Table 2. Presence of pandemic H1N1 influenza virus by qRT-PCR in samples collected at 3, 5, and 7 days post infection (dpi).* .
| Day | Virus | Lung | Tonsil | LN | Serum | Spleen | Liver | Kidney | Feces | Muscle |
| 3 dpi | CA/09 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| MX/09 | 5 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 5 dpi | CA/09 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| MX/09 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 7 dpi | CA/09 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| MX/09 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
*
15 pigs were infected with either the A/CA/04/2009 (CA/09) or A/Mexico/4108/2009 (MX/09) pandemic H1N1 virus isolates. Number of pigs positive out of 5 is reported from each group euthanized on 3, 5, or 7 dpi; LN = inguinal lymph node tissue sample.