Natalina De Santis’ three adult children come to her front door, bringing food to keep her healthy and books to relieve her boredom, but she doesn’t let them in any more. Widowed a few months ago and living alone, the 83-year-old resident of Rome is so afraid of catching the coronavirus that she foregoes all visits as the disease that is especially deadly for the elderly grips Italy. “If I get sick, what would my children do?” she said in a telephone interview.