According to the Jamestown Sun, health officials in Maclean County, North Dakota have linked an outbreak of Salmonella illnesses to an unlicensed caterer.  Aggie Jennings, who ran the catering company, has been ordered by health department officials to cease operations.   Patrons of three separate events catered by Jennings became ill last month.  According to the article:

State epidemiologist Kirby Kruger says shredded beef and pasta salad served by Jennings at a June 20 wedding have tested positive for salmonella. Taco meat from a June 13 wedding also tested positive for the salmonella strain.

Tests on the farm  found a strain of salmonella found in baby chickens. Jennings has chicks on her farm.

My guess is that  a licensed operation, inspected by trained health officials would have been less likely to have a problem.