More than 50,000 people got sick or died from something they ate in a hidden epidemic that went undiagnosed by the nation’s public health departments during a five-year period, according to Thomas Hargrove of the Scripps Howard News Service.

Scripps studied 6,374 food-related disease outbreaks reported by every state to the federal Centers for Disease Control and Prevention from Jan. 1, 2000, through Dec. 31, 2004. Slovenly restaurants, disease-infested food-processing plants and other sources of infectious illness go undetected all over the country, but much more frequently in some states than others.

The causes of nearly two- thirds of the outbreaks in that period were listed as "unknown." The poor track record of so many state labs also raises chilling questions about their ability to deal with a foodborne terrorist attack.

The Scripps study also found that the disease went undiagnosed in 4,054 of the 6,374 reported outbreaks. Those unknown causes sickened or killed 50,968 people. Every year, an estimated 5,000 Americans die from food-based pathogens such as salmonella, E. coli, shigellosis and campylobacter. Another 325,000 people are hospitalized.