The Brazilian man whose "miraculous" cure from a brain infection paved the way for Mother Teresa's canonisation this weekend said he is grateful for his life but does not feel particularly chosen by God.

Marcilio Haddad Andrino told a Vatican press conference he is just one example of God's ample mercy and love.

"The merciful Lord looks at us all without distinction," Mr Andrino said. "Maybe it was me this time but maybe tomorrow it will be someone else. The merciful mother looks after everyone. I don't feel special."

Pope Francis decreed in December that Mr Andrino's cure was a miracle after Vatican doctors and theologians determined that it was medically inexplicable, instantaneous, lasting and due to the intercession of Mother Teresa, who died in 1997.

It was the final step needed to canonise the nun who cared for the poorest of the poor.

Vatican spokesman Greg Burke said all 100,000 tickets have been distributed for Sunday's Mass but the crowd will probably be far greater, spilling into the main streets around St Peter's Square. So far, 15 official delegations have confirmed their presence, 13 led by heads of state or government, and 600 journalists have been accredited.

Mr Andrino's wife, Fermanda Nascimento Rocha, recalled that she and her family began fervently praying for Mother Teresa's intercession after receiving a relic of the nun on September 5 2008, after Mr Andrino began suffering from the effects of a viral brain infection.

By December that year, despite powerful antibiotics, the brain abscesses and fluid had built up so much that he was suffering debilitating headaches. According to the official story, doctors decided the only chance was to operate, but on the day surgery was scheduled, they couldn't intubate him.

"When the doctor left the OR saying he couldn't do the operation - and that the medicine wasn't working any more - I prayed a lot," Ms Nascimento Rocha said. "I asked Mother to cure Marcilio if this is God's will, and if not, to take him by the hand and bring him to the house of the Father to feel his caress."

She said she went to her mother's home and prayed "with all the strength I had".

When the surgeon returned to Mr Andrino's room, he was awake, pain-free and asymptomatic, according to the priest spearheading Mother Teresa's sainthood cause, the Rev Brian Kolodiejchuk.

Within six months, Mr Andrino had returned to work. Soon after, the couple conceived the first of their two children, though Mr Andrino had been told that the powerful drugs he had taken had made him infertile.

He calls his two children "the extension of that miracle", adding: "We are very grateful to Mother Teresa for our family."