Molecular and Immunological Tools for Detection of Strain Diversity, Drug Resistance and Immunological Responses

The purpose of this study is to determine what factors contribute to the continued incidence of leprosy in Colombia. Study participants will include volunteering and consenting individuals, older than 4 years of age, representing three study groups: 1. healthy persons with no known contact with leprosy patients 2. patients reporting at Instituto Colombiano de Medicina Tropical-CES and Impresa Social del Estado Sanatorio Agua de Dios with a new diagnosis of leprosy or relapse of leprosy 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.