1. Food poisoning with E. coli Farid Hedayati, MPH student Walden University PUBH Instructor: Dr. Robert Marino Summer, 2011  
The audience of this presentation is the general public. This presentation mainly tries to educate public to be more cautious about food borne diseases such as the ones caused by E. coli. Frequent outbreaks of E. coli in recent years in the United States and other countries indicate an alarming increase in public health policies violence because of lack of proper sanitation in any stages of food chain. E. coli infection can be prevented if everyone including those who are involve in food production, processing, manufacturing, and preparation follow simple instructions in proper personal and environmental hygiene. Frequent and proper hand washing and sanitation of food processing and preparation surfaces and environment could greatly reduce the magnitude of outbreaks and even eliminate its spread.

2. Expected Learning Outcomes
After this presentation you should be able to:
Describe E. coli as a pathogen
Define the impact of E. coli on their personal health
Implement and develop an effective strategy to prevent E. coli infection in their household
Recognize the importance of personal hygiene
By the end of this presentation everyone should be able to:
1.Describe E. coli as a pathogen
2.Define the impact of E. coli on their personal health
3.Implement and develop an effective strategy to prevent E. coli infection in their household
4.Recognize the importance of personal hygiene

3. Escherichia coli E. coli is a normal flora of human gut (WHO, 2011).
Enterohemorrhagic E. coli or EHEC can cause severe foodborne diseases (WHO, 2011).
E. coli O157:H7 is the most frequent serotype of EHEC (WHO, 2011).
EHEC makes Shiga toxin (CDC, 2011).
It is transmitted to humans primarily through consumption of contaminated foods (WHO, 2011).
Center for Disease Control and Prevention. Escherichia coli O157:H7 and other Shiga toxin-producing Escherichia coli (STEC). Retrieved 07/23/
World Health Organization. Escherichia Coli. Retrieved 07/23/
Escherichia coli or E. coli is a bacterium that is considered as normal flora and it is commonly found in the gut of humans and warm-blooded animals. Most strains of E. coli are harmless and would not cause any disease to human host. However, there are some strains such as enterohemorrhagic E. coli or EHEC that can cause severe food borne diseases. E. coli O157:H7 is an EHEC serotype that has frequently been involved in outbreaks in recent years. EHEC makes a specific type of toxin called Shiga toxin. Shiga toxin is the underlining cause of all symptoms and diseases of EHEC. EHEC is transmitted to humans primarily through consumption of contaminated foods, such as raw or undercooked ground meat products and raw milk.

4. Diseases Caused by EHEC
EHEC causes gastrointestinal complications:
Abdominal cramps
Diarrhea
Bloody diarrhea
Fever
Vomiting
EHEC incubation period: 3-4 days
EHEC Recovery period: within 10 days
World Health Organization. Escherichia Coli. Retrieved 07/23/
EHEC can cause a full range of gastrointestinal symptoms and discomforts. Abdominal discomforts and cramps are some of the common signs of infection. Patients with EHEC usually suffer form diarrhea. Sometimes the bacteria invade the mucosal layer of GI tract and cause bleeding of GI tract wall and therefore cause bloody diarrhea. Subsequently infection can enter the blood stream and cause fever. EHEC can also cause vomiting in some patients. The time interval between ingestion of the bacteria and onset of symptoms or the incubation period is usually 3-4 days. However, in some people it may take only one day or even10 days to show their symptoms. The symptoms start as mild as stomach pain or non-bloody diarrhea but worsen over several days. In most cases patients recover within ten days of infection.

5. Diseases Caused by EHEC
EHEC can cause Hemolytic Uremic Syndrome (HUS):
Acute renal failure
Hemolytic anemia
Thrombocytopenia
Population at risk: young children and the elderly
Morbidity: 5%-10%
Mortality: 3%-5%
World Health Organization. Escherichia Coli. Retrieved 07/23/
Unfortunately, EHEC could cause a life-threatening disease known as hemolytic uremic syndrome or HUS for short. HUS is an acute renal failure that can cause hemolytic anemia and thrombocytopenia. 5%-10% of patients particularly young children and the elderly who either have not developed a stronger immune system or have a compromised immune system respectively may develop HUS due to EHEC infection. People who develop HUS usually have a notable decrease in the frequency of urination. They constantly are feeling very tired and losing pink color in their cheeks and inside their lower eyelids. If someone develops HUS, he or she must immediately be hospitalized because his or her kidneys may stop working at any instance and cause other serious problems. However, if treated promptly and properly, most people with HUS recover within few weeks, but some people could suffer from permanent damage to their kidneys and even die due to kidney failure. About 3% to 5% of infective patients with HUS die from kidney failure.

