Definition of Severe Systemic PCV2 Infection

Severe systemic PCV2 infection (Postweaning Multisystemic Wasting Syndrom; PMWS) is considered a multifactorial disease in pigs, in which a necessary factor is the presence of PCV2. Since PCV2 is ubiquitous in the pig population and infection doesn’t equate to disease, a definition for PMWS was proposed (Sorden, 2000). Based on this definition, a diagnosis of PMWS requires (1) the presence of clinical signs such as wasting, weight loss, and respiratory disease, (2) the presence of the hallmark PCV2-associated microscopic lesions (lymphoid depletion and/or histiocytic replacement of follicles in lymphoid tissues or both), and (3) PCV-antigen or nucleic acids associated with the microscopic lesions as determined by IHC or ISH (Sorden, 2000).

 

Reference:

Sorden SD: Update on porcine circovirus and postweaning multisystemic wasting syndrome (PMWS). Swine Health Prod. 8:133-136, 2000