3. household contacts of leprosy patients described in group 2. Blood, nasal swabs, slit skin smears, and biopsies will be taken from the volunteers to learn the strains of leprosy-causing bacteria in the area, the immune responses (body's response to disease) in local residents against the bacteria, and the pattern of leprosy transmission. Individuals will participate in this study for 1-10 days, and the study will last for 3 years.