Enterotoxigenic Escherichia coli (ETEC) is a strain of E. coli bacteria known to cause diarrheal illness. This bacterium is a primary cause of “traveler’s diarrhea,” affecting individuals who visit regions with less developed sanitation infrastructures. ETEC also contributes to diarrheal disease in young children residing in these same areas. The illness results from toxins produced by the bacteria once they colonize the small intestine.
How ETEC Spreads
Infection with ETEC primarily occurs through the fecal-oral route, often when food or water becomes tainted with human or animal feces. Consuming unpurified water, including ice made from such water, is a common way to contract the infection.
Food items can also serve as vehicles for transmission. Raw or undercooked foods, as well as unpeeled fruits and vegetables that may have been washed in contaminated water, pose a risk. For instance, salads or fresh herbs washed in unsafe water can transmit the bacteria. While less common, person-to-person spread is possible, especially in settings with poor hygiene practices.
Symptoms of an ETEC Infection
Symptoms of an ETEC infection include profuse, watery, non-bloody diarrhea. Individuals often experience abdominal cramps, nausea, and sometimes vomiting. Low-grade fever, chills, loss of appetite, headache, and muscle aches can also occur.
The incubation period usually ranges from 1 to 3 days, but can be as short as 10 hours or as long as 72 hours. Most cases are self-limited, with symptoms resolving within 3 to 5 days. However, symptoms may persist for up to three weeks.
Dehydration represents the most significant complication of ETEC infection, particularly for young children and the elderly. Signs of dehydration include increased thirst, dry mouth, infrequent urination, and reduced tear production. Severe fluid loss can become life-threatening if not addressed promptly, requiring fluid and electrolyte replacement.
Treatment and Management
Replacing lost fluids and electrolytes is the primary approach for managing an ETEC infection. Oral rehydration solutions (ORS) are the most effective option, containing the correct balance of salts and sugars to aid in fluid absorption. If commercial ORS is unavailable, a homemade solution of clean water, sugar, and salt can be used. Clear broths and plain water can also help maintain hydration.
Most individuals recover with supportive care alone and do not require additional treatment. However, medical care should be sought if there are signs of severe dehydration, a high fever, or if symptoms persist for more than a few days. In severe cases or for certain travelers, antibiotics may be prescribed to reduce the duration and severity of the illness. Azithromycin is a preferred antibiotic, while ciprofloxacin and rifaximin may be alternatives, depending on local resistance patterns. Over-the-counter anti-diarrheal medications, such as loperamide, can provide symptomatic relief but should be used with caution and under medical guidance, especially in cases with fever or bloody stools, or in young children.
Prevention for Travelers and at Home
Preventing ETEC infection involves careful attention to food and water safety, especially when traveling to regions where the bacteria are common. A common guideline for travelers is “Boil it, cook it, peel it, or forget it”. This means consuming only bottled or purified water with an intact seal, and avoiding ice cubes made from tap water. Beverages like tea or coffee, if made with just-boiled water, are safe.
Eating only food that is thoroughly cooked and served steaming hot helps reduce risk. Raw salads, uncooked vegetables, and unpeeled fruits should be avoided unless they can be peeled by the consumer after being rinsed with safe water. Street vendor food should be approached with caution, as hygiene standards may be inconsistent. Frequent and thorough handwashing with soap and clean water is also highly effective in preventing spread. This practice is particularly important before preparing or eating food, and after using the bathroom.