Pneumonia is inflammation of the lungs, usually caused by a viral or bacterial infection. The pope has bilateral pneumonia, known informally as double pneumonia, and means both lungs are affected.

What is a polymicrobial infection? Polymicrobial infections are caused by multiple pathogens, including bacteria, fungi or parasites. These infections can cause both chronic and s

Pope Francis, 88, was hospitalized last Friday with bronchitis, the Vatican said, and now has a “polymicrobial infection of the respiratory tract.”