Information for Healthcare Professionals

How are foodborne diseases diagnosed?

The infection is usually diagnosed by specific laboratory tests that identify the causative organism.

• Bacteria such as Campylobacter, Salmonella, E. coli O157 are found by culturing stool samples in the laboratory and identifying the bacteria that grow on the agar or other culture medium.
• Parasites can be identified by examining stools under the microscope.
• Viruses are more difficult to identify, as they are too small to see under a light microscope and are difficult to culture. Viruses are usually identified by testing stool samples for genetic markers that indicate a specific virus is present.

Many foodborne infections are not identified by routine laboratory procedures and require specialized, experimental, and/or expensive tests that are not generally available.

• If the diagnosis is to be made, the patient has to seek medical attention, the physician must decide to order diagnostic tests, and the laboratory must use the appropriate procedures.
• Because many ill persons to not seek attention, and of those that do, many are not tested, many cases of foodborne illness go undiagnosed, and most illnesses are not laboratory-confirmed.
  • For example, it is estimated that 29 Salmonella illnesses occur for every one that is laboratory-confirmed and that many hospitalizations and deaths caused by Salmonella infection are not ascertained

How are foodborne diseases treated?

There are many different kinds of foodborne diseases and they may require different treatments, depending on the symptoms they cause. Illnesses that are primarily diarrhea or vomiting can lead to dehydration if the person loses more body fluids and salts (electrolytes) than they take in.

• Replacing the lost fluids and electrolytes and keeping up with fluid intake are important.
• If diarrhea is severe, oral rehydration solution such as Ceralyte*, Pedialyte* or Oralyte*, should be drunk to replace the fluid losses and prevent dehydration. Sports drinks such as Gatorade* do not replace the losses correctly and should not be used for the treatment of diarrheal illness.
• Preparations of bismuth subsalicylate (e.g., Pepto-Bismol*) can reduce the duration and severity of simple diarrhea.
• If diarrhea and cramps occur, without bloody stools or fever, taking an antidiarrheal medication may provide symptomatic relief, but these medications should be avoided if there is high fever or blood in the stools because they may make the illness worse.

*CDC does not endorse commercial products or services.