Penguins, polar bears, dairy cows. And now also a human patient, the second in America. Avian influenza has continued to circulate for two decades across the planet, in a tour de force that risks making the H5N1 virus increasingly capable of effectively infecting mammals, and perhaps even humans. For now, the dangers for our species are minimal, as the American and European health authorities remind us, but if a highly pathogenic strain capable of transmitting between humans were to emerge in the future, the risks of a new pandemic would become more than real. We talked about it with Matteo Bassetti, Full Professor of Infectious Diseases at the University of Genoa and Director of the specialization school in Infectious Diseases at the University of Genoa.
Professor Bassetti, what virus are we talking about?
The one that recently infected the Texan patient is a highly pathogenic influenza A virus of the H5N1 subtype. It is the lineage that has been circulating since the late 1990s, and has infected millions of chickens, pigeons, ducks, and has been found in polar bears in Alaska and penguins at the South Pole. It has recently caused outbreaks in several animal farms. American cattle, and this means that it is becoming better at infecting mammals: every time it makes a move into a new species it accumulates mutations and the chances that new, increasingly dangerous strains will be selected increase. At the moment only direct infections from animals have been recorded in humans, as in the Texan case where we are probably talking about a person who worked in close contact with infected cows. But the arrival of a mutated strain capable of transmitting from human to human is possible, and indeed increasingly probable with each new contagion. And if that happened we would risk a new pandemic, perhaps worse than the one we experienced with Covid.
Why is bird flu so scary?
H5N1 is a virus that to date when it has affected humans has proved to be extremely serious, with a mortality rate of up to 50%. It's probably not the percentage we would really see during a pandemic, but in any case if we think that Covid in the worst moments has never exceeded 3% mortality, it is easy to understand that it is a dangerous virus. There is obviously no need for alarmism, also because the risks for humans are currently considered very low, but it is certainly important to keep our attention high. When the WHO talks about disease Indeed, he probably has the avian flu virus in mind: it has been considered a threat for 30 years, and it was precisely from the first avian flu epidemics at the beginning of 2000 that we started talking about pandemic plans. Now what we need to do is keep these pandemic plans updated, and not act like an ostrich like in the past.
The government has updated the pandemic plan, not without controversy.
Yes, Vaia did a great job updating it (here is the latest public draft), but have you heard anything about it since November? It is important that it does not remain there, but that it circulates, that everything is ready to actually apply it as soon as it is needed. Here we risk being left at a standstill, amidst controversies over lockdowns, vaccines, and so on, while the rest of the world is working to prevent the next pandemic.
What does being ready mean in this case?
It means knowing how many beds we have in the event of a pandemic, and which ones. How many intensive therapies. How many masks for healthcare workers, and where to get them in case of need for the population. Have supplies of medicines and vaccines. What should be done if the disease arrives in an Italian farm? How are quarantines done if necessary? We must know how to answer these questions, everything must be written on the pandemic plan and we must be ready to put it into practice. Otherwise we risk finding ourselves in chaos again, like the 30 dpcm that were needed to deal with the last pandemic.
Bird flu pandemic could be '100 times worse' than Covid
If the virus were to mutate enough to infect humans it could spread rapidly. Symptoms of bird flu are similar to those of other flus, including cough, muscle aches and fever. Some people may not develop noticeable symptoms, but others can develop severe, life-threatening pneumonia. According to the World Health Organization, about 52% of people who have contracted H5N1 since 2003 have died. For comparison, COVID currently kills less than 0.1% of those infected, although at the start of the pandemic the mortality rate was around 20%.