Table 1.
Subtype characterization of porcine influenza viruses from selected swine holdings in Northwest Germany, 2009 to 2012a
| Subtype | No. of samples in: |
Total no. (% of all viruses [% of fully subtyped viruses]) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Study A (2009–2010) | Study B |
||||||||||||||
| Mo (2011) |
Mo (2012) |
||||||||||||||
| 3b | 4 | 5 | 6c | 7b | 8b | 9b | 10 | 11 | 12 | 1 | 2 | 3 | |||
| Fully subtyped viruses | |||||||||||||||
| H1N1 | 13 | 11 | 5 | 5 | 6 | 4 | 5 | 7 | 13 | 8 | 6 | 0 | 7 | 6 | 96 (38.6 [62.7]) |
| H1N2 | 7 | 3 | 1 | 0 | 2 | 2 | 4 | 3 | 0 | 1 | 1 | 0 | 1 | 2 | 27 (10.8 [17.6]) |
| H1N1pdm | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 (0.8 [1.3]) |
| H1pdmN2 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 2 | 0 | 2 | 0 | 0 | 5 | 1 | 11 (4.4 [7.2]) |
| H3N2 | 6 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 1 | 2 | 1 | 1 | 3 | 1 | 17 (6.8 [11.1]) |
| Sum | 26 | 14 | 7 | 6 | 10 | 7 | 9 | 12 | 14 | 13 | 8 | 1 | 16 | 10 | 153 (61.4 [100.0]) |
| Partially subtyped and nonsubtyped viruses | |||||||||||||||
| H1Nx | 10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 10 (4.0) |
| HxN1 | 0 | 2 | 2 | 2 | 1 | 2 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 2 | 13 (5.2) |
| HxN2 | 0 | 0 | 0 | 1 | 1 | 3 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 6 (2.4) |
| HxNx | 50 | 4 | 3 | 1 | 0 | 1 | 0 | 0 | 1 | 2 | 0 | 2 | 0 | 3 | 67 (26.9) |
| Sum total | 86 | 20 | 12 | 10 | 12 | 13 | 10 | 12 | 15 | 15 | 9 | 3 | 17 | 15 | 249 (100.0) |
a
In study A, viruses were detected in the lung tissues of weaners with severe respiratory disease. Study B samples consisted of nasal swabs from sows, piglets, or weaners from large holdings with fertility problems. Each sample represents one holding. Double infections were found in five cases.
b
A double infection with H1N1 and H1N2 was detected; both viruses were counted.
c
A double infection with H1N1 and H3N2 was detected; both viruses were counted.