From the Guidelines
Gastroenteritis is primarily caused by viral infections, with norovirus being the most common culprit, followed by other viruses like rotavirus, adenovirus, and astrovirus, which infect the digestive system and spread through contaminated food or water, close contact with infected individuals, or touching contaminated surfaces and then touching your mouth. The infection inflames the lining of the stomach and intestines, leading to symptoms like nausea, vomiting, diarrhea, stomach cramps, and sometimes fever, as noted in the 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea 1. Some key points to consider when evaluating the cause of gastroenteritis include:
- The majority of diarrheal illnesses are self-limited and identification of the infectious etiology often has little value to individual patients, but for certain infections, an organism-specific diagnosis is important to guiding clinical management 1
- Restricting testing to patients with bloody stools, fever, or abdominal tenderness can increase the likelihood of identifying a bacterial pathogen 1
- Risk factors for invasive nontyphoidal Salmonella infection include young and advanced age, impaired immunity due to human immunodeficiency virus (HIV) infection and cytotoxic chemotherapy, malnutrition, hemoglobinopathies, recent malaria, and cirrhosis 1
- Immunocompromised people are more likely to experience severe or prolonged illness, and diarrhea in immunocompromised patients may involve a broad spectrum of potential causes, including bacterial, viral, parasitic, and fungal pathogens depending on underlying immune status 1. Key considerations for treatment and prevention include:
- Treatment typically involves rest, staying hydrated with clear fluids, and gradually reintroducing bland foods as symptoms improve
- Over-the-counter medications such as loperamide (Imodium) can help control diarrhea in adults, while acetaminophen (Tylenol) can reduce fever and discomfort
- Prevention includes thorough handwashing, especially after using the bathroom and before handling food, avoiding sharing utensils with sick individuals, and properly washing fruits and vegetables.
From the Research
Causes of Gastroenteritis
- Gastroenteritis is caused by a variety of agents, including bacteria, viruses, parasites, toxins, and chemicals 2
- Viruses are the most common cause of gastroenteritis, followed by bacteria and parasites 3
- Norovirus is a frequent cause of both acute gastroenteritis and outbreaks of gastroenteritis 4, 5
- Rotavirus is also a common cause of acute gastroenteritis, especially in children 3, 6
Types of Gastroenteritis-Causing Agents
- Norovirus is divided into seven different genogroups (GI-GVII) and further classified into different genetic clusters or genotypes 4
- Noroviruses are highly contagious and can be spread directly from individual to individual or indirectly via contaminated food and water 4
- Bacteria, such as Clostridioides difficile, can also cause gastroenteritis, especially in individuals who have recently taken antibiotics 3
Symptoms and Complications
- Gastroenteritis is characterized by symptoms such as diarrhea, vomiting, fever, headache, and stomach pain 4, 3
- Complications of gastroenteritis can include dehydration, electrolyte imbalance, and postinfectious irritable bowel syndrome (IBS) 3
- In severe cases, gastroenteritis can lead to mortality, especially in young children, the elderly, and immunocompromised individuals 2, 4, 5