Definition
There is no definition or even illness called E. Coli poisoning, but the
phrase is now used frequently in the mass media. It refers to a
particular complication of E. Coli food poisoning by E coli 0157, which
then causes further problems in the gut, blood and kidneys. These are
the complications that can occasionally, sadly, cause deaths following
food poisoning.
E Coli, or to give its full name Eschericia Coli, is one of the main
bugs that live in our gut and indeed has an important function in the
gut. As long as it stays in the gut it is harmless. However, there are
many different strains of E coli, several of which cause diarrhoea and
vomiting, food poisoning. ‘Uncomplicated’ food poisoning is the upset
stomach that mars many a foreign holiday, but clears up without
treatment in a day or so. Several bugs including E coli cause ‘Gippy
tummies’ and no specific treatment is needed other than to make sure
that your child is well hydrated and eventually the bug is eradicated
from the gut.
Symptoms
There are several types of E coli that cause diarrhoea and vomiting by
slightly different mechanisms. This particular type, Eschericia coil
0157, causes diarrhoea and vomiting but also produces a poison called
verotoxin. It is this toxin that causes the complications. Initially the
child has diarrhoea but the toxin causes damage to the gut lining so
the child begins to pass bloody diarrhoea. The toxin can easily pass
from the gut into the body where it attacks both the blood and kidneys
producing a very sick child who is pale, sweating and may not be fully
conscious.
Complications
The toxin destroys the red blood cells (haemolytic) and may cause a
serious anaemia. The red cells carry oxygen to the cells of the body. If
there are fewer red cells in the blood stream then, in order to get the
same amount of oxygen to the cells the heart must pump the blood more
quickly. This can put a strain on the heart, which may be beating very
quickly. Despite the efforts of the heart the child may also have a low
blood pressure, which actually reduces the ability of the blood to get
oxygen to the body’s cells.
The toxin also damages the kidneys, possibly by the fragments of the
damaged red cells clogging up the very small arteries in the kidneys
causing kidney failure (uraemic), hence the medical term
haemolytic-uraemic syndrome. Those people most at risk of developing
these complications are the very young and the very old.
Treatment
There is no specific treatment for this syndrome. The verotoxin has been
analysed, but there is no clinically effective anti-toxin, which can be
used like an antibiotic to reverse the complications. The mainstay of
treatment is to control the kidney failure. Fortunately in young
children this type of sudden kidney failure usually improves by itself
with time so the doctors have to make sure that they control the
complications of kidney failure. The anaemia may be severe and blood
transfusions might be used. However, transfusions must be used with care
as the verotoxin still in the body can destroy the transfused red cells
worsening the problem. In very severe cases plasmapheresis can be used.
This is a sort of washing of the red cells when the child’s plasma,
liquid part of the blood, is exchanged for fresh plasma.
Outcome
The vast majority of children with E coli poisoning make a full recovery
although they may require intensive medical help. A few have some
degree of continuing kidney damage. Tragically, a very very few cannot
be saved. In the recent outbreaks it has been the elderly who have been
most at risk of
dying.
Prevention
The most effective method of preventing infection with E coli is by
careful hand washing with normal soap and water before handling or
eating food. This will stop the spread of any E coli from the hands to
food. However, the most recent worst outbrea