Table 1 Detection and removal of certain viruses

Source of the virus

Endogenous

exogenous

exogenous

exogenous

Detection method

Realtime-PCR, droplet digital PCR

Serological methods, duplex real-time PCR

Serological methods, real-time PCR

multiplex real-time PCR[69]

Detection sites

Any tissue, organ.

Serological testing performed on blood samples, nucleic acid testing performed on nasal swabs, spleen, kidney.

Nucleic acid testing performed on muscle, urine, serum, and feces samples.

In most tissues and body fluids, with serum and lymphoid tissue being the main sites

Virus removal from pig

Gene editing

PCMV can be removed with a high probability by early weaning, colostrum deprivation and cesarean derivation

Divide-column breeding, farm disinfection, isolate negative pig groups.

use commercial vaccines.

Genetically Modified Pigs

Gene-edited pigs with internal PERV copies partially or completely knocked out.

N/A

N/A

N/A

RNA interference

Anti-PERV shRNA targeting the gag and pol genes  [57]

N/A

Targeting the ORF3 gene of HEV GT3.

Target sequence in the Rep gene encoding region [70]

vaccine

N/A

N/A

vaccine candidates, such as intramuscular vaccine derived from a gt 4 strain, HEV p179

Commercial vaccines, such as inactivated vaccines, or subunit vaccines based on the ORF2 protein of PCV2.