Pope stable in hospital with respiratory infection as doctors treat 'complex' issue, Vatican says

Doctors have changed treatment for Pope Francis's respiratory tract infection to tackle a "complex clinical situation" and he will remain in hospital for as long as necessary, the Vatican said on Monday.

In an evening update, the Vatican said the 88-year-old was in stable condition, with no fever.

The pontiff was admitted to Rome's Gemelli hospital on Friday. He's had a respiratory infection for more than a week.

"The results of the tests carried out in recent days and today [Monday] have demonstrated a polymicrobial infection of the respiratory tract, which has led to a further modification of the therapy," a brief statement said.

"All tests conducted up to today are indicative of a complex clinical picture that will require an appropriate hospital stay."

Vatican spokesperson Matteo Bruni said the pontiff was "in good spirits." He did not specify whether the Pope was suffering from a bacterial or viral infection.

While a bacterial infection can be treated with antibiotics, viral infections cannot. Viruses usually have to run their course, but the patient can be assisted with other medicines to bring down their fever or help their body fight the infection.

A polymicrobial infection is caused by two or more micro-organisms, and can be caused by bacteria, viruses or fungi.

Rev. Dr. Andrea Vicini, a Jesuit priest and medical doctor, said polymicrobial is a generic term that does not specify an infection's root cause.

Vicini, who said he did not have knowledge of the Pope's case beyond the Vatican's public statements, also said it was notable that the Vatican had said earlier on Monday that the Pope ate breakfast, indicating that he was not on a respirator.

"It also means the body is not debilitated to the point of not being able to take food and digest it," said Vicini, a professor at Boston College.

Francis, who has been pontiff since 2013, has had influenza and other health problems several times over the past two years. As a young adult he developed pleurisy and had part of one lung removed, and in recent times has been prone to lung infections.

The Vatican said on Monday that the Pope's planned weekly audience in St. Peter's Square, set for Wednesday, had been cancelled "due to the continued hospitalization of the Holy Father."

The Pope's doctors had earlier ordered complete rest, and Francis was unable to deliver his regular weekly prayer on Sunday to pilgrims in St, Peter's Square or lead a special mass for artists to mark the Catholic Church's Jubilee Year.

'Quite worried' by Pope's absence

Pilgrims visiting the Vatican on Monday offered their hopes that Francis would recover soon.

"We certainly wish for him to get better very quickly," said Rev. Tyler Carter, a Catholic priest from the United States. "He is our father and our shepherd, and so we want his continued health and blessing."

Manuel Rossi, a tourist from Milan, said he was "quite worried" when the pope cancelled his appearance on Sunday.

"I am 18 years old so I have seen few popes in my life, and am very close to him," said Rossi. "I hope he recovers as soon as possible."

While in hospital over the weekend, Francis continued his recent practice of making phone calls to speak with members of a Catholic parish in Gaza, Italian broadcaster Mediaset reported on Monday.

One of the parish members said Francis had called on both Friday and Saturday, and was in "good spirits" but sounded "a bit tired."

"Pope Francis is touched by the numerous messages of affection and closeness that he continues to receive during these hours," the Vatican said Monday.