TABLE 2

Summary of the serological survey from 20 virus-positive domestic swine farms by HI assay

Yr of sampling and farmNo. of sera positivea for B/Yamagata lineagebPositive (%)No. of sera positive for B/Victoria lineagecPositive (%)
2010-2011
    11-A0/2705/27 (557)18.5
    11-B0/1002/10 (905)20.0
    11-C0/701/7 (640)16.7
    11-D0/3001/30 (1,280)3.3
2012
    12-A0/1201/12 (40)8.3
    12-B4/12 (67)d33.31/12 (40)8.3
    12-E0/1605/16 (243)31.3
    12-G1/11 (40)9.10/110
    12-L1/13 (40)7.70/130
    12-T2/12 (40)16.70/120
    12-V1/12 (80)8.30/120
    12-W2/10 (40)20.00/100
    S12-A2/10 (40)20.01/10 (160)10.0
    S12-B5/10 (61)50.00/100
    S12-D1/10 (160)10.00/100
    S12-E1/10 (40)10.00/100
    S12-G0/1204/10 (48)40.0
    S12-J0/501/5 (320)20.0
    S12-K4/12 (40)33.30/120
    S12-S1/8 (1,280)12.51/8 (160)12.5
  • a Data are positive sample numbers out of the total number tested.

  • b Yamagata lineage B/Wisconsin/1/2010 was used.

  • c Victoria lineage B/Brisbane/60/2008 was used.

  • d Numbers in parentheses indicate geometric mean HI titers for samples with a value of ≥40.