Transmissible gastroenteritis coronavirus carrier sow.

A sow infected with virulent transmissible gastroenteritis virus (TGEV) shed virulent virus in her feces for 18 months. The virus was isolated from rectal swabs beginning 2 days postexposure (PE) and continued at irregular intervals. Virus shedding was detected on 24 separate occasions. The titer of the virus shed ranged from < 1 x 10(2) pfu/ml to 7.2 x 10(3) pfu/ml, while the duration of the shedding ranged from 1 to 5 consecutive days. Inoculation of 3-day-old piglets with TGEV isolated from the sow proved the virus was virulent throughout the study. Virulent TGEV was isolated from the spleen, mesenteric lymph nodes, and the liver of the sow 544 days PE. This study demonstrates an apparently healthy sow can be a reservoir and shed virulent TGEV for an extended period of time.