Results of the SpaA416 ELISA with the 2.5-μg/ml antigen (A) and the latex agglutination test (B) with sera from 6- to 7-month-old fattening pigs in 1998, 1999, and 2000, just before the farm experienced an epidemic of acute swine erysipelas in 2000. The hatched columns, white-dotted columns, and clear columns represent the antibody titers of sera collected in each of the three years, respectively (n = 10 per year).