The presence of E. coli in water-cooler samples at eight railway stations has brought an uncomfortable public health question into focus: How safe is the water that passengers routinely drink while travelling? The finding comes from the Comptroller and Auditor General’s (CAG’s) latest audit of passenger amenities and sanitation at non-suburban railway stations.
The CAG also noted the presence of total coliform bacteria, including E. coli, in samples from taps at several stations in different years. The significance of the finding is not that every passenger drinking railway-station water will fall ill. “The presence of E. coli in drinking water is a warning sign because it can indicate faecal contamination and, therefore, a potential route for disease-causing organisms to enter the water supply. Most infections recover with supportive care, but bloody diarrhoea, severe abdominal pain, persistent vomiting, dehydration or reduced urine output should never be ignored,” says Dr Sanjay Verma, additional director, Internal Medicine, Fortis Hospital, Okhla.
E. coli, or Escherichia coli, is a group of bacteria that normally live in the intestines of humans and animals. Many strains are harmless and form part of the normal intestinal flora. The concern arises when disease-causing strains enter food or drinking water. This indicates contamination with faecal matter. It indicates that the water may not be safe for consumption and that the source of contamination needs to be identified and corrected. How would a person know if they have an E. coli infection?
There is no symptom that is exclusive to E. coli. The illness can initially resemble several other gastrointestinal infections, with diarrhoea, abdominal cramps, nausea and sometimes vomiting. In some cases the diarrhoea is watery, while infections caused by certain strains can produce bloody diarrhoea and marked abdominal pain. Blood in the stool is particularly important because it can occur with Shiga-toxin-producing E. coli, which damages the cells lining small blood vessels and can lead to serious complications. The condition can cause destruction of red blood cells and acute kidney injury.This is why an E. coli infection should not be viewed simply as a routine episode of diarrhoea. A patient who develops bloody diarrhoea, followed by increasing weakness, pallor, swelling or reduced urine output, needs prompt medical attention.
The initial injury occurs in the intestine, where disease-causing E. coli can attach to intestinal cells, produce toxins and cause inflammation. This produces the diarrhoea and abdominal symptoms. Then the Shiga toxin can cross into the bloodstream and affect small blood vessels in different organs. The kidneys are particularly vulnerable.
Damage to these vessels can contribute to the destruction of red blood cells and impaired kidney filtration. Reduced urine output is, therefore, an important warning sign after a diarrhoeal illness, particularly when it follows bloody diarrhoea.
No. The timing alone cannot establish the cause. Diarrhoea can be caused by a wide range of bacteria, viruses and parasites, and symptoms often overlap. Even if a person has consumed water from a source where E. coli was detected, that does not establish that the water caused their illness. If the illness is severe, persistent or associated with blood in the stool, a doctor may recommend laboratory testing rather than relying on symptoms alone.
The first step is a clinical assessment. Where the illness is severe, persistent or associated with bloody diarrhoea, stool testing may be advised. Depending on the circumstances, laboratories can use stool culture or molecular tests to identify E. coli. Testing for Shiga toxin or the genes responsible for producing it is particularly important.
A patient may also require blood tests to assess the blood count, electrolytes, hydration and kidney function. These investigations can help doctors identify complications such as anaemia or acute kidney injury.
Treatment depends on the particular strain and the patient’s clinical condition. Antibiotics are generally avoided in suspected Shiga-toxin-producing E. coli infections because, in some circumstances, they may increase the risk of kidney damage.
That does not mean antibiotics are never used for E. coli. Different E. coli infections have different clinical implications, and antimicrobial treatment should be decided by a doctor rather than being started by the patient on the basis of symptoms alone.
These medicines should also be used cautiously. A person should not self-medicate with anti-diarrhoeal drugs without medical advice. The immediate priority is to maintain hydration and assess whether the patient is developing complications. Simply suppressing diarrhoea is not always the appropriate goal.
There is no single E. coli test that determines whether someone needs an injection or an intravenous drug. The decision depends primarily on the patient’s clinical condition. Someone who is unable to maintain adequate fluid intake or has significant dehydration may require intravenous fluids. A seriously ill patient may need hospital monitoring and additional treatment depending on the complications.
The body’s clearance of the bacteria and recovery of the intestine are not necessarily simultaneous. In many uncomplicated infections, symptoms improve over several days as the immune system clears the organism. But the intestinal lining can remain inflamed for some time, which means loose stools, abdominal discomfort or altered bowel habits may persist even after the infection itself is resolving.
