Episodes of food poisoning may have serious long-term consequences -- including kidney failure or mental retardation -- particularly among children, researchers say.
A new report that reviews previous data has found that five common foodborne pathogens may increase the risk of serious complications, according to lead author Tanya Roberts, of the Center for Foodborne Illness in Grove City, Pa.
"Our report addresses the fact that most foodborne pathogens can cause severe disease in some small probability of cases," Roberts said during a press briefing. "These serious or long-term complications include kidney failure, paralysis, seizures, hearing and visual impairment, and mental retardation."
The five major pathogens are Campylobacter, E. coli, Listeria monocytogenes, Salmonella, and Toxoplasma gondii. But more than 200 pathogens can contaminate food and cause disease, Roberts said.
While the severity of the acute infection varies greatly, depending on the pathogen and the patient's own vulnerability, the most common symptoms are diarrhea and vomiting. But even after a patient recovers from these symptoms, they may have to deal with longer-term effects.
Researchers aren't sure exactly how prevalent the long-term effects are. That's why Roberts and other researchers have called for a strong national surveillance network to keep track of cases of foodborne illness and monitor them for long-term effects.
"There's a great deal of uncertainty about the magnitude of these problems and the scope of the issue," said Craig Hedberg, of the University of Minnesota School of Public Health, who was not involved in the study.
"That uncertainty springs from the fact that we don't have good surveillance for the diseases, much less long-term follow-up of cases to really estimate the rate of occurrence for these serious conditions."
Roberts said the next step would be to set up a systemized reporting system "to follow acute foodborne illnesses and be more definitive about the long-term side effects that occur."
In their review of the literature, the researchers found that Campylobacter infection is associated with Guillain-Barre syndrome, the most common cause of paralysis in the U.S. It can also trigger arthritis, heart infections, and blood infections, she said.
E. coli poses a great risk to children, she said, especially regarding hemolytic uremic syndrome, or bloody stool. It is the leading cause of acute kidney failure in children in the U.S., and has been tied to end-stage kidney disease, neurological complications, and insulin-dependent diabetes.
Listeria monocytogenes has been associated with infections of the brain and spinal cord, resulting in serious neurological dysfunction or death. Most reported cases occur in children under age 4, and about one in five people die as a result of infection, Roberts said. It can also lead to miscarriage, premature birth, or stillbirth in pregnant women.
Salmonella can trigger reactive arthritis, and Toxoplasma gondii infections can lead to cognitive or visual disabilities.
Food safety has been a concern recently because of large national outbreaks, which have raised doubts about the safety of the nation's food supply and undermined consumer confidence in food.
In July, the House of Representatives passed the Food Safety Enhancement Act of 2009, and the Senate will mark up similar legislation next week.
Sen. Bob Casey (D-Pa.), who introduced his own food safety legislation along with Sen. Richard Durbin (D-Ill.), titled the Eat Safe Act (S.B. 429), said smuggled food is a major safety problem and will work to have that part of his bill incorporated into the Senate's final version.
"These smuggled food and agricultural products . . . pose a threat to our economy and security," he said. "The legislation I have would authorize funding for the Department of Agriculture and the FDA to bolster their efforts by hiring additional personnel to detect and track smuggled products."
Hedberg said the most important investments in the food safety system will be increased surveillance, which "will go a long way toward creating a framework from which we can do long-term assessments of cases to come up with better answers as to the frequency and the overall impact of these diseases."
"Then, we'll have much better tools to figure out how best to prevent and mitigate harm from these infections," he added.
Roberts said foodborne illness "must be recognized as a serious public health issue if we want to make meaningful progress in reducing sickness, injury, death, and long-term complications associated with foodborne disease."