It is not known exactly how Hansen’s disease spreads between people. Scientists currently think it may happen when a person with Hansen’s disease coughs or sneezes, and a healthy person breathes in the droplets containing the bacteria. Prolonged, close contact with someone with untreated leprosy over many months is neededto catch the disease. You cannot get leprosy from a casual contact with a person who has Hansen’s disease like: Shaking hands or hugging; Sitting next to each other on the bus and Sitting together at a meal. Hansen’s disease is also not passed on from a mother to her unborn baby during pregnancy and it is also not spread through sexual contact. Due to the slow-growing nature of the bacteria and the long time it takes to develop signs of the disease, it is often very difficult to find the source of infection.