Fowl Pox outbreak in a layer farm: update data on phylogenetic analysis in Iran, 2018

Document Type: Short Communication


1 Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

2 Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

3 Department of Clinical Sciences, Faculty of Veterinary Medicine, Islamic Azad University, Tehran, Iran

4 Department of Clinical Sciences, Faculty of Veterinary Medicine, Islamic Azad University, Karaj Branch, Alborz, Iran


Fowl pox is an economically significant viral disease in poultry which described in two forms of clinical signs including cutaneous and diphtheritic lesions. Fowl pox can have several adverse effects on flock performance such as decreasing the egg production and growth and increasing the mortality. In winter 2018, an infection suspected to Fowl pox was reported from a Hyline W36 layer farm from Isfahan province. The birds were 38 weeks of age and showed obvious diphtheritic signs in mucous membranes with increases in mortality and decreased egg production. Twenty samples from diphtheritic lesions (Trachea and Esophagus) of infected birds were collected. Polymerase Chain Reaction was used to amplify a 578 bp fragment of the poxvirus 4b core protein gene. Phylogenetic relationships of avian poxviruses are usually analyzed using the DNA sequences of the 4b core protein coding protein with molecular weights of 75.2 kDa. For virus detection, specific gene element, and sequencing was performed for one isolate as representative. The result of, nucleotide sequence showed that this isolate (FP\UT-POX-2018) has an identity of 99.53% with the previous Iranian fowl pox isolate (FP\GHPCRLAB.3) sequences in the Gen Bank. Also, there was 100 % similarity between current isolate nucleotide sequence and FP/NobilisVarioleW and FP/FPV-VR250. The derived phylogenetic tree showed that these isolates were clustered in A1 subclades. Hence, Iranian isolates of fowlpox virus have remained in the same subclade of phylogenetic classification (subclade A1), and they show high genomic similarity with previous isolates of Iran. It is necessary that veterinarians and farmers don’t underestimate fowlpox and know the importance of vaccination against this disease like any other disease care.