Which bacterium is the most common cause of diarrhea?

Campylobacter jejuni is widely recognized as the most common bacterial cause of diarrhea. It is a leading cause of gastroenteritis worldwide, particularly in developed countries. Infection with Campylobacter typically occurs through the consumption of contaminated food, especially undercooked poultry, unpasteurized milk, or contaminated water. Symptoms of infection generally include diarrhea, abdominal pain, fever, and vomiting.

While Escherichia coli can also cause diarrhea, particularly certain pathogenic strains known to lead to outbreaks, it is not the most common bacterial cause for the general population. Salmonella enterica is another notable pathogen associated with foodborne illness but does not surpass Campylobacter in incidence rates associated with diarrhea. Clostridium perfringens is less frequently identified as a leading cause of diarrhea; it is more typically associated with food poisoning from meats or gravies that are not kept warm enough.

Understanding the specific characteristics and incidence of these pathogens helps in recognizing patterns in foodborne illnesses and implementing appropriate public health measures.