The world\'s oldest person , an Iowa woman who scrubbed floors until she turned 90,died Monday at age 115, less than two weeks after earning her venerable distinction. Dina Manfredini, a native of Italy, died at the Bishop Drumm Retirement Center outside Des Moines, Iowa, said its director, Heather Rehmer. She declined to give details. Manfredini was mainly a mother and homemaker but later in life took up working cleaning people\'s houses and kept at it until age 90, says the website of the Guinness Book of World Records. The widow lived independently up to the age of 110. The Guinness people had declared her pinnacle status only on December 5 of this year, a day after the death of an American lady named Besse Cooper, aged 116, in a nursing home nearly Atlanta, Georgia. Manfredini\'s family attributed her longevity to hard work and doing everything in moderation, the website said. The passing of Manfredini apparently leaves a Japanese man, Jiroemon Kimura, as the world\'s oldest person. He was born just 15 days after Manfredini. Her birthday was April 4, 1897.