1Central University Laboratory Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, India
2Vaccine Research Centre - Viral Vaccines, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, India
3Post Graduate Research Institute in Animal Sciences, Tamil Nadu Veterinary and Animal Sciences University, Kattupakkam, India
*Corresponding author: S Jaisree; E -mail: jaisree.s@tanuvas.ac.in
Online published on 17 October, 2020.
This study reports the histological lesions in archived formalin fixed piglet tissues from a herd subclinically infected with PCV2 that progressed to showing PCV2 associated systemic disease and later experienced a major fulminating episode of PCV2 induced reproductive failure characterized with abortions, mummified fetuses, still births and neonatal mortality. Lymphoid cell depletion in one or two lymph nodes were observed in subclinical infection. In PCV2 associated systemic disease multiple lymph nodes revealed variable degree of lymphoid cell depletion and necrosis with multinucleate giant cells, syncytia formation and intracytoplasmic inclusions. Histopathological changes in other organs included multifocal, severe lymphoid depletion and extensive necrosis in spleen; multifocal coagulative necrosis in Peyer’s patches; diffuse lymphohistiocytic interstitial pneumonia in lungs; multifocal necrotizing hepatitis in liver. A progressive shift in lesion type was noticed when the infection progressed from subclinical infection to PCV2 associated systemic disease. PCR assay performed with DNA extracted from formalin fixed tissues showed specific amplification product of 620 base pairs, confirming the presence of PCV2 ORF2 genome in the tissues
HIGHLIGHTS
• This paper describes subclinical and clinical PCV2 infection among piglets.
• Moderate diffuse lymphoid depletion in lymphoid tissues were observed in subclinical infection
• Severe lymphoid depletion with viral inclusions and syncytia were characteristic of clinical PCV2 infection.
PCV2, Histopatholgy, Clinical and subclinical infection, PCR from archival tissue