6. Source of Infection The main reservoir of EHEC is cattle (CDC, 2011).
Transmission of EHEC to human is primarily through consumption of contaminated foods (WHO, 2011).
Cross-contamination during food cultivation, handling, and preparation is also common (WHO, 2011).
Person-to-person transmission is through oral-fecal route (CDC, 2011).
Center for Disease Control and Prevention. Escherichia coli O157:H7 and other Shiga toxin-producing Escherichia coli (STEC). Retrieved 07/23/
World Health Organization. Escherichia Coli. Retrieved 07/23/
Cattles are the main reservoir of the EHEC for human. However, other ruminants such as camel, goats, sheep, deer, and elk carry the bacteria in their guts and could potentially be the source of transmission. EHEC is transmitted to humans primarily through consumption of contaminated foods. Raw or undercooked ground meat products and raw unpasteurized milk are known to be a great source of EHEC bacteria. However, if water or any kinds of food get contaminated with fecal matter of ruminant animals or human, it could cause infection in individuals. In many places poor sanitation during food preparation with beef and other meat products can cause cross-contamination and lead to infection. Contaminated surfaces and kitchen utensils with EHEC are also considered as way of cross-contamination. Undercooked hamburgers, yogurt, cheese and milk are some food sources that are commonly reported as source of outbreak in recent years. Unfortunately, contamination is not limited to only meat and dairy products. Any food can get contaminated as it comes in contact with fecal matter of any source. In recent years there were an increasing number of outbreaks associated with the consumption of fruits and vegetables such as sprouts, lettuce, coleslaw, salad. These contaminations might be due to contact with feces from domestic or wild animals at some stage during cultivation or handling.
EHEC also can be transmitted from person-to-person contact. This mode of transmission is through the oral-fecal route. Infected person whether is showing clinical signs of infection or in carrier stage with no sign of sickness could infect other people through contact or cross contaminating. Although EHEC usually disappears from the feces of infected person by the time the illness is resolved, but sometimes individuals especially young children tend stay in carrier state for several weeks or even months.

7. Treatment Supportive therapy Hydration (WHO, 2011) No antibiotics
No help with the treatment
Increased Risk of HUS (CDC, 2011)
Center for Disease Control and Prevention. Escherichia coli O157:H7 and other Shiga toxin-producing Escherichia coli (STEC). Retrieved 07/23/
World Health Organization. Escherichia Coli. Retrieved 07/23/
Supportive therapy including hydration is the main treatment for the EHEC infection. Loss of water and electrolytes due to excess diarrhea and vomiting cause hypotension and electrolyte imbalance in the body. Intake of large amount of water and electrolytes could help alleviate the symptoms of vomiting and diarrhea such as dizziness and lightheadedness.
However, Antibiotic therapy shows no evidence that it could be helpful in treatment of EHEC. Taking antibiotics may increase the risk of HUS as well as any antidiarrheal agents like Imodium. Therefore, use of antibiotics is not recommended in case of EHEC infection.

8. Control and Prevention
Control measures at all stages of the food chain
Good hygienic slaughtering practices
Educating food handler
Bactericidal treatment
World Health Organization. Escherichia Coli. Retrieved 07/23/
In order to effectively prevent the contamination of food sources a control measures at all stages of the food chain is required. Food production, processing, manufacturing, as well as preparation whether at commercial setting or the domestic environment are the important steps that must be carefully monitored and specific intervention methods should put in place to reduce the incidence of EHEC in food supplies such as meat, dairies, and produce. For example a good hygienic slaughtering practices can greatly reduce contamination of carcasses by the animal’s fecal matter. Educating farm workers and food handlers in principles of good hygienic practice could help keeping contamination to the minimum. A bactericidal treatment such as heating by cooking or pasteurization or irradiation is some successful strategies that could eliminate EHEC from food supply.

9. Prevention
Proper hand washing before preparing and eating food (CDC, 2011)
Washing hands after animal contact (CDC, 2011)
Proper cooking of meat (CDC, 2011)
Pasteurizing dairy products and juices (CDC, 2011)
Washing fruits and vegetables (EPA, 2011)
Avoid swallowing water when swimming (EPA, 2011)
Prevent cross-contamination in food preparation (CDC, 2011)
Center for Disease Control and Prevention. Escherichia coli O157:H7 and other Shiga toxin-producing Escherichia coli (STEC). Retrieved 07/23/
United States Environmental Protection Agency. Basic Information about E. coli 0157:H7 in Drinking Water. Retrieved 07/23/
In every household proper hygiene is the key to prevent the infection with EHEC. In addition proper cooking and pasteurization practice could greatly help eliminating the bacteria from food sources. Here are some helpful tips to effectively prevent EHEC infection:
1.Washing hands thoroughly after using the bathroom before preparing or eating food.
2.Washing hands after contact with animals and pets or their environments at home, farms, zoos, fairs.
3.Cooking meats thoroughly up to the temperature of at least 160°F. It would be a good idea to use a thermometer, instead of relying on the color of the meat as an indicator.
4.Avoiding raw milk, unpasteurized dairy products, and unpasteurized juices like fresh apple cider.
5.Washing fruits and vegetables thoroughly, especially those that will not be cooked.
6.Avoid swallowing water when swimming or playing in lakes, ponds, streams, and swimming pools.
7.Prevent cross-contamination in food preparation areas by thoroughly washing hands, counters, cutting boards, and utensils after they touch raw meat.

10. References
Center for Disease Control and Prevention. Escherichia coli O157:H7 and other Shiga toxin-producing Escherichia coli (STEC). Retrieved 07/23/ oli_o157h7/#cause
United States Environmental Protection Agency. Basic Information about E. coli 0157:H7 in Drinking Water. Retrieved 07/23/ n/ecoli.cfm
World Health Organization. Escherichia Coli. Retrieved 07/23/ dex.html

11. Further Readings
World Health Organization. Food Standard Program. ftp://ftp.fao.org/codex/ccfh35/fh0305de.pdf
Brooks, J. T., E. G. Sowers, et al. (2005). "Non-O157 Shiga toxin– producing Escherichia coli infections in the United States, 1983–2002." Journal of Infectious Diseases 192(8):
Griffin, P. M. and R. V. Tauxe (1991). "The epidemiology of infections caused by Escherichia coli O 157: H 7, other enterohemorrhagic E. coli, and the associated hemolytic uremic syndrome." Epidemiologic Reviews 13: