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Belgium: Learning from 2019 outbreak of low pathogenic AI

A large-scale outbreak of low pathogenic bird flu caused enormous damage in West Flanders, Belgium last year. At the Belgian agricultural fair Agridagen, poultry veterinarian Maarten de Gussem discussed the lessons he believes can be drawn from this outbreak.

He described the aftermath of the outbreak as “a serious hangover,” which is felt in large parts of the Belgian poultry industry. 82 poultry farms had to be cleared or voluntarily had their animals culled because of the low pathogenic H3N1 virus. It took months before official steps – with corresponding compensation – could be undertaken, as the virus was classed as low pathogenic with no mandatory procedures of stamping out in the procedures.

Veterinarian Maarten de Gussem states that diagnose of avian influenza is done, using outdated tests and methods. Photo: Vetworks
Veterinarian Maarten de Gussem states that diagnose of avian influenza is done, using outdated tests and methods. Photo: Vetworks

Only bird flu virus of the H5 or H7 subtype are notifiable

The main problem was the definition of variants subject to notification and control of Avian Influenza from world animal health organization OIE. According to those rules, only avian influenza viruses of the H5 or H7 subtype are currently required to report, and all highly pathogenic AI viruses. A virus is classed as highly pathogenic if a virus has a pathogenicity of 1.2 or higher. This was not the case with the Belgian H3N1 virus. However, this pathogenicity test is done – according to protocol – in young chicks, whereas this virus caused a great deal of mortality in older hens.

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OIE definitions still unchanged

Lessons can be learned from the outbreak, said Belgian poultry veterinarian Maarten de Gussem (Degudap / Vetworks). These lessons are not only relevant for Belgium, but also for other countries, as the OIE definitions are still unchanged and a similar situation could arise again. De Gussem expressed his concerns. “The OIE definition is by no means an accurate one. I place the “L” in LPAI in quotation marks, because this was certainly not a low pathogenic virus that wreaked havoc in Belgium. But if you ask the OIE for an adaptation of the definition, they say: it doesn’t go that fast. This is being discussed for years. I actually think it is a shame that they don’t seem to realise what the consequences of this policy have been. ”

De Gussem argues for mass eradication at an early stage and rapid detection using the latest techniques. He warned that large-scale stamping out is no longer accepted by society. De Gussem expressed his surprise that bird flu is still being diagnosed based on serological tests. “That is out of date. We depend on legal schemes and techniques, but they are, by definition, outdated when they are laid down by law. ” The sector must take matters into its own hands, says the poultry veterinarian, not waiting for the government.