CDC Case Challenge: Four People With Cough and Dyspnea After Attending a Baseball Game

Christina A. Nelson, MD, MPH; Katharine M. Cooley, MPH; David W. McCormick, MD, MPH


October 07, 2021

Editorial Collaboration

Medscape &

The most common manifestation of naturally occurring disease is bubonic plague, characterized by the presence of a painful, enlarged lymph node (bubo).[1,17,18] This clinical form occurs in approximately 80%-85% of plague cases. About 10% of patients with plague have the primary septicemic form and present with fever, chills, myalgia, abdominal pain, and other symptoms without localizing signs.[1,17] Primary pneumonic plague occurs in 3% of naturally occurring cases; patients typically present with cough; dyspnea; and, in severe cases, bloody sputum.[1,19] Secondary pneumonic plague can develop in patients with other clinical forms of the disease, via hematogenous spread of Y pestis to the lungs.[20] Other rare forms of plague include meningitis, pharyngitis, and ocular plague.[1]

Although pneumonic plague is uncommon as a naturally occurring clinical manifestation, the most likely route for intentional dispersal of Y pestis as a bioweapon would be through the air, leading to inhalation of the bacteria and primary pneumonic plague.[8,21] Pneumonic plague is the only clinical form of plague that can be transmitted from person to person, via large respiratory droplets.[20]

Pneumonic plague in this case challenge was caused by the patients' inhalation of Y pestis following an intentional release of the bacteria, presumably during the baseball game that all patients attended. Following inhalation of Y pestis, a patient is likely to develop symptoms similar to those of other respiratory infections, usually within 1-3 days after the exposure.[19,21,22] The early symptoms of pneumonic plague are nonspecific and could include headache, fever, chills, cough, and dyspnea. Most patients experience a dry cough initially that later becomes productive; sputum typically contains only a few bacilli at first, but as the disease progresses, sputum contains higher concentrations of Y pestis.[1]

Plague, although rare, remains a threat both as naturally occurring disease and as a bioterrorism agent. It is important that clinicians everywhere are able to recognize and treat patients with plague rapidly. Preparedness for response to a bioterrorism event is critical to ensure that all infected patients are treated or receive prophylaxis in a timely manner.