Legionnaire’s disease is a respiratory tract infection caused by the Legionella bacteria. The infection can be characterized by fever, chills, cough, and diarrhea. It typically affects males, the elderly, the immunocompromised, and those with underlying lung disease. Legionella thrives in water and can cause outbreaks through infected air conditioning systems, showers, and fountains.

The disease derived its name from a 1976 outbreak at an American Legion convention in Philadelphia.

Endocarditis is an inflammation of the cardiac endothelium. There are infective and non-infective forms.

Duke Criteria

The Duke criteria were established in 1994 by the Duke Endocarditis Society. These criteria serve as guidelines for the diagnosis of infective endocarditis. To be diagnosed with endocarditis, the patient must fulfill two major criteria, one major and three minor criteria, or five minor criteria.

The criteria listed below are abbreviated.

Major Criteria

• Sustained positive blood culture(s) by an organism known to cause endocarditis
• Endocardial involvement either via a positive echocardiogram (i.e., vegetation, abscess, prosthetic dehiscence) or a new valvular regurgitation

Minor Criteria

• Fever > 38^oC
• Predisposing condition (e.g., IV drug use, abnormal valve)
• Vascular phenomena, such as septic or pulmonary emboli, mycotic aneurysms, Janeway lesions, conjunctival hemorrhages
• Immunologic phenomena, such as glomerulonephritis, positive Rheumatoid Factor, Osler’s nodes, Roth spots
• Positive blood culture that does not meet a major criterion