| PCR Positive samples/tested samples (%) | Real-time PCR | |
---|---|---|---|
Ct value | rDNA copy number/ body weight (g) | ||
May | 36/90 (40.0%) | 38.9–41.4 | 2.5 × 103–1.6 × 103 |
June | 14/62 (22.6%) | 35.5–38-3 | 2.0 × 103–2.1 × 104 |
July | 5/126 (4.0%) | nd | nd |
August | 0/84 | nd | nd |
September | 0/82 | nd | nd |
October | 0/62 | nd | nd |
November | 0/72 | nd | nd |
 | 55/578 (9.5%) |  |  |