WHAT IS E-COLI ?

WHAT IS E COLI?

           E. coli is short for Escherichia coli. It is a type of bacteria present in the gut of humans and other animals. Most strains are harmless but some are able to produce toxins that can cause symptoms such as severe cramps and diarrhoea. The World Health Organization says the E. coli is a completely new strain of bacteria. Researchers in China say preliminary genetic analysis of the outbreak suggests the bacteria is unique They say it has genes from two distinct groups of E. coli: enteroaggregative E. coli (EAEC) and enterohemorrhagic E. coli (EHEC).

             The outbreak is causing severe infections and in a number of cases, affecting the blood and kidneys. Haemolytic uraemic syndrome - an unusual complication of some types of E. coli as well as other infections - has been seen in hundreds of current cases.Symptoms include bloody diarrhoea and fevers. Epileptic fits can occur in severe cases. Haemolytic uraemic syndrome can be fatal and can sometimes lead to chronic kidney problems in later life.

E.coli bacteria

                    The exact source of the contamination has not yet been determined. Until the cause is known, German officials are telling people to avoid eating raw tomatoes, cucumbers and leafy salad including lettuce, especially in the north of the country, until further notice. The UK's Health Protection Agency recommends travellers follow the same advice. It says anyone returning from Germany with illness including bloody diarrhoea should seek urgent medical attention and mention their travel history.There have been seven cases in the UK.

• Processed meats: hamburgers, kebabs and salami
• Cheese, milk, butter, yoghurt, ice cream and other dairy products
• Salad vegetables such as coleslaw, lettuce, spinach, radishes and alfafa sprouts
• Fruits including melons, grapes and apple juice
• Waterborne outbreaks associated with lakes, ponds, paddling and swimming pools

The Food Standards Agency in the UK has issued general advice on the need to wash fruit and vegetables.The agency says: "It's a good idea to wash fruit and vegetables before you eat them to ensure that they are clean, and to help remove germs that might be on the outside. "Peeling or cooking fruit and vegetables can also remove these germs."However, a Scottish expert said new research suggests washing alone may not be enough, as the bacteria may be inside the food.Dr Nicola Holden of The James Hutton Institute said: "The bacteria are able to get from animal sources on to crops through different routes, most likely in irrigation water or sometimes from slurry spraying, while some contamination can also occur during processing and packaging."She said the bacteria can colonise plant roots, moving up to the edible foliage or fruits."The threat to human health occurs because these bacteria are not simply sitting on the surface of the plant and are particularly difficult to remove post-harvest," she added.

What do other experts say?

Professor Brendan Wren from the London School of Hygiene & Tropical Medicine said E. coli can attach to the surface of fresh produce such as lettuce leaves, spinach leaves and cucumber. "These types of E.coli survive harsher environmental conditions than the typical E. coli and produce some nasty toxins to humans," he said. "They can survive in soil environments and fertiliser may be one source for the origin of the outbreak related to fresh produce such as cucumbers."Dr Jonathan Fletcher, senior lecturer in microbiology at the University of Bradford, said toxin-producing E. coli can cause very serious disease in humans, especially in the elderly or very young.Cattle seem to carry the toxin in their gut, without showing signs of illness, and it will be shed in the faeces."If cattle manure is used as a fertiliser, it is probable that vegetables such as cucumbers will be contaminated with E. coli, and if not washed properly it would be present in sufficient numbers to cause the infection."

           The source of this outbreak is believed to be contaminated salad vegetables. Initial reports that cucumbers were the source of the bacteria have not been confirmed and other food sources are being sampled. While E. coli infection is often caused by eating undercooked meat and eggs, there has been a recent rise in cases caused by fresh fruit and vegetables.They include foods that are eaten raw or only lightly cooked, such as salads, fresh fruit and bean sprouts. (Ref:BBC)

                                                                                                             Prof.John Kurakar

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