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Foodborne illness pathogens

Most foodborne illness is caused by pathogenic bacteria or viruses in food.

Other less common foodborne illness occurs from accidental chemical poisoning and natural contaminants.

The most common types of foodborne illness are:

  1. bacterial eg Salmonella, Campylobacter, E.coli and Listeria
  2. viral eg Norovirus, Rotavirus and Hepatitis A
  3. intoxication caused by toxins produced by pathogens such as Staphylococcus aureus, Bacillus cereus and Clostridium perfringens.

Symptoms and the most frequent food vehicle will vary depending on the type of pathogen.

(Wide table: scroll/swipe sideways if not all columns are displayed.)


image of pathogen **

Typical incubation period (time between eating and onset of symptoms)

Typical symptoms

Typical food vehicles *

Bacillus cereus toxin (vomiting and diarrhoea)


1 - 6 hours

6 - 24 hours 

Sudden onset of severe nausea and vomiting

Abdominal cramps, nausea and watery diarrhoea

Improperly refrigerated cooked rice and pasta, and fresh noodles

Meats, stews, gravy



2 - 5 days

Fever, nausea, abdominal cramps and diarrhoea (sometimes bloody)

Raw and undercooked poultry, unpasteurised milk and contaminated water

Clostridium perfringens toxin


6 - 24 hours

Abdominal cramps, watery diarrhoea and nausea

Meats, poultry, gravy, dried or precooked foods

Escherichia coli including (STEC)


2 - 10 days more commonly 3 - 4 days

Diarrhoea (often bloody), abdominal cramps

Improperly cooked beef, unpasteurised milk and juice, sprouts and contaminated water

Hepatitis A


2 - 7 weeks

Jaundice, fatigue, loss of appetite, nausea

Raw or poorly cooked seafood harvested from contaminated waters, ready-to-eat foods handled by an infected food handler

Listeria monocytogenes


3 days -
10 weeks

Meningitis, sepsis, fever

Soft cheeses, unpasteurised milk, ready-to-eat deli meats



24 - 48 hours

Fever, nausea, vomiting, abdominal cramps, diarrhoea and headache

Poorly cooked shellfish, ready-to-eat foods touched by an infected worker



6 – 72 hours,
usually 12-36 hours

Headache, fever, abdominal cramps, diarrhoea, vomiting and nausea

Undercooked poultry, raw egg desserts and mayonnaise, sprouts, tahini

Staphylococcus aureus toxin


0.5 – 8 hours

Sudden onset of vomiting and abdominal cramps

Cream desserts and pastries, potato salad

Vibrio parahaemolyticus


4–30 hours, usually 12-24 hours

Nausea, vomiting, abdominal cramps and watery diarrhoea

Undercooked or raw seafood.

*The foods shown in the table have previously been found to be the source of the pathogens listed. This does not mean that these foods are always unsafe to eat  that such pathogens are always present, or that only these foods can carry the pathogen.

**Image credits: Partnership for Food Safety Education (USA); Laboratory of Clinical and Epidemiological Virology, Catholic University of Leuven (Belgium); HealthNJ, Univesity of Medicine and Dentistry of New Jersey (USA).