The co-infection and genetic characterization of porcine circovirus type 2 and 3 in pigs having the signs of reproductive and respiratory disorders

Abstract

The objective of this study was to determine the co-infection and genetic characterizations of porcine circovirus (PCV) type 2 and 3 in pigs having the signs of reproductive and respiratory disorders. Tissue, blood, and body fluids samples were collected in the pigs showing clinical signs of the disease from 25 different farms in many provinces/cities. The studied results showed that the infection rate of pig with
PCV2 and PCV3 was 51.52% and 44%, respectively; while the co-infection rate of pig with PCV2 and PCV3 was 16 % according to the surveyed farms. PCV3 was detected mainly in cases of reproductive disorders in the sows and PCV2 was in cases of respiratory disorders in the post-weaning piglets
(P<0.05). The prevalence of PCV2 and PCV3 infection in the tissue samples was 58.14% and 27.78%, respectively, with P<0.05. Concurrent, PCV3 infection rate was highest presenting in the sample of miscarriage/stillbirth (43.33%), and PCV2 was detected with the highest rate in tissue samples of the respiratory failure cases (58.14%). PCV2d was the predominant genotype (83.33%) in the respiratory
disorders, and the identity of the current strains ranged from 93.38% to 100%. The complete PCV3 genome in the reproductive disorder cases belonged to the PCV3b group. The studied result provides scientific information on the prevalence and association of PCV3 2b in reproductive disorders in sows.