Here’s a good resource – http://emedicine.medscape.com/article/1007946-clinical#a0217
“Revised in 1992, the modified Jones criteria provide guidelines for making the diagnosis of rheumatic fever.[8] The Jones criteria require the presence of 2 major or 1 major and 2 minor criteria for the diagnosis of rheumatic fever. Having evidence of previous group A streptococci (GAS) pharyngitis is also necessary. These criteria are not absolute, and the diagnosis of rheumatic fever can be made in patients with only confirmed streptococcal pharyngitis and chorea.”