Figure 1.

Progress of highly pathogenic avian influenza (HPAI) outbreak by time, South Korea, 2010–2011. A) HPAI-positive cases identified from samples collected November 26–December 28, 2010 (wild birds, 6 cases). B) Cases identified by January 4, 2011 (wild birds, 10 cases; poultry, 2 cases). C) Cases identified by January 11, 2011 (wild birds, 13 cases; poultry, 23 cases). D) Cases identified by May 16, 2011 (wild birds, 20 cases; poultry, 53 cases). Blue circles indicate locations where HPAI viruses were isolated from wild birds; red circles indicate locations where HPAI viruses were isolated from poultry.