What is E. coli?
E. coli, short for Escherichia coli, are bacteria that live in the intestines of people and animals. Most E. coli are harmless and even helpful, but some strains can cause illness. The types that cause disease are called pathogenic E. coli.
Some examples of pathogenic E. coli include:
- Enterotoxigenic E. coli (ETEC) – Cause traveler’s diarrhea
- Enteropathogenic E. coli (EPEC) – Cause diarrhea, especially in children
- Enterohemorrhagic E. coli (EHEC) – Can cause severe illness like hemorrhagic colitis and hemolytic uremic syndrome (HUS)
- Enteroinvasive E. coli (EIEC) – Cause symptoms similar to shigellosis
The most concerning type is EHEC, which includes a strain called O157:H7. This strain produces Shiga toxin and can cause severe bloody diarrhea, stomach cramps, vomiting and fever.
E. coli are transmitted through ingestion. Common sources include:
- Undercooked or raw meat, especially ground beef
- Unpasteurized milk and cheese
- Contaminated produce like lettuce and spinach
- Contact with infected people or animals
- Contaminated recreational water like lakes and pools
Proper food handling and cooking can prevent E. coli illness. Thorough handwashing after using the bathroom or contact with animals can also reduce spread.
Can E. coli infections resolve without treatment?
In otherwise healthy adults and children, E. coli infections may resolve on their own without medication. However, there are some important caveats:
- Illness can last 7-10 days without treatment. Antibiotics can shorten duration.
- Letting infection run its course increases risk of spreading to others.
- Some people are at higher risk for complications like HUS, which can lead to kidney failure. These include young children, older adults, pregnant women, and those with weakened immune systems.
- Rarely, E. coli can spread from the intestines to the bloodstream and cause a life-threatening blood infection called sepsis.
So while E. coli can technically resolve without antibiotics, treatment is often recommended, especially for those at risk for severe illness.
When should you see a doctor for E. coli?
See a doctor if you experience:
- Diarrhea lasting more than 3 days
- Fever over 101.5°F (38.6°C)
- Blood or pus in the stool
- Signs of dehydration like excessive thirst, dry mouth, infrequent urination
- Abdominal pain that is severe or persistent
- Vomiting that prevents keeping down fluids
- Diarrhea or other symptoms after taking antibiotics for another condition
Prompt medical attention is crucial if the infection spreads beyond the intestines. Seek emergency care for:
- Confusion, drowsiness, or other neurological changes
- Difficulty breathing
- Rapid heart rate
- Low blood pressure
These can be signs of sepsis, which requires hospitalization and IV antibiotics. People with signs of HUS, like decreased urination, bruising, bleeding, and severe fatigue, also need emergency treatment.
How do doctors treat E. coli infections?
Doctors use several strategies to treat E. coli:
Antibiotics
Antibiotics can shorten the duration of illness and lower the risk of complications. Options include:
- Ciprofloxacin
- Trimethoprim-sulfamethoxazole
- Azithromycin
- Ampicillin
Some E. coli strains have become resistant to certain antibiotics, so doctors may take a stool culture to identify the best option.
Hydration
Dehydration is a common and dangerous complication of diarrhea. Doctors recommend drinking clear fluids, electrolyte solutions, or broths. For severe dehydration, IV fluids may be needed.
Antidiarrheal Medication
Medicines like loperamide (Imodium) and bismuth subsalicylate (Pepto-Bismol) can help control diarrhea. But they should be used cautiously as they could worsen invasive infections.
Hospitalization
People with severe dehydration, bloody diarrhea, kidney complications, or sepsis require inpatient treatment. Care focuses on IV fluids, nutrition, antibiotics, and preventing further complications.
How long is a person contagious with E. coli?
Those infected with E. coli are most contagious during the worst of their illness, when the bacteria is actively being shed in stool. But proper hygiene is important to prevent spread, even after you start feeling better.
Here are general guidelines for how long E. coli can be contagious:
- Symptomatic illness: Contagious during acute gastroenteritis until several days after diarrhea stops. Some reports suggest shedding for 7-14 days.
- Asymptomatic carriers: May shed bacteria intermittently for months after exposure.
- Children under 5: Often carry E. coli in their intestines without illness. Their hygiene habits mean they can easily spread bacteria.
To be on the safe side, continue diligent handwashing and bathroom hygiene for at least 1-2 weeks after diarrhea ceases. Avoid preparing food for others during this time. Children may need stool cultures to confirm when they are no longer shedding bacteria.
Can E. coli infections be prevented?
Practicing good hygiene and food safety habits can help prevent E. coli transmission:
- Cook meats thoroughly, especially ground beef to at least 160°F (71°C). Use a food thermometer to verify temperature.
- Avoid unpasteurized dairy products.
- Wash fruits and vegetables well before eating.
- Prevent cross contamination in kitchen by using separate cutting boards for produce and meat.
- Drink only treated water from municipal sources or bottled water when traveling.
- Wash hands with soap and water after using bathroom, changing diapers, handling animals, or before preparing food.
- Stay home from work, school, or daycare while ill with diarrhea.
- Avoid swimming pools, hot tubs, lakes, or ocean water if you have diarrhea.
Vaccines for some pathogenic E. coli strains are in development but none are commercially available yet.
Conclusion
While E. coli often causes self-limited illness, antibiotics and medical care improve outcomes, especially for high-risk groups. Seek prompt treatment for bloody or persistent diarrhea, signs of dehydration, or any systemic symptoms. Preventing E. coli relies on good hygiene and food safety practices. Though evidence is limited, bacteria may be shed for up to two weeks after symptoms end, so maintain diligent handwashing during recovery. While E. coli can sometimes resolve on its own, treating and preventing transmission benefits both individual and public health.
