facilitates its transition to humans

Over the past few months, the United States has been faced with a public health crisis: an epidemic of avian influenza A(H5N1), which has particularly affected livestock but has also spread to free-ranging birds and humans.

New things. This week the CDC (Centers for Disease Control and Prevention) The United States has published a new report on the status of the avian influenza A(H5N1) epidemic affecting the country. In this update, the monitoring team announced two new infections in humans and one case that has attracted the attention of experts: an infection in pigs.

The latter was discovered in a pig on a small farm in northwestern Oregon. The case was identified on October 30 and is the first infection in pigs in this epidemic and in the United States as a whole.

The livestock farm has been quarantined by the United States Department of Agriculture (USDA). The birds in it were killed, and the remaining animals are being monitored, the report said. Reuters.

Small risk. The fact that the case was identified on a small farm and used for non-commercial purposes has positive consequences, the authorities explain. On the one hand, because this reduces the likelihood of infection, on the other hand, because the case does not affect the food market.

More than a simple infection. However, there are also reasons for caution in this new case. As stated in the article for Talk By K. Raina McIntyre and Hayley Stone, two experts from the University of New South Wales (UNSW), the move to pigs implies a new risk associated with the epidemic.

If this epidemic did not spread to people, then this is due to the mechanism of penetration of the influenza virus into the cells of the respiratory system. Avian influenza has a mechanism that has specifically evolved to open the cell wall in bird cells.

Once these viruses reach our respiratory system, they have a very difficult time infecting our cells. That is why infection occurs only in people who are in close contact with infected animals. However, introducing pigs into the equation could change that, McIntyre and Stone warn.

Favorable place. Since the respiratory system of pigs is more similar to ours. These animals have some cells similar to the cells of birds and ours. This means that pigs can be infected with both avian and human viruses.

This is where the problem arises: when two viruses infect the same organism, they can end up mixing their genetic material, McIntyre and Stone explain. This suggests the possibility that this co-infection will lead to the emergence of new variants that are potentially more transmissible to humans.

44 people and 440 livestock farms. Although the transition to humans has so far been limited, with 44 cases identified in humans in the United States, the virus indirectly affects humans. Through cattle.

The outbreak has affected not only more than 100 million poultry, 440 livestock farms, but also at least 10,400 birds in the wild. The scale of the outbreak affects not only the meat industry, but also the dairy industry.

Influenza A(H5N1). The first cases of the disease in the United States were identified in March of this year, but the outbreak of avian influenza A(H5N1) has been active in the world since 2022. The outbreak is caused by one of the most important subtypes of avian influenza: A(H5N1) caused, according to WHO, at least 904 cases of human infection, of which 464 cases resulted in death. The outbreak in the United States has led to a decline in deaths associated with the virus.

In Hatak |

Image | Christine Snippe / Cottonbro studio