MRSA 'superbugs'
The number of MRSA deaths
doubled in four years between 1999 and 2003, official statistics show.
Ministers have set
ambitious targets to tackle the problem - and point to a significant
drop in infections during 2004, but the Tories say not enough is being
done.
What is MRSA?
Staphylococcus is a family
of common bacteria.
Many people naturally
carry it in their throats, and it can cause a mild infection in a
healthy patient.
MRSA stands for
methicillin-resistant Staphylococcus aureus, but is shorthand for any
strain of Staphylococcus bacteria which is resistant to one or more
conventional antibiotics.
Experts have so far
uncovered 17 strains of MRSA, with differing degrees of immunity to
the effects of various antibiotics.
Two particular strains,
clones 15 and 16, are thought to be more transmissible than the
others, and account for 96% of MRSA bloodstream infections in the UK.
At present, these strains are thought to be rare in other countries,
but are spreading.
Antibiotics are not
completely powerless against MRSA, but patients may require a much
higher dose over a much longer period, or the use of an alternative
antibiotic to which the bug has less resistance.
What are the symptoms?
MRSA infections can cause
a broad range of symptoms depending on the part of the body that is
infected. These may include surgical wounds, burns, catheter sites,
eye, skin and blood.
Infection often results in
redness, swelling and tenderness at the site of infection. Sometimes,
people may carry MRSA without having any symptoms.
Why does MRSA exist?
It's all about survival of
the fittest - the basic principle of evolution, and bacteria have been
around a lot longer than us, so they're pretty good at it.
There are countless
different strains of a single type of bacteria, and each has subtle
natural genetic mutations which make it different from the other.
In addition, bacterial
genes are constantly mutating.
Some strains' genetic
makeup will give them a slight advantage when it comes to fighting off
antibiotic attack.
So when weaker strains
encounter antibiotics, they die, while these naturally resistant
strains may prove harder to kill.
This means that next time
you encounter Staph, it is more likely to be one which has survived an
antibiotic encounter, ie a resistant one.
The advice from doctors
who give you antibiotics is always to finish the entire course -
advice which many of us ignore.
When you don't finish the
course, there's a chance that you'll kill most of the bugs, but not
all of them - and the ones that survive are of course likely to be
those that are most resistant to antibiotics.
Over time, the bulk of the
Staph strains will carry resistance genes, and further mutations may
only add to their survival ability.
Strains that manage to
carry two or three resistance genes will have extraordinary powers of
resistance to antibiotics.
The reason that hospitals
seem to be hotbeds for resistant MRSA is because so many different
strains are being thrown together with so many doses of antibiotics,
vastly accelerating this natural selection process.
Why is it so dangerous?
It is a fact of life in
the NHS that patients are at higher than normal risk of picking up a
Staph infection on the wards.
This is for two reasons -
firstly, that the population in hospitals tends to be older, sicker
and weaker than the general population, making them more vulnerable to
the infection.
Secondly, conditions in
hospitals, which involve a great many people living cheek by jowl,
examined by doctors and nurses who have just touched other patients,
are the perfect environment for the transmission of all manner of
infections.
Staph infections can be
dangerous in weakened patients, particularly if they can't be cleared
up quickly with antibiotic treatments.
MRSA infections can prove
tough to treat because they are resistant to treatment, making them
more dangerous than a simple case of Staph.
What is likely to
happen in the future?
Doctors are very worried
about what the future holds for MRSA.
The number of reports of
MRSA infections rises year by year - and the latest evidence suggests
that deaths due to MRSA are increasing at a similar rate.
Already, the spectre of a
bug resistant to all antibiotics is approaching.
VRSA, or vancomycin
resistant Staphylococcus Aureus, has acquired resistance to a drug
considered the "last line of defence" when all other antibiotics have
failed.
The UK has already seen
several cases of GISA, or glycopeptide intermediate Staphylococcus
aureus, a kind of "halfway house" between MRSA and VRSA, which has
developed a resistance to antibiotics of the vancomycin family.
Although new antibiotics
are being developed all the time, pessimistic experts believe it is
only a matter of time at current rates until virtually every weapon in
the pharmaceutical arsenal is nullified.
Nihilists suggest that
there could come a point at which bacteria retake the upper hand, and
doctors, as in previous centuries, have no answer to some bacterial
infections.
It should be noted, they
say, that humans have only had the upper hand over bacteria for a
handful of decades - we have no right to expect that situation to last
forever.
What can we do about it
now?
The government is already
trying to at least slow down the apparently relentless march of the
bacteria.
One of the main reasons
behind their swift evolution into "superbugs" is the overuse of
antibiotics, both in human and veterinary medicine.
Until recently, patients
visiting their doctor with a viral infection might demand, and be
given an antibiotic prescription - despite the fact that antibiotics
have no effect on this.
All those patients were
doing was strengthening the communities of bacteria in their bodies.
Doctors have now been told
to cut antibiotic prescribing.
Hygiene is another tried
and tested way of at least protecting the most vulnerable patients
from the most dangerous strains.
Handwashing between
patients should be a must for doctors and nurses, or they are simply
doing more harm than good in their trips around the wards.
Ministers are trying to
improve overall standards of hygiene, perhaps by reintroducing the
concept of the ward matron, with responsibility for cleanliness.
New patient bedside phones
are being introduced that include speed dial buttons to alert staff to
the need to deal with a hygiene problem
Whether a dirty ward
rather than a dirty hand is a reservoir for Staphylococcus is a matter
of debate.
But MRSA patients are also
increasingly being treated in isolation where possible.
In the long run, many
experts suggest it may take a breakthrough akin to the discovery of
penicillin before humans can regain a temporary upper hand over the
bugs again
|