Causes and Risk Factors of E. Coli Infection

Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most strains of E. coli are harmless, but some can cause infections and severe illness. E. coli infection often spreads when a person eats food or drinks water that has been contaminated with feces containing harmful strains of the bacteria.
Some common risk factors and causes of E. coli infection include:
• Consuming undercooked or contaminated beef, especially ground beef. This is a major cause of outbreaks due to E. coli O157:H7 strain. Eating undercooked beef, such as rare hamburgers, that has been contaminated with E. coli from the intestines of cattle is a leading cause of infection. The high fat content of ground beef also allows the bacteria to survive for long periods.
• Exposure to contaminated water or food during travel to developing countries. This includes drinking untreated water or eating raw fruits and vegetables washed in contaminated water. Travelers to developing nations are at higher risk due to poorer sanitation and hygiene standards. Contaminated water and foods like salad, sprouts and unpeeled fruit can harbor E. coli and other bacteria that cause diarrhea and infection.
• Contact with infected animals or their environments at farms, petting zoos, fairs, or even home. This includes touching infected cattle or sheep, their feces, or surfaces that they have contaminated. Visiting farms, petting zoos and agricultural fairs where you can come in contact with infected animals or their droppings is a major risk factor, especially for young children. Even having a petting zoo at home or letting children touch farm animals on a family trip poses risks.
• Poor hygiene like inadequate hand washing, especially after using the bathroom or changing diapers. This can allow E. coli to enter the mouth and spread infection. Not washing hands properly after using the toilet, changing diapers or handling infected items is a key risk factor for E. coli infection. The bacteria can enter through the mouth and spread if hands are not washed.
• Very young age or a weakened immune system. Young children, elderly, and immunocompromised individuals are more susceptible to E. coli infection and severe complications. Those with weaker immune systems such as young children, older adults and people on immunosuppressants have higher risks of infection and life-threatening complications like hemolytic uremic syndrome.
• Consuming raw or undercooked sprouts, like alfalfa sprouts. Sprouts can be a source of outbreaks if the seeds are contaminated with E. coli before sprouting. The warm, humid conditions required for sprouting are ideal for the growth of E. coli bacteria if the seeds are contaminated. Alfalfa and other sprouts have been linked to numerous E. coli outbreaks.
• Swallowing water from lakes, rivers, ponds, or streams contaminated with sewage or feces from people or animals. This is more likely to occur during recreational activities like swimming, boating, or waterskiing. Swallowing water that has been contaminated with feces from humans or animals is a major risk factor for infection with strains of E. coli that can cause severe illness.
• Living in or traveling to an area where there is an active outbreak of E. coli infection. During outbreaks, the bacteria can spread more easily in the community through contaminated food, water or contact with infected individuals. Outbreaks of E. coli are more likely to occur in areas with poor sanitation and limited access to clean water. Living in or traveling to such areas during an active outbreak significantly increases the risk of infection.