29 November 2010
This report provides information on the surveillance of poultry undertaken by the EU MS. It is structured to provide summary information on sampling and results in addition to more detailed analysis.
All twenty-seven EU Member States (MS) participated in the survey in 2009. A total of 35,016 poultry holdings were sampled, which compares to 34,985 in 2008, 126,912 in 2007 and 29,005 in 2006. The most frequently sampled poultry category was Backyard Flocks (26.7% of total holdings sampled by EU MS), closely followed by Laying Hens (Free-range and conventional) (24.1%). The least sampled poultry category was Ratites (270, 0.77%) and this poultry category only makes up 0.04% of total holdings across the EU. In addition, two non-EU MS, Norway (NO) and Switzerland (CH), submitted data for this report.
In the 2009 survey of EU poultry for avian influenza evidence of previous infection with low pathogenicity avian influenza according to Directive 2005/94/EC was detected in 90 holdings (0.26% of total holdings sampled). In 2009, detections of antibodies to avian influenza according to Directive 2005/94/EC (H5 and H7 subtypes) occurred in Chicken Breeders, Laying Hens, Free Range Laying Hens, Fattening Turkeys, Backyard Flocks, Fattening Ducks, Breeder Ducks, Breeder Geese, Game Birds and Other Poultry. H5 was responsible for the majority of Duck and Geese positive holdings, whereas H7 subtypes were more common in Backyard Flocks in 2009.
In 2009 there were 52 holdings found positive for H5 by serological testing. A total of five holdings tested positive for subtype H5 by PCR or virus isolation; indicating that in 9.6% of the holdings positive for subtype H5, infection was still active. One holding tested positive for both subtypes on serology or PCR/ virology. These figures are higher than in 2008 when, for H5, four holdings (7.4%) and for H7, two holdings (9.5%) tested positive by PCR or virus isolation.
In 2009 there were 38 holdings found positive for H7 by serological testing. This is almost double the number of H7 when compared with 2008 (n=21). In 2009, sixteen holdings were positive for H7 subtypes by PCR or virus isolation,indicating that in 42% of the H7 positive holdings, the infection was still active.
Two MS (BE and FI) which detected AI positive holdings in 2008 did not find any positives in 2009. In comparison, there were three MS (IE, PL and RO) which detected positive holdings in 2009, but found none in 2008. In addition, non-EU MS Switzerland detected two positive holdings in 2009. Most (86.4%) of H7 positive holdings were detected in Italy, mainly in Backyard Flocks and Other holdings. The majority (58.2%) of H5 positive holdings were detected in France, particularly in Breeder Ducks and Fattening Ducks.
The detection rate in Breeder Ducks (9.1%) and Breeder Geese (8.3%) was considerably higher than other poultry categories across the EU, and Fattening Ducks had the third highest detection rate at 1.19%. The high rate of detections in these categories may be due to the following factors:
Ducks and geese are less likely to show clinical signs than other poultry species so infection is less likely to have been detected previously by passive surveillance, while in other species clinical disease due to AI may lead to removal of the flock. The Breeder Duck and Breeder Geese birds tend to have a longer lifespan than birds of other poultry categories, and therefore a longer time period in which they could have been exposed to the virus. Ducks and geese are frequently kept outdoors and therefore may have a higher probability of contact with wild birds, either directly or indirectly, and hence possibly a greater risk of exposure to AI virus. The last factor may also