Infection results in prolonged diarrheal illness measured in weeks. Severe weight loss is a resulting complication. Because it takes as few as 1 to 10 organisms to cause life threatening illness, the organism causes very high rates of infection in group settings. Other pathogenic E. coli may cause similar symptoms and complications. Giardia is a protozoa that is more common to fresh bodies of water.
Infected people can be asymptomatic.
Hepatitis A is a virus that causes liver damage. Listeria is a bacteria particularly dangerous to pregnant women, their fetuses and newborns. Infected people can be asymptomatic. The CDC has produced two separate brochures warning of the potential hazards of Listeria. Salmonella is commonly found in poultry but has been associated with the feces of many animals including cattle and pigs.