Table 1 Number of observations and corresponding proportions of classical and emerging strains.
2004 | 2005 | 2006 | 2007 | 2008 | |
---|---|---|---|---|---|
# observations | 67 | 64 | 68 | 50 | 40 |
# infected samples | 408 | 371 | 422 | 280 | 212 |
Classical strain (%) | 55 | 45 | 28 | 17 | 14 |
Emerging strain 1 (%) | 21 | 23 | 22 | 37 | 27 |
Emerging strain 2 (%) | 13 | 18 | 23 | 21 | 32 |
Emerging strain 3 (%) | 1 | 4 | 3 | 5 | 3 |
Emerging strain 4 (%) | 10 | 10 | 24 | 20 | 24 |