A polecat runs across a brown tiled floor in a Rotterdam bird sanctuary in early 2022. Its head twists wildly, its body jerks in all directions – as if it were having an epileptic fit. A few seconds later, the creature lies plump on its side, its legs stiff in the air. The animal was euthanized. Research later revealed what was wrong with the polecat: he had bird flu.
Europe has been ravaged for a year and three months by the worst and most “devastating” avian flu outbreak ever, according to research by the European Food Authority EFSA and the European Center for Disease Prevention and Control (ECDC) published at the end of December.
Initially, the virus was mainly limited to wild birds (swans, geese and ducks) and poultry farms. But that is no longer the case. Foxes, polecats, otters, seals and raccoons also get the virus and – in very rare cases – people in Europe, for example in Spain, are also infected, according to the study.
Vosjes
Two months ago, an infected fox and an infected polecat were spotted in Gelderland and Friesland, according to the Dutch Wilflife Health Center in Utrecht, where dead birds are reported and investigated. Earlier that year, the virus was also found in foxes in Groningen, who probably contracted it because they ate wild waterfowl.
Such a variant will not quickly spread to humans in the Netherlands, according to Wageningen University, although the chance of this occurring will increase if the virus mutates more often. Bird flu is “usually mild” in humans, according to the National Institute for Public Health and the Environment, “but sometimes it can be serious”. The RIVM does not explain what this serious course of events means. According to the Ministry of Health, Welfare and Sport, there have been no “human cases” of bird flu in the Netherlands so far.
How is the spread of the bird flu virus in the Netherlands? In fact, the virus has never completely disappeared in recent years. The avian flu, usually introduced into the Netherlands by wild birds and transmitted via feces or feathers, was still found in wild birds in Groningen and Utrecht in the summer of 2021. A few months later, in October, a chicken farmer in Zeewolde was screwed: tens of thousands of chickens were culled. In the following weeks, poultry farmers in North Holland and Friesland were attacked by the virus.
Since then, bird flu has been around constantly, one month more intense than the other. More than a hundred bird flu outbreaks have been detected since ‘Zeewolde’, according to the Dutch Food and Consumer Product Safety Authority. And in that period, more than six million birds were culled, of which 1 million preventively. That is ten times as many as in the period 2020-21, but is dwarfed by 2003 when 30 million chickens, a third of the poultry population at the time, were culled.
In February it will become clear how effective the vaccines that are currently being developed are
After the contamination in Zeewolde, the Ministry of Agriculture introduced a national penning obligation, which prohibits commercial poultry farms from letting their animals outside, in order to reduce the chance of becoming infected through the faeces or feathers of wild birds. In the summer of 2022, the confinement obligation was partly withdrawn. But when the number of infected birds rose again rapidly in October, Minister of Agriculture Piet Adema (ChristenUnie) reintroduced the confinement obligation. In addition, the minister of agriculture has set up a working group, which, together with the Ministry of Health, must ensure that the culling of the dead birds goes smoothly.
Shortage of drivers
It had to. Because due to the war in Ukraine, gas prices suddenly rose enormously and there was a threat of a shortage of carbon dioxide, with which infected chickens are gassed in their stables. That problem seems to have been resolved now.
Read also: Chickens have still not received a flu shot
There is, however, “limited capacity” of trucks and drivers with the correct papers, who have to collect the gassed animals, Adema wrote to the House of Representatives at the end of November.
Meanwhile, in the Netherlands, as in other European countries, work is being done on a ‘step-by-step vaccination plan’. Wageningen University Research (WUR) is investigating the effect of three vaccines on behalf of the Ministry of Agriculture. In February, Minister of Agriculture Piet Adema hopes to provide more clarity about its possible application in the poultry sector.
But there are also risks associated with vaccination, says bird flu expert and WUR researcher Nancy Beerens on the website of Wageningen University. The bird flu vaccine should not only protect against the virus, says Beerens, but also against its spread. “Because if a vaccinated flock does become infected with bird flu while this is not observed due to the lack of symptoms, the virus can spread unnoticed between companies.”
A version of this article also appeared in the January 4, 2023 issue