News about bird flu keeps happening in the United States. The latest was the detection of the virus in a sample of raw milk sold to the public in California. A new case of bird flu in humans has also been confirmed in the same state. This time it is about first infection of a minor which was recorded in the country, and at the moment its origin is unknown.
With this, there are already 55 human infections of bird flu in the United States. Most of them maintained a close contact with infected animalsmore specifically, with dairy cow farms. Since the first case was confirmed on March 24, at least 616 herds have been affected. Another species of particular concern is poultry. In this case, a total of 1,229 outbreaks were reported.
The volume of infections in Spain is still far from that of the United States. However, the Galician Ministry of the Environment confirmed last week three new outbreaks of avian flu in wild birds. To prevent its spread, some European governments have already taken measures in this regard. One of the last to do so was Belgium, which ordered poultry farmers to confine their birds, although no recent cases of bird flu have been detected in the country.
The Belgian government argues that this decision follows the recommendations of the European Food Safety Authority (EFSA). This is not the first warning issued from Europe. Midway through this year, the European Center for Disease Prevention and Control (ECDC) recommended increased surveillance for new cases of bird flu.
“It could end up here.”
Looking at the current panorama in North America, the question that may arise is why the same thing is not happening on the other side of the Atlantic. “In the United States, there are no special conditions for this to happen, i.e. this could happen in Europe at some point“, underlines EL ESPAÑOL Gustavo del Realresearcher at the National Institute of Agrifood Research and Technology (INIA-CSIC).
For the veterinary virologist from the Animal Health Research Center (CISA) of the CSIC, Elisa Pérez-Ramirez“the important thing now is to be closely monitoring everything that happens in the United States“, since he does not exclude that “this could end up happening here”. To avoid this, he believes that it would be necessary to “considerably improve surveillance”. Especially in cattle, because this is “where there is has the greatest risk.”
Both agree that the current livestock situation is “very worrying”. But what worries them the most, because of the pandemic potential it could have, are the three avian flu infections in humans for which there is no known close contact with infected animals: the patient of the Missouri, the case detected in Canada and that of a minor in the United States. “We are worried because this could be the first sign that there is a silent transmission between people,” warns Pérez-Ramírez.
If effective transmission between humans is confirmed, it would occur the last condition to face a pandemic scenario. As the spokesperson for the Spanish Society of Infectious Diseases and Clinical Microbiology (Seimc) points out, Luis Buzon“This ability, which I hope it does not acquire, is what is missing from a virus that already meets the other two conditions: being new to humanity and highly pathogenic at the time of infection.”
A scenario of uncertainty
In view of a pandemic caused by avian fluthe first actions to take, in addition to “preparing hospitals”, would be to “sequence the virus, mass produce vaccines and distribute them globally”. Even if today designing a vaccine against the circulating virus would be, as Buzón believes, “utopian” because its evolution could make it ineffective in the short term.
Vaccination is, according to Pérez-Ramírez, an important tool to maintain control, at least in the case of animals. In France, following the epidemics that occurred between 2021 and 2022, they decided to vaccinate all poultry against the virus, obtaining a positive result. Nevertheless, “It wouldn’t be as simple as vaccinating“, we should also have “prevention and control systems that detect the virus early and allow effective measures to be taken.”
To reduce the pandemic threat, the key is to try to keep domestic animals away from wild birds, the reservoir of the virus. In humans, it is also important to avoid contact. The more you are exposed to the virus, the more options there are for the virus to adapt and the necessary mutations are found to be stable and transmitted efficiently between people.
In this case, experts recognize that there would be a large number of vaccine prototypes, in addition to good diagnostic systems. “We’re obviously not starting from scratch,” Pérez-Ramírez says. “But it is a complex virus, very easy to pass from one host to another. In recent years it has experienced a series of epidemiological changes never seen before. And this places us in a scenario of considerable uncertainty. »
