Illinois plant processes 12,600 hogs per day, representing approximately 3% of U.S. fresh pork supplies. St. Charles, Ill., dry sausage plant also closed.
Facility adds free, on-site testing of symptomatic team members in coordination with health officials.
Dry-mill facilities in Cedar Rapids, Iowa, and Columbus, Neb., will be closed for at least next four months.
USDA says official reported cases do not reflect continuing severity of situation in China.
The Indiana processing facility produces 3 million pounds of pork daily and helps support more than 250 independent family farmers from across nine states.