Former U.S. President Jimmy Carter says that Guinea worm disease may soon be eradicated, which would be the most exciting accomplishment of his career, although progress is hampered by ongoing conflict in Mali and South Sudan.

Carter has led a campaign since 1986 through his foundation, the Carter Center, to rid the world of the once-widespread disease. With only 22 cases worldwide last year, they may now be on the cusp of wiping it out forever. When the Carter Center began its campaign there were an estimated 3.5 million cases of the worm disease in 31 countries.

The 91-year-old Nobel Peace Prize winner spoke on a call to South Sudan from London. Carter is to address the House of Lords Wednesday to speak about the campaign against the Guinea worm.