Our hospitals, clinics and nursing homes are being targeted by invisible enemies who kill and maim without remorse, without emotion or thought for humanity.  It is the "superbug" MRSA or methicillin-resistant Staphylococcus aureus supported by another enemy, Clostridium difficile aka C-Diff.

C-Difficile (Clostridium Difficile)

C. difficile is a bacterium of the family Clostridium, the same family also includes the bacteria that cause tetanus, botulism, and gas gangrene. It is an anaerobic bacterium. This means that it does not grow in the presence of oxygen.  It also produces spores that can survive for a long time in the environment without being noticed.

It usually lives is the large intestine, where there is very little oxygen. It can be found in small numbers in a low proportion of the healthy adult population. It is kept under control by the normal, 'good' bacterial population of the intestine. It is common in the intestine of babies and infants, but does not cause disease because its toxins do not damage their immature intestinal cells.

C. difficile causes diarrhoea, ranging from a mild disturbance to a very severe illness with ulceration and bleeding from the colon hence colitis and at it's worst, perforation of the intestine leading to peritonitis. It can be fatal.

Normally, it is only able to do this when the normal, healthy intestinal bacteria have been killed off by a course of antibiotics. When not held back by the normal bacteria, it multiplies in the intestine and produces two toxins that damage the cells lining the intestine. The result is then diarrhoea.

Patients who have been treated with broad spectrum type of antibiotics, ie; that affect a wide range of bacteria, including intestinal bacteria, are at the most risk of C. difficile. Most of those affected are elderly patients with serious underlying illnesses. Most infections occur in hospitals including local community hospitals, nursing homes, but it can also occur in primary care.

Some people can be healthy and carriers of C. difficile, but in most cases the disease develops after cross infection from another patient, either through direct patient to patient contact, via healthcare staff, or via a contaminated environment. A patient who has C. difficile diarrhoea excretes large numbers of the spores in their liquid faeces. These can contaminate the environment around the patient's bed, including surfaces, keypads, equipment, toilet areas, sluices, commodes, bed pan washers, etc. They can survive for a long time and be a source of hand-to-mouth infection for others.  If these patients have been on a course of antibiotics or the people in close contact with them have had recent or ongoing antibiotic treatment they are at risk of C-Difficile too.

C. difficile was first recognised to cause antibiotic-associated diarrhoea and colitis in the late 1970s, laboratory diagnosis was difficult and the number of cases was not monitored but as the years passed the voluntary system replaced with a mandatory reporting system.  Over one hundred types have been discovered but the most virulent type is 27.  This type of mutation which has neutralised the gene which resists toxin production is the one causing a larger proportion of the disease,  fatalities and is the one presently in the UK, Canada and North Eastern USA.

How  to prevent and control C. difficile.

More care in antibiotic prescribing to reduce the use of broad spectrum antibiotics by GP's and doctors.

1. Prioritise and speedily isolation of patients with diarrhoea from C-Difficile and excellent infection control from nursing staff.
2. Handwashing with anti-bacterial soap followed by alcohol gel.  Alcohol gel cannot be relied on as it does not kill the spores.
3. Staff and assistants wearing gloves and aprons, especially when dealing with bed pans and dirty linen etc.
4. Prudent environmental cleaning and use of a chlorine based (Hydrogen Peroxide) disinfectant where there are cases of C. difficile disease to reduce environmental contamination with the spores.
5. Visitors to the ward to ensure they wash hands thoroughly before leaving ward area and touchig other surfaces.

MRSA - Methicillin-Resistant Staphylococcus Aureus

  A term used to describe a number of strains of the bacteria, Staphylococcus aureus, that are resistant to a number of antibiotics, including methicillin.  Staphylococcus aureus is a group of bacteria that live on our  skin's surface and inside the nose. It is usually harmless. Most people who are carrying it are oblivious that they have it. It is thought that up to 30% of the general UK population carries these bacteria in their nose or on their skin.

Staphylococcus aureus is a very common cause of bacterial infections such as boils, carbuncles, infected wounds, deep abscesses and bloodstream infection (or bacteranemia). It was first described in the 1880s when doctors realised it was the most common cause of infected surgical wounds.

