Bacteria and Viruses

Bacteria and viruses are the most common cause of food poisoning. The symptoms and severity of food poisoning vary, depending on which bacteria or virus has contaminated the food.

The bacteria and viruses that cause the most illnesses, hospitalizations, and deaths in the United States are:

• Salmonella
• Norovirus (Norwalk Virus)
• Campylobacter
• E. coli
• Listeria
• Clostridium perfringens.

General Information

Foodborne Illness A-Z (CDC)
Directory of foodborne illnesses with links to detailed information.

• Bacterial Causes
• Viral Causes

Foodborne Illness & Disease (USDA)
General information plus links to information on specific diseases.

Bad Bug Book (FDA)
Basic facts regarding foodborne pathogenic microorganisms and natural toxins.

Charts and Tables

Foodborne Illness: What Consumers Need to Know (USDA)
General information, including a chart on 8 bacteria that cause foodborne illness.

Foodborne Illness-Causing Organisms in the U.S. - What You Need to Know (FDA)
General information, including a chart on 16 organisms that cause foodborne illness.