Vatican spokesman Matteo Bruni said the results of tests conducted in recent days and Monday indicate the pope is suffering from a “polymicrobial respiratory tract infection” that has necessitated a further change in his drug therapy. Scientists say polymicrobial diseases are caused by a mix of viruses, bacteria, fungi and parasites.

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

Pope Francis has developed pneumonia in both lungs, according to the Vatican, which said that the 88-year-old pontiff’s medical conditions present a “complex picture.”  “The laboratory