Type C avian retroviruses, also known as avian leukosis viruses, are a group of retroviruses that primarily infect birds. They belong to the family Retroviridae and the subfamily Orthoretrovirinae. These viruses are enveloped and possess a single-stranded RNA genome, which is reverse transcribed into DNA upon entering the host cell. They are classified as type C because of their characteristic viral particles with dense cores.
Type C avian retroviruses can cause different forms of diseases in birds, including lymphoid leukosis, erythroblastosis, myeloid leukosis, myelocytomatosis, and sarcomas. These diseases have significant economic implications in the poultry industry due to decreased productivity and mortality.
These retroviruses are commonly transmitted vertically from infected hens to their offspring through the egg, but horizontal transmission can also occur between birds through respiratory secretions, feather follicles, and contaminated surfaces. They primarily target the lymphoid tissues and bone marrow, leading to the development of tumors and disruption of normal immune function.
Prevention and control strategies for type C avian retroviruses involve strict biosecurity measures, such as preventing introduction of infected birds, proper sanitation, and vaccination programs. Live attenuated and recombinant vaccines have been developed to provide protection against these retroviruses, reducing the incidences of the associated diseases.
In summary, type C avian retroviruses are a group of enveloped retroviruses that infect birds, causing various diseases with significant economic consequences in the poultry industry. They are transmitted vertically and horizontally and primarily target lymphoid tissues and bone marrow. Strict biosecurity measures and vaccination programs are crucial for their prevention and control.
