Avipoxvirus

Avipoxvirus

Avipoxvirus is a genus of viruses in the family Poxviridae, subfamily Chordopoxvirinae. These viruses primarily infect birds, causing a disease known as avian pox. Avian pox is characterized by the formation of proliferative lesions on the skin and diphtheritic lesions in the upper respiratory tract and oral cavity.

Structure

Avipoxviruses are large, complex viruses with a double-stranded DNA genome. The virions are brick-shaped and measure approximately 200-300 nm in diameter. The genome of avipoxviruses is linear and can range from 250 to 300 kilobase pairs in length. The virus is enveloped, which means it has a lipid membrane surrounding its protein capsid.

Transmission

Avipoxvirus is transmitted primarily through direct contact with infected birds or through mechanical vectors such as mosquitoes and other biting insects. The virus can also be spread via contaminated surfaces, such as feeders and perches, where infected birds have left virus particles.

Hosts

Avipoxvirus infects a wide range of bird species, including domestic poultry such as chickens and turkeys, as well as wild birds like canaries, pigeons, and raptors. Different strains of avipoxvirus tend to be host-specific, although cross-species infections can occur.

Clinical Signs

Infected birds may exhibit a variety of clinical signs depending on the strain of the virus and the species of bird. Common signs include:

• Cutaneous form: Wart-like lesions on unfeathered skin areas such as the legs, feet, and around the eyes and beak.
• Diphtheritic form: Lesions in the mouth, throat, and respiratory tract, which can lead to difficulty breathing and swallowing.
• Systemic form: More severe infections can lead to generalized illness, affecting internal organs and leading to death.

Diagnosis

Diagnosis of avipoxvirus infection is typically based on clinical signs and the presence of characteristic lesions. Laboratory confirmation can be achieved through histopathology, virus isolation, or molecular techniques such as PCR to detect viral DNA.

Prevention and Control

Preventive measures include vaccination, which is available for some species, and management practices to reduce exposure to vectors and contaminated environments. Good biosecurity practices are essential in preventing the spread of the virus in poultry operations.

Also see

• Poxviridae
• Chordopoxvirinae
• Avian diseases
• Viral infections in birds