The first and the most important condition at the beginning of PRRSV control program is to disrupt virus circulation in the reproductive herd.
The tissue damage is the consequence of direct apoptosis (and necrosis) of alveolar macrophage and their neighboring cells due to the release of apoptotigenic cytokines, reactive oxygen species, and nitric oxide.
Currently, no single RT-PCR assay could be recommended as a universal method allowing for detection of all PRRSV strains with optimal sensitivity.
In Korea, it is common to vaccinate sows as a whole-herd mass vaccination program, where all sows are vaccinated quarterly with a type 2 PRRSV vaccine. Therefore, it is recommended to vaccinate breeding females quarterly with additional type 1 PRRSV vaccine to control type 1 PRRSV infection.
Type 1 PRRSV is highly prevalent in Korean swine herds and currently reproductive failure is more important consequence of infection with type 1 PRRSV, than is respiratory diseases in growing pigs.
According to the present status and the experiences obtained during the previous one and a half year, Hungary will get free of PRRS by 2020.