The war against super bugs
Pastor Dale Morgan
The war against super bugs*
Last Updated February 17, 2007
CBC News
Every year, 250,000 Canadians pick up infections while they are in
hospitals being treated for something else. That's a staggering one out
of every nine Canadians who are admitted to hospital.
Every year, those infections kill more than 8,000 people.
That's more than will die of breast cancer, AIDS and car accidents
combined. Most of those deaths can be prevented — by simple hand washing.
In the wake of the SARS outbreak that hit Toronto in March 2003, hand
sanitizers have become common in hospitals and other public buildings
across the country. Many people use them — others don't.
A CBC-TV Marketplace investigation found that doctors often walk past
the sanitizers even while going from patient to patient. Dr. Michael
Gardam — the infection control expert at the University Health Network
in Toronto — says doctors are the least likely to wash their hands.
Many clean their hands only 10-20 per cent of the time.
"If you think about it, when I was a medical resident, nobody taught me
to wash my hands," Gardam said. "Nobody told me it was important. I'd
happily round on 30 patients and not wash my hands once because that was
the norm."
Microbes breed in hospitals, easily infecting people weakened by
illness. The most common bugs include:
MRSA
MRSA — methicillin-resistant Staphylococcus aureus — is a common
bacterium that has become resistant to certain types of antibiotics.
It's often found on the skin and in the noses of healthy people — and is
usually harmless. But it can cause infection if it gets into the body
through a cut or during surgery.
MRSA is usually transmitted to other patients through human hands,
especially the hands of healthcare workers, which have been contaminated
with MRSA bacteria by contact with infected or colonized patients. The
easiest way to prevent transmission is through hand washing with soap
and water or using an alcohol-based hand sanitizer.
When penicillin was first used, it was highly effective against
Staphylococcus aureus infections, but most strains of the bacterium are
now resistant to the antibiotic.
MRSA rarely infects healthy people, and is most often seen in hospitals.
The infection can develop in an open wound such as a bedsore or when
there is a tube such as a urinary catheter that enters the body. People
with long-term illnesses or who have compromised immune systems are at
increased risk of infection.
MRSA infections are treated with an antibiotic called vancomycin, which
is derived from soil bacteria found in India and Indonesia. Vancomycin
is extremely irritating to human tissue, so it is only used as a last
resort. Still, some bacteria have become resistant even to this
antibiotic, such as vancomycin-resistant Staphylococcus aureus (VRSA)
and [[vancomycin-resistant enterococcus]] (VRE).
A hospital patient who develops an MRSA infection can expect his or her
hospital stay to triple.
While MRSA outbreaks are fairly common in North America, some European
countries — including The Netherlands, Finland and Sweden — have been
very aggressive in dealing with the bacteria. The Netherlands has
adopted a "search-and-destroy" campaign: You're considered infected
until tests prove you're not. Infected people are put in isolation and
hand washing orders are enforced. Rates of infection have dropped
dramatically, even while they have remained higher in neighbouring
countries.
Vancomycin-resistant enterococci (VRE)
Enterococcus is a normally benign bacterium that lives in the intestine.
Enterococcus infections can occur in the urinary tract, in the blood and
in wounds, including surgical wounds.
While these infections can usually be treated with antibiotics such as
ampicillin and vancomycin, a strain that is resistant to both was first
discovered in France in 1986. Similar strains can now be found all over
the world.
Vancomycin-resistant enterococcus (VRE) is thought to be passed to
people through contact with animals or by eating meat. Once the meat is
eaten, the bacteria sit dormant in the person's gut until they come into
contact with an antibiotic. At that point the VRE can spread to the rest
of the body.
Since many patients in hospitals are put on some kind of antibiotic
therapy during the course of their treatment, VRE infections often occur
in hospitals.
"This organism is highly resistant," Gardam says. "It's resistant to
almost all the antibiotics that we use. We do a good job of cleaning the
room but if we miss part of the bedside table, a month later someone
touches it, they can get it. It's a very, very pervasive problem."
What are ESBL-producing bacteria?
ESBL stands for extended spectrum beta-lactamase, which are enzymes that
have developed a resistance to antibiotics like penicillin.
Enzymes are proteins produced by living organisms. The proteins speed up
biochemical reactions.
ESBL enzymes are most commonly produced by two bacteria – Escherichia
coli (otherwise known as E. coli) and Klebsiella pneumoniae. But ESBL
enzymes can also be found in bacteria such as Salmonella, Proteus,
Morganella, Enterobacter, Citrobacter, Serratia, and Pseudomonas.
In most cases, the body successfully fights off ESBL-producing bacteria.
However, because of the enzymes' ability to fight off antibiotics,
people with weak immune systems are at risk. This includes children, the
elderly and people with other illnesses.
ESBL-producing bacteria are spread through feces either by
self-infection or direct contact with feces of an infected person. It
can, for example, spread from patient to patient on the hands of
healthcare workers or the patients themselves. This is why hospitals and
seniors' homes are particularly prone to outbreaks.
Washing hands and anything else that comes into contact with an infected
person is important to preventing the spread of bacteria.
ESBL enzymes can also spread by passing from one bacterium to another.