39-year-old Jerri Reges got severe stomach cramps after eating a hoagie at a convenience store July 5, becoming one of more than 300 people sickened in a recent salmonella outbreak that has hit five states. Roma tomatoes are believed to be the cause.

Tainted fresh foods pose more concerns than others because fruits and vegetables are often eaten raw or lightly cooked. That means salmonella, cyclospora, shigella, E. coli and other pathogens often aren’t killed before eating, and they generally can’t be removed by washing.

International and federal laws don’t allow the United States to set tougher safety rules for imported produce than for domestic products. Though the Food and Drug Administration tightened seafood and juice regulations after outbreaks in the late 1990s, officials are still studying whether to tighten fruit and vegetable standards.

The CDC estimates 76 million Americans get foodborne illnesses each year, based on a study of 1997 statistics, said Dr. Robert Tauxe, chief of CDC’s foodborne and diarrheal diseases branch. In that study, the CDC concluded that 325,000 Americans are hospitalized and 5,000 die each year, but that one in 38 cases is never reported.

Those numbers are based on the assumption that millions of people, unlike Reges, are never hospitalized and blame their illness on a virus or the flu.

The CDC is now actively tracking foodborne illnesses in nine states and using those numbers to set nationwide estimates.