Nelson Mandela recovers from lung infection and gallstone surgery Nelson Mandela spent most of December in hospital - his longest stay since being released from prison in 1990. Photograph: Gianluigi Guercia/AFP/Getty Images Nelson Mandela has recovered from a lung infection and surgery to remove gallstones that kept him in hospital for nearly three weeks, the government said on Sunday. The 94-year-old former South African president, who has been in frail health for several years, spent most of December in a Pretoria hospital - his longest stay for medical care since his release from prison in 1990. He has been receiving treatment at his Johannesburg home since leaving hospital on Boxing Day. "President Mandela has made steady progress and clinically he continues to improve," the South African presidency's office said in a statement. He has recovered from his surgical procedure and the lung infection, it said, citing his medical team. Nobel peace prize laureate Mandela has a history of lung problems dating back to when he contracted tuberculosis as a political prisoner. He spent 27 years in prison, including 18 years on Robben Island, off Cape Town. He became South Africa's first black president after the first all-race elections in 1994 brought an end to apartheid.