Former Democratic Senator Daniel Patrick Moynihan of New York is in critical condition at a Washington hospital -- where he contracted an infection after an emergency appendectomy.

His former chief of staff Tony Bullock -- now Washington, D.C. Mayor Tony Williams' spokesman -- says Moynihan had the surgery last Tuesday at Washington Hospital Center, where he remains. Things had been going well until an infection set in Thursday.

But Bullock says doctors believe they've now got it under control.

Moynihan, who turned 76 on Sunday, has been in poor health in recent months.

He was hospitalized in January for an intestinal disorder and soon after that for a back injury.

Moynihan served four terms in the Senate until he retired in 2000. Hillary Rodham Clinton succeeded him in 2001. He's now a senior scholar at the Woodrow Wilson Center in Washington.