January 19, 2023 at 9:30 a.m.
Up to date on January 20, 2023 at 09:45
Studying time: 5 minutes
The chook flu epidemic is progressing. For a yr, bulletins of outbreaks of an infection have been raining down. The French, English and Hungarian farms are decimated. Wild birds too. The well being authorities perform huge culling of contaminated farms, in useless. Because the epidemic lingers, is the human subsequent on the record ? This risk is feared by consultants and well being authorities: the extra intense the circulation of the virus, the larger the chance of mutations. And all that is lacking is a brief — however important — set of mutations to ignite the hearth.
In December, Ecuador introduced the looks of a primary outbreak on its land. A month later, the Ecuadorian Ministry of Well being reported a case of human contamination. A 9-year-old lady developed signs of the illness within the province of Bolivar, within the coronary heart of the Andes. The state of affairs shouldn’t be new: in 2021 and 2022, a minimum of 4 different instances have been recognized in the UK, america and Spain.
Since 2003, almost 865 people have been contaminated with avian flu, in twenty-one nations (primarily Africa and Asia), stories the Guardian. And the virus, which appeared in 1997 in poultry farms in Hong Kong in China, appears violent on people: 456 have died. Nevertheless, no transmission between people has been reported: all contaminated individuals lived in shut proximity to sick poultry farms, and have been straight contaminated by the animal.
A sequence of essential modifications
The state of affairs may change. Consultants concern that the document waves of avian flu – and particularly the multiplication of the virus inside farms and its unfold to different species – will favor the looks of a type that’s each pathogenic for people, but additionally appropriate for human-to-human transmission. “ If this transmission appeared, the state of affairs would turn into dramatic », explains Muriel Vayssier-Taussat, director of the animal well being division on the Nationwide Analysis Institute for Agriculture, Meals and the Setting (Inrae). Over the past September-December interval, the European Meals Security Authority (EFSA) recorded a rise in contaminated farms of 35 % in comparison with final yr.
- Thus far, no human-to-human transmission of avian flu has been reported. Pixabay/CC/Ehrecke
In actual fact, the chook flu virus has already contaminated a minimum of sixty-three different species, together with lynxes, seals or bears, provides the Guardian. And the proximity between sure kinds of farms may velocity issues up. “ The swine flu virus can, just like the avian flu, be unintentionally transmitted to peopleexplains the researcher. The proximity between pig and poultry farms and the assembly of those two viruses may promote the emergence of latest viruses. These may infect people much more successfully and trigger epidemics. »
The authorities are making ready
It’s nonetheless within the script stage. The virus is usually thought of low danger for people, says François Moutou, veterinarian and epidemiologist, specialist within the illness: “ The various kinds of chook flu [H5, H7 et H9, l’actuelle étant H5N1] don’t trigger epidemics in people. Instances exist [à la suite d’une mutation ou une faiblesse d’un patient]however general these viruses fail to connect themselves to the human respiratory tree, which permits us to flee a majority of these viruses. » However the extra we enhance the probabilities of viral multiplication, the extra we enhance the probabilities of variations within the virus and of contact with people.
And the authorities understand it. The World Well being Group warns that “ the range of avian influenza viruses and different zoonotic influenza viruses which have prompted infections in people is alarming and there’s a have to strengthen surveillance of animal and human populations, intently examine every case of an infection in people and set up a planning based mostly on pandemic danger ».
Avian flu is candidate for the subsequent pandemic »
Final October, Public Well being France reviewed “ the conduct to observe for the surveillance and investigation of instances of human influenza on account of an influenza virus of avian origin ». Thus, within the occasion of suspicion, the well being authorities will perform the take a look at, and within the occasion of positivity, the examination of contact instances in addition to of individuals uncovered to the identical outbreak. The target: to establish contaminated individuals, but additionally the potential look of human-to-human transmission.
In the interim, no French individual has been affected and surveillance is going down on the stage of contaminated farms. Authorities are sequencing avian flu strains to confirm that they haven’t mutated. So long as the virus circulates, the chance will persist. For Muriel Vayssier-Taussat, avian flu is “ candidate for the subsequent pandemic ». For her, you will need to “ restrict the circulation of the virus », to cut back the chance of the looks of a deleterious mutation. It focuses particularly on vaccination. However beware, it might not be accepted by enterprise companions, warns François Moutou. He believes that we’ve reached the tip of the intensive mannequin. “ This yr 2022 should push breeders and the administration to consider new options. »
In an opinion issued in June, ANSES recommends drastically lowering the density of waterfowl farms to cut back the depth of the epidemic. It additionally recommends lowering the density of farms on a regional scale, along with biocontrol measures. In all instances, “ no measure will suffice by itself, they have to be mixed »provides François Moutou.