Table 1. Characteristics and diversity of GAS isolates under analysis.

Disease group	No. of isolates	Dates	Geographic origin	No. of emm types represented	D, based on emm type a	No. of emm subtypes represented	D, based on emm subtype
Pharyngitis	78	2001–2002	Bristol, CT	19	0.8998	27	0.9261
Pharyngitis	68	2012	Chicago, IL	14	0.9166	16	0.9289
Total pharyngitis	146	n/a	n/a	21	0.9125	34	0.9369
Impetigo	58	1994–1996	Australia	28	0.9782	29	0.9794
Impetigo	16	1971–1988	Worldwide	16	1.0000	16	1.0000
Total impetigo	74	n/a	n/a	39	0.9852	41	0.9863
Invasive	60	1995	CT	20	0.8667	n.d.	n.d.
ARF	42	1933–1989	USA	20	0.9489	34	0.9907
Total isolates	322	n/a	n/a	69	0.9530	96	0.9811

^a D, Simpson's diversity index