How does adenovirus infect chickens?

Dr. Majid Hamid Al-Sayegh / Australia

Avian adenovirus type 4 (FAdV-4) is a serious viral pathogen in poultry. It is known for causing hemolytic hepatitis syndrome with pericardial ascites (HHS), which is often severe and fatal. The importance of this virus has increased in recent years due to its rapid spread and high mortality rates, along with weak preventive measures in many developing countries, particularly in Iraq, where biosecurity is weak and a suitable vaccine is lacking.

As illustrated in the image, the mechanism by which the virus infects the chicken body is explained. At the molecular level, the virus consists of several structural proteins, each with a specific role in infection and immune response. The hexon protein represents the largest part of the viral envelope and carries antigenic determinants that stimulate the immune system to produce neutralizing antibodies. The penton base has a toxic effect on host cells and contributes to the destruction of liver tissue. While the fiber protein acts as a “key,” binding to specific receptors on the surface of host cells, facilitating virus entry and determining the type of tissue affected and the severity of the infection.

After the virus enters the bird’s body, it primarily targets the liver, where it infects hepatocytes known as LMH cells. Recent research indicates that the virus exploits host cell proteins, such as CCT7, a component of the T-complex, to help it efficiently fold and assemble viral proteins within the cell.