Porcine Circovirus Type 2 (PCV2) is a viral pathogen of pigs that is involved in a variety of clinical diseases and syndromes. Many farms have a high seroprevalence and, generally, clinical disease directly associated with PCV2 is not very common. However, in the subclinical infection, the presence of PCV2 can be responsible for production losses, mostly due to growth retardation and reduced average daily weight gain.
In the acute or systemic form (PCV2-associated systemic disease) the weight loss and wasting can lead to prolonged time to market, resulting in significant economic losses. Even though the morbidity is a moderate average of about 10%, the mortality of pigs with clinical signs can be well over 50%. In addition to the respiratory signs observed in younger pigs, infection of sows with PCV2 can lead to significant reproductive losses, mostly due to late-term abortions, stillbirths, and birth of piglets too weak to survive.
In many of the disease syndromes observed clinically, it is not quite clear exactly what role PCV2 plays. Environmental factors like overcrowding, presence of other pathogens, and poor ventilation have shown to also be involved in these multifactorial diseases. Control of PCV2 is aided by the availability of efficacious vaccines that have been shown to generate a good immune response. Vaccination seems to be able to control clinical signs and lessen the economic losses associated with them.
The clinical ramifications of PCV3 are at this point still relatively unknown as a full case definition has not been established, however reproductive failure appears to be the main issue associated with PCV3 while the impact on growing pigs remains unclear.
Polymerase chain reaction (PCR) is used to detect the presence of the virus in serum, raw semen, and oral fluid samples. PCR is a fast and accurate method of testing for the presence of the virus in an individual animal or in a pen-based sample. It is generally accepted that only high loads of virus are associated with overt clinical disease. Results from the PCR testing will aid in determination of the virus titer. General turnaround time is next day testing from receipt.
