This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The main purpose of this study is to determine if there are certain clinical and historical findings in the child from ages 3 months to 5 years which would more accurately predict a positive pharyngeal culture for Group A Streptococcal (GAS). Two additional aims of this study are as follows: to determine the true incidence of GAS upper respiratory infection in the young child (3 months to 5 years of age), and to determine the optimal site for culture and rapid antigen testing in the same age group (nasal versus pharyngeal).