These are the risks of its greatest pandemic potential.

A new study has recently shown that bird flu H5N1 It can be transmitted between mammals through contaminated cow’s milk and reach the mammary glands, increasing its pandemic potential. While the World Health Organization (WHO) expressed “concern” about the disease in May, the European Centre for Disease Prevention and Control (ECDC) has now recommended strengthening surveillance. These are the risks of your greatest pandemic potential..

It all started this spring, when the first outbreak of bird flu hit the U.S. dairy cattle. Since then, the disease has spread through herds and been seen in other mammals. In fact, four cases have already been detected in humans in the U.S. — all workers. That’s why he was warned “higher risk” to public healthAccording to a study by Yoshihiro Kawaoka (University of Wisconsin-Madison) published this week in Nature.

Avian influenza in cattle: a new scenario

The study showed that the virus is transmitted to mice through the milk of cows infected with the flu, as well as through intranasal contact with mice and ferrets. The virus enters the mammary glands of infected animals, and has been observed to be transmitted from infected suckling mice to their offspring. This means that the disease is spreading systematically and, unlike other strains, the current one has characteristics that favor the infection of mammals, including humans. Aitor Nogales González, senior researcher at the CSIC Animal Health Research Center, explained to Efe that “the risk to the population is considered low,” but “the situation may change in the future and we must remain alert“We must remember that in the recent flu pandemics, the main cause was bird flu,” he concluded.

Elisa Pérez Ramírez, from the same Spanish research centre, also told Efe that the results of the study are important because of their impact on animal health and public health in the context of a very current health warning. The virus has caused massive deaths of poultry across the planet since the end of 2020, as well as hundreds of thousands of wild birds. “We are experiencing the largest bird flu epidemic in history,” he recalled, insisting that the virus has gradually acquired greater transmissibility in mammals – the Spanish state in 2023 raised international alarm due to an outbreak on a mink farm. But it has never been detected in cattle, so the scenario is “completely new, with many questions“.

Symptoms of bird flu in humans

As we have already reported, this week the ECDC has spoken out and recommended increased surveillance. Although it should be noted that the circulation of bird flu among birds in the EU is still low, the agency recalled the situation in the US (with infection of livestock and humans). “As we closely monitor the current situation with bird flu both in the EU and in the rest of the world, there is reason to be more aware, but not more concerned. (…) The threat to human health cannot be underestimated and it is important that we remain vigilant and proactive in our joint collaboration,” said ECDC Director Pamela Rendi-Wagner.

Given the possibility of infection, we must remember that Symptoms of bird flu in humans are similar to those of traditional flu.: high fever (39–40 °C), muscle aches, dry cough, headache, sore throat, general malaise, runny nose, nasal congestion, fatigue and diarrhea. Most often, symptoms appear two to eight days after infection, although this depends on the virus: two to five days in the case of H5N1, but it can take up to 17 days.