Differences in the socioeconomic standards of living remain an important and feasible partial explanation for the difference in incidence of rheumatic fever following GABHS infection in Egyptian compared with American children. However, past and ongoing studies of the epidemiology, diagnosis, and treatment of GABHS infections in Egypt, the United States, and elsewhere suggest other significant factors are relevant. Additional knowledge about the rheumatogenic GABHS serotypes that are most prevalent in all countries is an important area where additional research is needed. Streptococcal research will help not only in improving the quality of primary prevention of rheumatic fever, but also in developing streptococcal vaccines.