Influenza A virus antigen negative?

In daily life, influenza A virus is a common influenza virus. Influenza A virus is the most likely to mutate. Influenza A virus is called "bird flu". Bird flu is an acute infectious disease caused by avian influenza virus. It can also infect humans. The symptoms after infection are mainly high fever, cough, runny nose, myalgia, etc., most of which are accompanied by severe pneumonia. If the test result of influenza A virus antigen is negative, it means that you are not infected with influenza A virus, and everyone can rest assured.

Influenza viruses are divided into three types: A, B, and C. Type A influenza virus is most likely to mutate. An influenza pandemic is caused by the emergence of new subtypes of influenza A virus or the reappearance of old subtypes. The surface antigens of influenza A viruses often undergo small mutations, which are called "drift". Figuratively speaking, "drift" means that the virus disguises itself through small changes to avoid recognition by the human immune system. The result of the "drift and mutation" of the type A virus is that the strain that causes influenza may be different every year, and people need to be re-vaccinated with influenza vaccine every year for prevention. A "shift" is when the influenza A virus mutates, resulting in the emergence of a new "subtype" of the virus. Because the human body has almost no antibodies to resist this new virus, the result of "mutation" often leads to a global outbreak of influenza. Influenza viruses usually invade the human body by combining a certain part of the viral protein with a specific protein in the human body. Through such combination, the influenza virus can suppress the human body's own natural defense system against viral infection, paving the way for the virus to effectively replicate in the human body.

Influenza viruses are divided into three types: A, B and C. Influenza A virus is divided into many subtypes based on the differences in H and N antigens. H can be divided into 17 subtypes (H1~H17) and N has 10 subtypes (N1~N10). Among them, only H1N1, H2N2, and H3N2 mainly infect humans, while the natural hosts of many other subtypes are various birds and animals. Among them, the H5, H7 and H9 subtypes are the most harmful to poultry. Generally, avian influenza viruses do not infect animals other than birds and pigs.

However, in 1997, Hong Kong reported its first 18 cases of H5N1 human avian influenza infection, including 6 deaths, which attracted widespread attention from the world. Since 1997, there have been several incidents of avian influenza virus infecting humans in the world. Once highly pathogenic avian influenza viruses such as H5N1, H7N7, H7N9, and H9N2 mutate and become capable of transmission from person to person, they will cause an epidemic of avian influenza in humans, indicating that avian influenza viruses have become a great potential threat to humans.