It had to happen and it did. In January 2022, the UK became the first country in Europe to detect a case of H5N1 flu. Since this week, Spain finished second. This is important because we are talking about a strain with a mortality rate that, according to WHO, can reach 60%. However, if we put it in context, we realize that this is excellent news.

What we know about the Spanish case. As confirmed by the National Center for Microbiology, the first positive for H5N1 avian flu in a human in the country was a worker on a farm in Guadalajara who was actually suffering from an outbreak of the virus among his birds. The worker (the only person who tested positive) never showed symptoms and was only found positive as all personnel were checked in these cases.

Rarely seen? Not much. This year Spain experienced the worst epidemic in its history. So far, the country has managed to emerge unscathed from the biggest bird flu outbreaks. However, what started with the deaths of four wild swans and a stork along the Segre river bed turned into a massive epidemic that shut down farms in half the country and killed more than 665,000 birds in a month.

And it’s not just a Spanish thing. The European Food Safety Authority described the 2021-2022 avian flu season as the largest recorded in Europe, and according to the World Organization for Animal Health, there were more cases in 2021 than the previous five years combined: 462% of cases and 150% in birds compared to 2020. more deaths

Good news. The fear of many experts is that these large outbreaks will facilitate the emergence of variants of this strain that are more contagious in humans. Something that could be a primary health concern given the mortality rate. However, in the context of the largest outbreak in history, it makes sense to have found a single case of influenza in humans (WHO has documented 864 cases in the last 20 years), confirming that this strain continues to have great difficulties in spreading. jumping from one type to another.

What can we expect? A little. As I said, human cases of H5N1 flu are nothing to worry about right now. First of all, if we talk about the general population. However, it does represent a warning about the need to maintain a proactive epidemiological surveillance capable of finding, isolating and intervening in such new realities that it is still difficult for us to imagine them.

Image | Thomas Iversen