What is Enterohaemorrhagic E. coli (EHEC)?
Enterohaemorrhagic E. coli (EHEC) is a human pathogenic E. coli bacterium that is able to cause severe foodborne disease. EHEC is also known as shigatoxin-producing E. coli (STEC) or verocytotoxin-producing E. coli (VTEC). The incubation period is usually about 48-72 hours, but can range from 1-10 days. Symptoms may include abdominal cramps and bloody diarrhea; fever and vomiting may also occur. Most patients recover within 10 days but a few serious cases may be complicated with haemolytic uraemia syndrome (HUS), which is characterized by acute kidney failure, haemolytic anaemia and a low platelet count.
How are the bacteria transmitted to human?
EHEC is commonly found in the intestines and faeces of ruminants, such as cattle and sheep. Its transmission is mainly via the faecal/oral route, that is, food or water is directly or indirectly contaminated by ruminants’ faeces, which may then lead to infection in human through consumption of undercooked food or contaminated water, handling of contaminated food or contact with infected animals. Moreover, person-to-person transmission is possible among close contacts in families, childcare centres, nursing homes, etc. A very small number of EHEC bacteria are sufficient to cause infection in human. Examples of food that have previously been implicated in outbreaks of EHEC include undercooked beef and other meat products, unpasteurized milk, a variety of raw vegetables (such as cucumber, sprouts, spinach and lettuce), unpasteurized apple juice and cheese.
How to prevent getting EHEC infection?
Consumers can be exposed to EHEC infection mainly through consumption of contaminated food, in particular in raw or undercooked foodstuffs. And hence, measures to prevent EHEC infection are similar to those described in the WHO five keys to safer food; following good personal and food hygiene are particularly important.
Good Personal Hygiene
1. Wash hands thoroughly before handling food or eating; after using the toilet, changing of diapers, contact with animals or handling dirty things;
2. Wet hands with running water and apply liquid soap. Rub hands together to make a soapy lather and then rub the palms, backs of hands, between fingers, backs of fingers, thumbs, finger tips and wrists for at least 20 seconds. Rinse hands thoroughly under running water and dry hands.
Food Handling
1. Good personal and environmental hygiene prior to eating
l Wash hands with liquid soap and water before food handling or eating;
l Use clean cutlery or cooking utensils;
l Keep the kitchen and dining environment clean;
l Anyone with diarrhea or vomiting should stop handling food.
2. Avoid cross-contamination
l While shopping, keep raw food separate from other foods;
l Store ready-to-eat and cooked food above raw food in the refrigerator;
l Use separate utensils for handling raw and cooked food.
3. Cook thoroughly
l Cook all food thoroughly until the centre of the food reaches 75℃ or above;
l Meat, including minced meat, should be thoroughly cooked and the juices should run clear;
l Wash vegetables and fruits thoroughly. Skin should be peeled if they are consumed raw or used as salad ingredients;
l Cooked food should not be cooled and reheated more than once.
4. Keep food at safe temperatures
l Keep food at safe temperatures (below 5℃ or above 60℃);
l Do not leave cooked food at room temperature for more than 2 hours.
References
- WHO: Frequently asked questions on the EHEC infection outbreak in Germany.
- EFSA: Public health advice on prevention of diarrhoeal illness with special focus on Shiga toxin-producing Escherichia coli (STEC), also called verotoxin-producing E. coli (VTEC) or enterohaemorrhagic E. coli (EHEC).
