Changes

==Pathogenesis==

==Pathogenesis==

 

Once PRRS virus gains entry to the host, primary replication occurs in regional or mucosal macrophages such as in the tonsil and the nasal and respiratory epithelium. After around twelve hours, viraemia occurs and the virus is disseminated systemically. Lymphatic transport

Following exposure to PRRS virus, primary replication

occurs in regional or mucosal macrophages (Rossow,

the tonsil, nasal and respiratory epithelium are sites of

primary replication after oronasal exposure. Viremia

can occur within 12 hours following exposure resulting

in systemic dissemination of the virus. Lymphatic transport

of PRRS virus and virus-infected macrophages to

of PRRS virus and virus-infected macrophages to

regional lymph nodes is also thought to occur.

regional lymph nodes is also thought to occur.