The H5N1 strain of bird flu It was first discovered in 1996 on a goose farm in China. Since then, the virus has spread around the world and become more dangerous, affecting at least 485 species of birds and 48 species of mammals. Since October 2021, more than 280 million birds have died from H5N1.
According to data from the World Health Organization (WHO), between 2003 and November 2023, 880 human cases of bird flu in 23 countrieswith a total of 460 deaths. The current bird flu outbreak began in 2024 and has spread to farms in USA.
This week we learned that a scientific study, published in Natureshowed that Milking is the source of transmission of avian flu in the outbreak that has affected North American cattle since the beginning of this year, which belongs to the H5N1 strain of the virus. The cows have been infected on at least 231 farms from 14 states.
But, as we see, the virus also affects human beings. Four livestock farm workers have also been infected and the US Centers for Disease Control (CDC) have first human case recently reportedwhich, in principle, was not exposed to any sick animals.
Europe has to prepare
A team from the Department of Pathobiology and Medical Diagnostics at the Kansas College of Veterinarians has seen that the virus resides mainly in the mammary glands of cows milkmaids. For this reason, “transmission routes not related to milk seem less relevant,” although they suggest that the modes of transmission in adult cows still need to be evaluated in more detail.
In June, the US Food and Drug Administration noted that 20% of US milk supply shows signs of H5N1 virus. In Europe, cow milking procedures are not very different. So is there the same risk? You have to put yourself in the worst.
The authors of the study carried out on American farms tried infecting their experimental cows with influenza directly taken from European birds and the course of the disease was just as bad. Therefore they maintain that Europe has to prepare.
turning point
Thomas Peacock, of the UK Pirbright Instituteassures that “containment strategies are not working.” In a article published in Naturethe expert assures that the possibility of the highly pathogenic strain of bird flu establishing itself permanently in Europe and America is a “turning point”. At the moment, the H5N1 virus has also spread through fur farms in Europe.
Peacock gives the alert because in its opinion the virus has become virulent and that has happened after mild avian flu combined with another type H5N8. According to this specialist in the spread of viruses from animals to humans, H5N1 could be transmitting undetected in the United States due to “months of lost data” that have left researchers, veterinarians and authorities in the dark.
According to Peacock and his colleagues at the Pirbright Institute, new control measures, including vaccination. Some poultry vaccines already exist, but they do not prevent infection. If the virus begins to spread among humans, new vaccines could be needed “on a large scale.”
Very low risk for the population
Until now, until the new study on North American cows, there was no alarm in Europe or Spain. A recent report from Coordination Center for Health Alerts and Emergencies (CCAES), dependent on the Ministry of Health, analyzed the recorded human cases and maintained their classification as very low risk for the population Spanish.
Likewise, the European Center for Disease Prevention and Control (ECDC) until now considered the risk of infection from the avian flu virus to be low for the general population and moderate for those who work with infected birds or are exposed to them. However, after the study carried out in the USA, the European Food Safety Authority (EFSA) warns of the need to increase surveillance, especially in mixed farms.
Worrying finding, new measures
“This finding is worrying because it could indicate that avian flu has more ways of spreading than we thought… If the feasibility of transmission through milking is confirmed in Europe, we will have to quickly adapt our containment strategies“, declared a representative of the EFSA.
Farmers may then need to make new investments. The European Milk Producers Federation (EDA) has asked the European Parliament financial support to implement new detection technologies of viruses on farms. “The health of our workers and the integrity of our farms are at stake,” says an EDA spokesperson.
In July, the report on bird flu prepared by EFSA, ECDC and the EU reference laboratory showed that Europe had recorded the lowest number of bird flu cases highly pathogenic in poultry and wild birds since 2019/2020. The document was based on data reported between March 16 and June 14, 2024. The report further noted that the risk to the general public remained low.
European contract for the purchase of vaccines
At the moment, the European Union is arming itself against the virus due to the possibility of growth in infections. In June, the European Commission announced a contract for the initial purchase of 665,000 doses of the Seqirus vaccine against H5N1 avian flu. Then, depending on the evolution of the crisis, one could buy up to 40 million doses.
The vaccine is the only preventive remedy against zoonotic avian influenza currently authorized in the EU. It would be distributed to most exposed population to possible infections, such as poultry farm workers and veterinarians.
