What causes enteritis (inflammation of the intestines)?

From the Guidelines

Enteritis is primarily caused by infectious agents, with norovirus and Salmonella enterica subspecies being the leading pathogens, as highlighted in the 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea 1. The most common causes of enteritis include:

• Viral infections: Norovirus, which accounts for 58% of gastroenteritis cases, and rotavirus, which was the most common pathogen among children <5 years before the introduction of the rotavirus vaccine 1.
• Bacterial infections: Salmonella enterica subspecies, which exceeds norovirus as a cause of hospitalization (35% vs 28%) and death (28% vs 11%) 1, as well as other bacteria like Campylobacter, Shigella, Yersinia, and E. coli O157.
• Other factors, such as food intolerances, certain medications, and radiation therapy, can also contribute to the development of enteritis. To prevent enteritis, it is essential to practice good hygiene, including handwashing, and ensure proper food handling and preparation, as emphasized in the guidelines 1. If symptoms of enteritis occur, it is crucial to stay hydrated and consider seeking medical attention if symptoms are severe or persist, as some causes may require specific treatments like antibiotics for bacterial infections or dietary changes for food intolerances. The inflammation in enteritis occurs when the intestinal lining becomes irritated or infected, leading to symptoms like diarrhea, abdominal pain, and sometimes fever, as described in the guidelines 1. Understanding the causes of enteritis is vital for both prevention and appropriate treatment, and the guidelines provide a comprehensive overview of the diagnosis and management of infectious diarrhea 1.

From the Research

Causes of Enteritis

• Bacterial infections are a common cause of enteritis, with Salmonella, Shigella, and Campylobacter species being the most common causes of acute bacterial enteritis in the United States 2
• These pathogens can cause enteritis by invading the intestinal mucosa and impairing the epithelial barrier, leading to a loss of water and solutes and facilitating the uptake of harmful antigens 3
• Viral agents, such as Norwalk virus, and parasites, such as Giardia lamblia and Cryptosporidium parvum, can also cause enteritis 4
• The symptoms of enteritis can vary depending on the causative agent, but can include diarrhea, abdominal pain, and fever

Risk Factors for Enteritis

• Immunocompromised individuals, the young, and the elderly are susceptible to developing more severe systemic infections 2, 5
• Poor handwashing and personal hygiene can contribute to the spread of enteritis-causing pathogens 2
• Foodborne illnesses, such as those caused by non-typhoid Salmonella spp., Campylobacter spp., Shigella spp., and Yersinia enterocolitica, can increase the risk of chronic gastrointestinal disorders, including irritable bowel syndrome, dyspepsia, constipation, and gastroesophageal reflux disease 6

Pathogenesis of Enteritis

• Salmonella-induced enteritis is a complex process that involves the type III secretion systems used to inject bacterial proteins into host cells, and the host's immune response, including the production of cytokines 5
• Campylobacter-induced enteritis involves the invasion of the intestinal mucosa and the impairment of the epithelial barrier, leading to a loss of water and solutes and facilitating the uptake of harmful antigens 3
• The pathogenesis of enteritis can vary depending on the causative agent, but often involves the disruption of the intestinal epithelial barrier and the activation of the host's immune response 4, 3