Transmission of pathogenic E coli mainly occurs through consumption of food or water contaminated with human or animal faeces. Person-to-person transmission may also occur, but it is less common.
| Pathotype | Clinical Details |
| EAEC | Transmission of EAEC is generally by the faecal-oral route via contaminated food and water. EAEC cause an inflammatory diarrheal illness characterized by watery and sometimes bloody stool, accompanied by low grade fever, vomiting, and abdominal pain. Asymptomatic carriage can occur. |
| EPEC | EPEC are a significant cause of infantile diarrhoea particularly in developing countries. EPEC do not produce enterotoxins or Shiga-like toxins instead causing damage to the gut by direct attachment. Infection can result in prolonged or persistent diarrhoea. . Asymptomatic carriage of EPEC also occurs. |
| ETEC | ETEC are an important cause of diarrhoea in developing countries especially among children, and are the most common bacterial cause of watery diarrhoea in travellers returning from abroad. Illness occurs 1-3 days after exposure and usually lasts 3-4 days although some people may experience more prolonged symptoms. ETEC may also be carried asymptomatically |
| STEC | May also be referred to as Verocytotoxin producing E coli (VTEC) or Enterohaemorrhagic E Coli (EHEC) STEC are a primary cause of bloody diarrhoea and can progress to a potentially fatal condition known as haemolytic uremic syndrome. The serogroup E coli 0157 is one of the most common strains to cause serious illness. STEC are important foodborne pathogens. Infections may also be waterborne, transmitted person-to-person, or via contact with animals, especially cattle, which are a reservoir for STEC. |
| EIEC | EIEC invades the colon and produce a watery diarrhoea syndrome that is identical to that caused by Shigella. |
| Shigella | Shigella are typically transferred through person-to-person contact or ingestion of contaminated food or water (humans and other primates are the only known animal reservoirs). Those most at risk of infection include children in child care centres, overseas travellers and men who have sex with men Severe illness may occur in infection with S dysenteriae whilst S sonnei tends to produce milder symptoms. Asymptomatic carriage can occur. |