Table 1.

Frequencies of emm Types and emm Clusters Among 7040 Group A Streptococcus Isolates Recovered From Pharyngitis in the United States

emm Type	emm Cluster	No.	% of Isolates
			All Isolates	15 Most Frequent emm Types
2, 8, 22, 28, 73, 77, 89, 102, 114	E4a	1912	27.16	26.68
1, 163	A-C3a	1252	17.78	17.76
12	A-C4a	1236	17.56	17.56
4, 60, 78	E1a	696	9.89	9.62
3	A-C5a	614	8.72	8.72
11, 48, 63, 75, 94, 177	E6a	429	6.09	5.87
6	M6a	393	5.58	5.58
9, 44, 49, 58, 82, 87, 103, 118, 219	E3a	350	4.97	3.85
5	M5a	106	1.51	1.51
33, 41, 43, 53, 70, 83, 101, 119	D4	17	0.24
18	M18a	14	0.20
62, 68, 76, 92, 96, 110, 117	E2a	12	0.17
170, 205	E5	4	0.06
14	M14	1	0.01
57	M57	1	0.01
74	M74	1	0.01
234	M234	1	0.01
236	M236	1	0.01
		7040	100.00	97.15

The emm-type data originate from a previous study [9]. The 15 most frequent emm types are underlined.

^a Stands for the emm cluster in common with the Canadian collection (1434 isolates).