

A "confirmed case" is a case explicitly identified by a qualifying source as laboratory-confirmed Yersinia pestis infection with pneumonic (pulmonary) involvement, or explicitly announced as a confirmed pneumonic plague case. Publication of the underlying laboratory results is not required. A bubonic or septicemic case that progresses to pneumonic plague qualifies. A case reported only as "plague" with no form specified, and a case described only as suspected or probable, do not qualify.

For the purposes of this market, the United States includes the 50 states and the District of Columbia. A case qualifies if the patient is diagnosed in the United States, regardless of where the infection was acquired. Cases diagnosed outside the United States, including in U.S. citizens abroad, do not qualify.

The case does not need to be epidemiologically linked to the Irkutsk outbreak or any other specific outbreak to qualify.

Resolution turns on the date a qualifying source publishes the confirmation, not the date of exposure, symptom onset, or laboratory result. A report published after the deadline does not count even if the infection occurred earlier.

The primary resolution sources for this market will be official information from the U.S. Centers for Disease Control and Prevention (CDC), U.S. state or local public health authorities, and the WHO; however a consensus of credible sources will also suffice.