Protocol for selection of participants for RhFFUS. “Rural locations” comprise those communities involved in the gECHO that are outside of the cities of Cairns and Darwin. “Urban locations” comprise communities involved in the gECHO study that are within the cities of Cairns and Darwin. “RhFFUS inclusion criteria” are outlined in the text. “Non-Indigenous” refers to subjects enrolled in the gECHO project who self-reported as not being Aboriginal and/or Torres Strait Islander. “Definite RHD” is defined by WHF criteria . “CHD” refers to a diagnosis of congenital valvular heart disease that may generate morphologic or functional abnormalities similar to RHD (bicuspid aortic valve, dilated aortic root, mitral valve prolapse). “Case or Control” criteria are defined in the text.