DOI: 10.1128/MMBR.67.3.473.2003
Volume 67, no. 2, p. 238-276, 2003. Page 242, column 2, line 26: “315.5” should read “315.6.”
Page 242, column 2, line 38: “315.6” should read “315.5.”
Page 243, Fig. 2: Both occurrences of “315.5” should read “315.6,” and both occurrences of “315.6” should read “315.5.”
