Left to right: Medical illustrations of Campylobacter, non-typhoidal Salmonella and Shigella. (CDC)

Food-borne illnesses killed hundreds of people and hospitalized thousands last year, according to the Centers for Disease Control and Prevention, which reported Thursday that progress has been made controlling some pathogens but conceded that more work remains to be done with others.

Numbers collected on 48 million people at 10 sites across the United States showed that 71 people died and more than 4,400 were hospitalized in 2014. (CDC officials said at a telephone briefing Thursday that the national total could be roughly estimated by multiplying their statistics to reflect the U.S. population of about 320 million.) Overall, an official said, one person in six becomes ill each year from eating contaminated food.

Listeria was by far the most dangerous bacterium in the food supply in 2014, though outbreaks were rare. It killed 18 of the 118 people who contracted it and put almost all of them in the hospital, according to the statistics released in the CDC's Morbidity and Mortality Weekly Report.

A listeria outbreak traced to prepackaged caramel apples -- one of four multistate outbreaks in 2014 -- killed three people last year, and another traced to Blue Bell ice cream has killed three more people in 2015.

[Listeria outbreak that killed three is traced to California apple supplier]

The total number of listeria cases hasn't changed much since 2006 to 2008, said Patricia Griffin, chief of the enteric diseases epidemiology branch of the CDC's division of Foodborne, Waterborne and Environmental Diseases. But the numbers are down sharply from 20 years ago, probably because of better controls in the production of processed meats, such as turkey and hot dogs, she said.

[FDA: Listeria detected in Blue Bell ice cream plants as far back as 2013]

Salmonella was the most common food-borne bacteria in 2014, with 7,452 cases in the CDC data, followed closely by campylobacter, with 6,486 cases. The CDC report noted progress controlling some types of salmonella, including a 27 percent decline since 2006-2008 in the Typhimurium type, which can come from poultry. But overall salmonella rates remained roughly unchanged, Griffin said, noting that government agencies will need to step up interventions that target the bacteria.

However, the incidence of campylobacter infections rose 13 percent. The common bacteria cause diarrhea and fever and usually come from eating undercooked poultry.

[Mutant, drug-resistant stomach bug is spreading in the U.S.]

Officials hailed a 32 percent drop in the incidence of Shiga toxin-producing Escherichia coli 0157 (STEC 1057) infections, which are associated with food, often beef, that has been contaminated by animal feces.

Overall, Griffin said, "the news is mixed. Some infections declined but others increased and most did not change. Clearly more work is needed."

[The most distinct cause of death in each of the 50 states]