The funeral was scheduled for August 19 in Karachi, said Shariq Zaman, a spokesman for Pfau's charity.
"Dr Ruth Pfau", a symbol of selflessness and devotion to leprosy patients", passed away at 87 years old in Karachi late Wednesday night while she was experiencing surgery.
In his condolence message, Hussain said that Dr. Pfau had left her homeland and settled in Pakistan to serve humanity.
It was due to endless struggle of Dr Pfau that Pakistan defeated the disease and became free from leprosy in 1996.
Now her charity also runs projects in Afghanistan to train health workers. With the partnership of the Pakistani government, Pfau developed the country's National Leprosy Control Programme and extended her efforts to include treatments for blindness and tuberculosis.
In the 1950s she studied medicine in Germany.
Not required to take the veil or live in seclusion, she ended up in Pakistan by chance.
The President said the whole Pakistani nation salutes Dr Pfau for her exemplary services for the country. She was granted Pakistani citizenship in 1988. She didn't confine her endeavors to treating leprosy patients but at the same time was of colossal help when Sindh confronted serious flooding.
Dr Pfau, 87, who was suffering from complications related to old age, had been admitted to the Aga Khan Hospital two weeks ago where her condition was pronounced unstable.
She later joined a religious order, which sent her to India. Pfau is scheduled for August 19 at St Patrick's Cathedral in Karachi and she will be laid to rest at the Christian cemetery in the city.
And she received a number of honors, including, in 1979, Pakistan's second highest civilian award: the Hilal-e-Imtiaz; in 1989 she received the Hilal-e-Pakistan and the German Staufer Medal in 2015.
"With great concern we have got the sad massage of the death of Dr Ruth Pfau".