The “Big 6” Foodborne Pathogens: What to Know

There are more than 250 known disease-causing organisms called pathogens that cause foodborne illnesses.

Of these, six spread easily through food and make many people sick.

These six pathogens are known as the “Big 6.”

As a food handler, you should know these big 6 foodborne pathogens, the symptoms they cause, the foods commonly associated with them, and how you can keep food safe from them.

The Big 6 foodborne pathogens

Here are the big 6 foodborne pathogens and what you need to know about each (1, 2):

Norovirus

Norovirus is commonly called the stomach flu or stomach bug.

It’s the most common cause of vomiting and diarrhea and foodborne illness.

A few norovirus particles is all it takes to make people sick.

There is no specific treatment for norovirus, but you should drink plenty of fluids to prevent dehydration.

• Type: Virus
• Symptom onset: 12–48 hours
• Symptoms: Diarrhea, stomach cramps, nausea, vomiting
• Symptom duration: 12–60 hours
• Common sources: Foods handled by an infected food handler, raw produce, shellfish from contaminated waters

How to prevent norovirus:

• wash your hands regularly
• rinse fruits and vegetables
• cook shellfish thoroughly
• let your manager or the person in charge know if you’re experiencing symptoms

Hepatitis A

Hepatitis A is a virus that affects the liver.

In rare instances, hepatitis A can cause liver failure and death, but this is more common in highly susceptible populations.

A vaccine exists for hepatitis A, but it’s still important to handle food safely to prevent it from spreading.

• Type: Virus
• Symptom onset: 15–50 days
• Symptoms: Dark urine, diarrhea, flu-like symptoms, jaundice, stomach pain
• Symptom duration: 2–12 weeks
• Common sources: Contact with an infected food handler, raw produce, shellfish from contaminated water

How to prevent hepatitis A:

• rinse fruits and vegetables
• cook shellfish thoroughly
• let your manager know if you’re experiencing symptoms

Shigella

Shigella bacteria cause a foodborne illness called shigellosis.

Most people recover without treatment, but highly susceptible populations may need antibiotics.

• Type: Bacteria
• Symptom onset: 4–7 days
• Symptoms: Diarrhea (may be bloody), fever, stomach cramps
• Symptom duration: 24–48 hours
• Common sources: Contaminated water, foods handled by an infected food handler, raw produce, uncooked foods

How to prevent Shigella:

• wash your hands regularly
• cook foods to safe minimum internal temperatures
• wash fruits and vegetables
• avoid cross-contamination
• let your manager know if you’re experiencing symptoms

Shiga toxin-producing Escherichia Coli (STEC)

Most strains of Escherichia Coli (E. Coli) are harmless and are actually an important part of a healthy digestive tract.

However, other strains like Shiga toxin-producing E. Coli (STEC) are harmful.

As the name suggests, this strain produces a toxin called Shiga.

STEC is most commonly heard about in the news in association with foodborne illness outbreaks.

• Type: Bacteria
• Symptom onset: 1–3 days
• Symptoms: Diarrhea (often bloody), stomach cramps, some vomiting
• Symptom duration: 3–7 days
• Common sources: Water or food contaminated with human feces

How to prevent STEC:

• wash your hands regularly
• rinse fruits and vegetables
• cook foods to safe minimum internal temperatures
• let your manager know if you’re experiencing symptoms

Salmonella Typhi

Salmonella Typhi causes typhoid fever.

Most people diagnosed in the United States with the illness have traveled to places where it’s more common.

Infected individuals can then spread it to food.

Doctors commonly prescribe antibiotics to treat typhoid fever.

• Type: Bacteria
• Symptom onset: 1–3 weeks
• Symptoms: Achiness, diarrhea, fever, stomach cramps
• Symptom duration: 2–4 weeks
• Common sources: Contaminated produce, poultry, meat, unpasteurized milk or juice

How to prevent typhoid fever:

• wash your hands
• rinse fruits and vegetables
• cook foods to safe minimum internal temperatures
• let your manager know if you’re experiencing symptoms

Salmonella (nontyphoidal)

Salmonella causes a foodborne illness called salmonellosis. The strains that cause salmonellosis are different than the strain that causes typhoid fever.

Most people can recover from a Salmonella infection but highly susceptible populations may need antibiotic treatment.

• Type: Bacteria
• Symptom onset: 6–72 hours
• Symptoms: Diarrhea, fever, nausea, stomach cramps
• Symptom duration: 4–7 days
• Common sources: Contaminated produce, poultry, meat, unpasteurized milk or juice

How to prevent Salmonella:

• wash your hands often
• rinse fruits and vegetables
• cook foods to safe minimum internal temperatures
• let your manager know if you’re experiencing symptoms

An overview of the big 6 foodborne pathogens

Here’s an overview of the big 6 foodborne pathogens:

Big 6 Foodborne Pathogen	Type	Symptom Onset	Symptoms	Symptom Duration	Common Sources
Norovirus	Virus	12–48 hours	Diarrhea, stomach cramps, nausea, vomiting	12–60 hours	Foods handled by an infected food handler, raw produce, shellfish from contaminated waters
Hepatitis A	Virus	15–50 days	Dark urine, diarrhea, flu-like symptoms, jaundice, stomach pain	2–12 weeks	Contact with an infected food handler, raw produce, shellfish from contaminated water
Shigella	Bacteria	4–7 days	Diarrhea (may be bloody), fever, stomach cramps	24–48 hours	Contaminated water, foods handled by an infected food handler, raw produce, uncooked foods
Shiga toxin-producing E. Coli (STEC)	Bacteria	1–3 days	Diarrhea (often bloody), stomach cramps, some vomiting	3–7 days	Water or food contaminated with human feces
Salmonella Typhi	Bacteria	1–3 weeks	Achiness, diarrhea, fever, stomach cramps	2–4 weeks	Contaminated produce, poultry, meat, unpasteurized milk or juice
Salmonella (nontyphoidal)	Bacteria	6–72 hours	Diarrhea, fever, nausea, stomach cramps	4–7 days	Contaminated produce, poultry, meat, unpasteurized milk or juice

If you have been diagnosed with or exposed to one of these illnesses, you must notify your manager since they are highly contagious.

The bottom line

The big 6 foodborne pathogens spread easily and quickly and can make people very sick.

They include norovirus, hepatitis A, Shigella, Shiga toxin-producing Escherichia Coli (STEC), Salmonella Typhi, and Salmonella (nontyphoidal).

Let your manager know when you’re sick, regularly wash your hands, cook food to their safe minimum internal temperature, and practice other basic food safety principles to avoid spreading the big 6 foodborne pathogens.