Persistent viruses interact with the immune system.
The ability to infect and inhibit T cell functions is being studied in vivo and in vitro. Virus-receptor studies examine the mechanism of initial infection of immune cells. Molecular techniques are being applied in studies of transmission and characterization of virus strains from feral pigs. Unique RFLP patterns and DNA isolation by PCR are being used to investigate the molecular epidemiology of pseudorabies in wild swine populations. Dunham, D.R. and Hahn, E.C. 1992.