An enteric infection is an inflammation of the gastrointestinal tract, including the stomach and intestines. This condition, broadly known as gastroenteritis, is sometimes called the “stomach flu,” though it is not caused by the influenza virus. These infections result from ingesting certain microorganisms and are a frequent cause of digestive distress globally.
Pathogens Causing Enteric Infections
The primary agents causing enteric infections are viruses, bacteria, and parasites. Viruses are the most frequent cause, with Norovirus being a prominent example known for spreading quickly in contained environments like schools and cruise ships. Rotavirus is another significant viral pathogen, though its incidence has decreased in some regions due to vaccination.
Bacterial infections are another major category, often linked to the consumption of contaminated food, a condition known as food poisoning. Salmonella species, for instance, are frequently found in raw or undercooked poultry, eggs, and meat. Shiga toxin-producing E. coli (STEC) can cause severe illness and is associated with undercooked ground beef and contaminated produce. Campylobacter is another common bacterium, transmitted through raw or undercooked poultry, unpasteurized milk, and contaminated water.
Parasitic infections, while less common than viral or bacterial ones in some areas, can cause prolonged illness. These organisms are often transmitted through water sources contaminated with feces. Giardia duodenalis is a microscopic parasite that causes an illness known as giardiasis, characterized by persistent diarrhea. Cryptosporidium is another waterborne parasite that can lead to a similar condition, which can be severe in individuals with weakened immune systems.
Common Symptoms and Potential Complications
The most common symptoms include diarrhea, which may be watery or bloody, and vomiting. Abdominal cramps, pain, and a low-grade fever are also typical.
The most significant complication is dehydration, caused by the loss of fluids and electrolytes from persistent diarrhea and vomiting. Signs include reduced urination, a dry mouth, and dizziness. In children, signs can also include lethargy, no tears when crying, and a sunken fontanelle. Dehydration is especially risky for young children, older adults, and those with compromised immune systems, and can lead to hospitalization if unmanaged.
Transmission and Prevention Strategies
Enteric pathogens spread through the fecal-oral route. This occurs via direct person-to-person contact, such as from unwashed hands preparing food. Indirect transmission happens by consuming food or water contaminated with fecal matter, or through contact with infected animals or their environments.
Prevention focuses on breaking the transmission cycle:
- Wash hands frequently with soap and water, especially after using the bathroom, changing diapers, and before handling food; use an alcohol-based hand sanitizer when soap is unavailable.
- Cook meat, poultry, and eggs to the recommended internal temperatures to kill bacteria.
- Prevent cross-contamination by using separate cutting boards for raw and cooked foods and by washing all produce.
- Drink water from a safe, treated source, particularly when traveling.
Medical Evaluation and Treatment Approaches
While most enteric infections resolve on their own, certain symptoms warrant medical attention, including severe dehydration, a high fever, bloody stools, or symptoms lasting more than a few days. A healthcare provider can diagnose the cause based on a physical exam and symptoms. In some cases, a stool sample is analyzed to identify the specific pathogen and guide treatment.
Treatment for most enteric infections, especially viral ones, involves supportive care to prevent dehydration. This is achieved by replenishing lost fluids and electrolytes with oral rehydration solutions, which are more effective than water alone. Severe dehydration may require intravenous (IV) fluids in a hospital.
Antibiotics are ineffective against viruses and are reserved for specific bacterial infections, such as typhoid fever or severe cases of Campylobacter or Shigella. A doctor determines if antibiotics are necessary based on the identified bacteria and illness severity. Inappropriate antibiotic use contributes to the development of resistant bacteria.