Avipoxvirus: Fowlpox virus (FWPV), Canarypox virus (CNPV) or other birds Poxvirus - Molecular diagnosis (PCR); Identification of strain / species (PCR and sequencing)

The Poxiviridae (poxvirus) virus family includes large, complex structure with double - stranded DNA (dsDNA) from 230 to> 300 kbp. Chordopoxvirinae and Entomopoxvirinae: This family includes two subfamilies. The first includes infecting vertebrate species and the second species that infect invertebrates. The Chordopoxvirinae subfamily the various genres that most affect mammals (orthopoxvirus, Parapoxvirus, Capripoxvirus, Leporipoxvirus, Suipoxvirus, Yatapoxvirus and Molluscipoxvirus) are included. Avipoxvirus gender is a genus of the subfamily Chordopoxvirinae whose species infect birds.

The classification of species of Avipoxvirus is complex because it is based on genomic sometimes difficult to discern differences due to the high chance of recombination during replication when two different viruses penetrate the same host, knowing little about the host specificity ..

The prototype of Avipoxvirus is the chicken pox virus (fowlpox virus -FWPV-). This species, fowlpox virus mainly affects birds Galliformes (gallinaceous: roosters, turkeys, partridges, pheasants, quail, ...), but not exclusively. The same applies to other viruses that have been characterized as Caranypox virus (CNPV) (preferably affects birds passiformes -pájaros-), Turkeypox virus (TKPV) (affects turkeys), Pigeonpox virus (PGPV) (affects pigeons) or Quailpox virus (QUPV) (affects quail Coturnix coturnix). Among these species, for some strains would rather than species, there are antigenic similarities but also some genetic difference that differentiate them from each other. Of these, fowlpox virus (FWPV) would be the prototype that would affect birds Galliformes (gallinaceous) and canarypox (CNPV) virus would be the prototype that would affect the pasiformes birds (birds).

Avipoxvirus infections

All Avipoxvirus may result primarily two main types of infection, skin and mucosa (difteriformes) as the gateway the virus. Sometimes can cause similar symptoms to pneumonia (pneumonia-like).

Cutaneous infections occur when the virus penetrates through a skin trauma or an arthropod bite. These infections affect featherless areas, such as around the eyes and nasal nares, around the peak, crest, fingers, legs or leg itself. They look a proliferative nodule that hardens to become scabby. Sometimes nodular lesions ulcerate or enlarged preventing vision, power and mobility. Birds that survive infection may have defects fingers, legs and beak.

The difteriformes infections, also called wet, less frequent skin lesions, mucous affect the digestive tract or upper respiratory tract. These infections are generated by inhalation and are preferably encentran oral mucosa, pharynx and sometimes to the trachea. Usually have higher overall mortality rate due to occlusion of the oropharynx that hinders breathing and swallowing.

Diagnosis of infections Avipoxvirus

The diagnosis of infections Avipoxvirus, like other Poxviridae, was made by histological microscopic view, by electron microscopy examination by isolation chorioallantoic membrane chick embryo and detecting antibodies.

However, today, molecular methods (PCR) have simplified the diagnostic when have known Avipoxvirus shared by all genomic sequences. These sequences encoding regions of core proteins (core) as the P4b, a conserved region of 75.2 kDa, which is usually common to 64.2% among species / strains. The differences in these regions are based on the presence of indels (insertions or deletions of 18 to 52 nucleotides differentiate strains / species).

Tests in IVAMI:

  • Molecular detection of each species / strains of Avipoxvirus, by genomic PCR amplification and their typing by nucleic acid sequencing.

Type of samples required

  • Biopsy or scrapings of the lesions in sterile container.  

Preservation and shipment of sample:

 

  • Refrigerated (preferred) for less than 2 days.
  • Frozen: over 2 days.  

Delivery time results

  • Test molecular detection (PCR): 24 to 48 hours on weekdays.
  • Test molecular detection (PCR) and identification of strain / species (sequencing): 5 to 7 days.  

Cost of RT-PCR test: