The washlet I have has a dryer function but it doesn't work all that well. I'm told this is pretty common and most people still need to use some paper to dry themselves. There's far less risk of fecal contamination of your hands while drying yourself after having your backside washed but it's still a possibility that when multiplied over an entire population means there are many people walking around with contaminated hands, especially if hand washing isn't the cultural standard.