An individual must be exposed to an HD patient for a lengthy period of time to actually catch the disease. Even then, only 5 % of individuals exposed actually become HD positive. To prevent catching Hansen's disease it is best to avoid contact with individuals while they are going through the contagious state of the disease. Infected individuals should remain in isolation until the contagious period has passed (usually three weeks after treatment has begun). Avoid travel to those areas of the world that are considered unsanitary and underdeveloped.