What is ‘polymicrobial respiratory tract infection’ that Pope Francis is suffering from?

What is ‘polymicrobial respiratory tract infection’ that Pope Francis is suffering from?

Pope Francis’ hospitalisation continues as he is being treated with a ‘complex clinical’ condition, says the Vatican. He has been diagnosed with a ‘polymicrobial infection’ of his respiratory tract. What is this illness?

Pope Francis touches his forehead during his weekly general audience in the Paul VI Hall, at the Vatican. He is currently hospitalised after suffering a complex infection in his respiratory system. File image/AP