Bird flu in the Gelderse Valley spread from two companies

Since April 12, nine cases of bird flu have been identified in Lunteren, Barneveld, Terschuur and Voorthuizen, where about 485,000 poultry have been killed. Six times it was about laying poultry farms, twice about duck farms and once about a breeding farm.

Infection between companies

The WBVR analyzed the genetic code for the highly pathogenic H5N1 avian influenza virus on poultry holdings and concluded that cross-farm contamination has been identified. “This analysis shows that there are two clusters of infections. Within such a cluster, viruses are very closely related. So it is likely that two companies have been infected by wild birds, after which the virus managed to spread to companies nearby, Says Nancy Beerens, head of the Dutch reference laboratory for bird flu at WBVR.

She calls infection via the same bird group unlikely. “We can never rule out contamination from the same source based on genetic analyzes. If two companies get infected, this is a real possibility, but with four or five companies, this scenario becomes very unlikely. Furthermore, no large groups of wild birds infected on the Veluwe were found; there are of course few waterfowl in this region at all. The previous infections in the duck pond in Barneveld are also separate from the infections on the farms, these viruses are not closely related to the outbreak viruses. “

‘Stay aware of the hygiene protocols’

The genetic analysis therefore points to spread between farms. “The way in which viruses are spread is often not clarified, but in Lunteren, two companies were infected by the same owner. This also indicates that the virus is highly contagious and can be easily transmitted between companies. It is good to be aware of this so that poultry farmers remain very aware of the hygiene protocols and avoid all contact with other companies. That’s what it takes to get the outbreak under control quickly and prevent further spread. “

Already last week, Minister Staghouwer referred in a letter to the House of Representatives to possible infections from farm to farm in the Geldersedalen due to the large number of poultry farms in the region, the relatively short time frame in which the infections took place and the declining number of infected wild birds. “It therefore seems more likely here that the virus has spread between companies,” he said. It has now been confirmed by analysis of the genetic code of the virus.

Spraying during clearing

In addition, he stated in the letter to Parliament that NVWA is working to further improve the approval process. There were signs that a lot of dust was released during the clearings from NVWA. According to the minister, analyzes from researchers have not given any indication that the virus has spread to other companies through the killings. NVWA loads the carcasses into the stables where possible and reduces dust formation by spraying the killed animals with water during loading.

Prevent access

Minister Staghouwer also announced a tightening of the ban on visits to poultry farms in regions 7 and 10, the area from Utrecht to Zwolle and from Deventer to Arnhem. To prevent the introduction of the virus, visits are not only prohibited in animal shelters, but also in all other company buildings. Only necessary visits for animal welfare and animal health are allowed. Eggs can also be collected. The home is not covered by the restraining order.

National scenario

There will be a national manuscript on how to deal with sick wild birds. This was written by Minister Staghouwer and his colleague Ernst Kuipers from Public Health on Tuesday in a response to the eight-point bird flu plan from D66 MP Tjeerd de Groot. The various protocols available for the management of sick wild birds and the safe removal of dead wild birds are integrated into the national scenario. The manuscript will too best practice about clearing up dead wild birds with bird flu. These are supplied by the Friesland Safety Region.

In the plan, D66 is in favor of lowering the density of poultry holdings and reducing the number of animals per capita. Ministers say they have asked human and animal health experts to map the prevalence of animal diseases and zoonoses between farms. The size of the company is also taken into account. The answers from the experts are expected to be available this summer. “Next, it will be investigated how zoonosis risks are included in the integrated area-oriented approach in the context of nitrogen, water and climate,” according to Staghouwer and Kuipers.

Wetland

They also asked the WBVR to analyze which factors are important for the risk of avian influenza, such as the type of farm and the species of poultry. In recent years, it has already been shown that poultry farms in wetlands are at greater risk of becoming infected with bird flu.

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