Salmonella contamination is primarily found in poultry products because its part of their normal flora. Beef tends to be contaminated with E Coli. Commercially prepared raw diets are just as likely to be contaminated as a BARF diet, with some studies suggesting up to a 45% contamination rate of Salmonella in the commercially prepared raw.
Another study showed that when healthy dogs are fed commercially prepared raw food contaminated with Salmonella, they shed the bacteria even though they do not show symptoms of the infection.
So, for some people, feeding even a commercially prepared raw diet puts them at risk. There has been an upswing in the number of drug resistant Salmonella outbreaks. People with compromised immune systems as well as the elderly and infants are at increased risk. Unfortunately, even the normally touted methods of eliminating contamination (bleach and hot water) is minimally effective in eliminating salmonella
(
Survival of Salmonella Copenhagen in food bowls fo... [Can Vet J. 2006] - PubMed - NCBI)