48 million

According to a statement [PDF] from the Centers for Disease Control and Prevention regarding foodborne illness due to known pathogens:

-Salmonella was the leading cause of estimated hospitalizations and deaths, responsible for about 28% of deaths and 35% of hospitalizations due to known pathogens transmitted by food.

-About 90% of estimated illnesses, hospitalizations, and deaths were due to seven pathogens: Salmonella, norovirus, Campylobacter, Toxoplasma, E. coli O157, Listeria and Clostridium perfringens.

-Nearly 60% of estimated illnesses, but a much smaller proportion of severe illness, was caused by norovirus.