Virtually all strains of S. aureus were sensitive to penicillin when it was introduced in the 1940s. Before the development of penicillin these infections could cause serious or sometimes fatal disease. When penicillin was used to treat infections, some strains of S. aureus that were able to make an enzyme called penicillinase (that broke down the penicillin and protected the bacteria) became much more common. They had become resistant to the antibiotic.

Nosocomial infection is the term used for infection originating in hospital and is a major problem in many health care facilities, with approximately 1 in 10 patients acquiring an infection during a hospital stay. MRSA is now endemic in many hospitals, and is one of the leading causes of nosocomial pneumonia and surgical site infection and the second leading cause of nosocomial blood stream infections.

Cases of MRSA are now appearing in gyms and even schools,  medical staff in the USA report.  It's become as serious as Aids in the western world.

Who is most at risk?

People with weakened immune systems (for example due to other illnesses) or who have undergone surgery (for example heart surgery or hip replacement) can develop serious problems. Populations that are more susceptible to MRSA colonization, given other risk factors, include intravenous drug users, persons with dermatological diseases, or diabetes, and persons on renal dialysis.

What are the effects of MRSA?

MRSA may invade the blood and cause potentially serious complications such as bacteremia, septic shock, and serious metastatic infections (endocarditis, pneumonia, osteomyelitis, and arthritis). In more vulnerable people, Staphylococcus aureus bacteria have been known to cause boils, abscesses, impetigo, septic wounds, heart-valve problems and toxic shock syndrome. In extreme cases, it can result in death.

.Different types of infections

There is no specific 'MRSA disease' like with tuberculosis or typhoid. S.aureus infects a range of tissues and body systems (like those mentioned below) giving general often ambiguous symptoms that are common to different infections caused by other bacteria.

Wound infections
S.aureus / MRSA is the commonest cause of wound infection - either after accidental injury or surgery. This shows as a red, inflamed wound with yellow pus seeping from it. The wound may break open or fail to heal and a wound abscess could develop.

Superficial ulcers
Pressure ulcers, varicose ulcers and diabetic ulcers (all due to poor blood supply and superficial skin damage) are often sites of MRSA infection.

Intravenous line infections
MRSA may infect the entry site of an intravenous line causing local inflammation with pus from which the MRSA can enter the blood stream to cause a bacteraemia (blood stream infection).

Deep abscesses
If MRSA (or any S.aureus) spreads from a local site into the blood stream it can lodge at various sites in the body (e.g. lungs, kidneys, bones, liver, spleen) and cause one or more deep abscesses distant from the original site. These can be painful with high fever, a high white cell count in the blood and signs of inflammation near the infection. The patient will be very unwell and may have rigors (shivers) and low blood pressure (shock). Over a period, the body enters a catabolic state with breakdown of tissue, loss of weight and failure of essential organs. This is usually linked with an associated septicaemia.

Lung infections
MRSA / S.aureus is a rare cause of lung infection except in Intensive Care Units. There, the patient is on a ventilator with a tube in the trachea, bypassing the defences of the nose and throat. MRSA can gain entry to the lungs via the tube and cause pneumonia which may be fatal.

Bacteranemia / septicaemia

MRSA / S.aureus can enter the normally sterile blood stream either from a local site of infection (wound, ulcer, abscess) or via an intravenous catheter (placed there for their medical care). Bacteraemia describes the presence of MRSA / S.aureus in the blood. Septicaemia can follow and is the clinical term for a severe illness caused by the bacteria in the blood stream. The symptoms are not specific to MRSA and can be the same for other bacteria that cause septicaemia. Typically symptoms can include high fever; raised white cell count; rigors (shaking); disturbance of blood clotting with a tendency to bleed and failure of vital organs. This is the kind of MRSA infection that has the highest death rate.

Defence against MRSA

Good old fashioned soap and hot water - Good hygiene practices.  The bacteria live on our skin in our noses and normally harmless unless it is allowed to enter the blood stream.  The bacteria are intelligent and can verify which anti-biotics and drugs killed their brethren and mutate accordingly.  But researchers are now looking at drug and chemicals that will confuse the bacteria and therefore stop mutation.

Last update : 09-02-2008 20:31

Average user rating

No rating