by Marco Torres
August 17, 2010
from
PreventDisease Website
Marco Torres
is a research specialist, writer and consumer advocate
for healthy lifestyles.
He holds degrees in
Public Health and Environmental Science and is a
professional speaker on topics such as disease
prevention, environmental toxins and health policy. |
2009 was the year of
the pandemic that never happened.
This year, a new drug-resistant
bacterial gene may accomplish what the H1N1 never could. Scientists
are warning that the super bug, an enzyme called New
Delhi-Metallo-1 (NDM-1),
could spread across the world as nothing has been able to treat it.
The
Lancet Infectious Diseases
reported that antibiotics have proved so far ineffective against the
bacterial gene, which was found in patients traveling to South Asia
for medical treatment. NDM-1 has been linked to the overuse of
antibiotics.
Lancet found that 37 Britons receiving
medical treatment in South Asia carried NDM-1 back with them to the
United Kingdom.
What is a
Superbug?
These are bacteria that have become resistant to the antibiotics -
perhaps the best known is
MRSA, Methicillin-resistant
Staphylococcus aureus, which no longer responds to the
antibiotic methicillin.
But how do they become resistant?
Bacteria are extremely adaptable and are able to mutate.
What happens when they're exposed to
antibiotics is that only the susceptible bacteria die - the bacteria
that are already resistant to the antibiotics live.
"The potential of NDM-1 to be a
worldwide public health problem is great, and coordinated
international surveillance is needed," Lancet wrote on its
website.
Dr David Livermore, one of the
researchers and who works for the UK's Health Protection Agency
(HPA), said:
"The NDM-1 problem is likely to get
progressively worse in the foreseeable future.
"The potential for wider international spread and for NDM-1 to
become endemic worldwide are clear and frightening."
Infections have already been passed from
patient to patient in UK hospitals. Researchers say the way to stop
NDM-1 is to identify and isolate any patients who are infected.
The spread of the drug-resistant bacterial gene could herald the end
of antibiotics, researchers warned.
"In many ways this is it," Tim Walsh
at Cardiff University, UK, told The Guardian newspaper. "This is
potentially the end."
The NDM-1 gene works by producing an
enzyme that safeguards bacteria against
β-lactam antibiotics, which
include penicillin.
These antibiotics have a ringed
structure which acts to halt the replication of bacteria. The enzyme
breaks this ring, rendering the drug ineffective. Other β-lactam
antibiotic-resistant bacteria have genes that work in the same way.
These infections are usually treated with
carbapenems - the "last resort"
antibiotics which have the broadest action and the lowest resistance
rates and tend to be used when all else fails. What's worrying
health professionals is that the NDM-1 is resistant to carbapenems,
too, and can be transferred between different bacteria.
Other bacteria have been known to produce similar enzymes, but only
a few UK cases have been resistant to carbapenems, and these have
not been able to transfer the resistance to other bacteria.
But carbapenem-resistant genes have been spreading elsewhere.
The 2009 case of a woman in Sweden with
a carbapenem-resistant infection picked up in India prompted the
UK's Health Protection Agency to issue a National Resistance Alert
at the beginning of last year. In it, the HPA warned of a slow
international accumulation of bacteria armed with the resistant
gene, listing spreads of infection in the USA, Israel, Greece and
Turkey.
And the gene is spreading in India, which some doctors think is
unsurprising.
"There is little drug control in
India and an irrational use of antibiotics," a
Delhi-based physician told the BBC.
The Indian health establishment has
since downplayed the report.
Karthikeyan Kumarasamy, lead
author of a March report in the Journal of the Association of
Physicians in India outlining the risks posed by NDM-1, now says
the warnings have been overblown.
"It's all hype and not as bad as it
sounds," Kumarasamy was quoted by India's Hindustan Times. "The
threat of the NDM-1 is not that big as, say, H1NI (swine flu),
the popular press has since deemed it."
"The conclusion that the bacteria was transmitted from India is
hypothetical. Unless we analyze samples from across the globe to
trace its origin, we can only speculate," he continued.
"If this emerging public health threat is ignored, sooner or
later the medical community could be confronted with carbapenem-resistant
(bacteria) that cause common infections, resulting in treatment
failures with substantial increases in health-care costs,"
Johann Pitout from the University of Calgary in Canada wrote in
a journal commentary.
Experts stress there is no need to
panic, as the number of cases is small.
However, the prospect of some infections
becoming untreatable by antibiotics is now becoming very real.
'Superbugs that we can't just cure
are not fiction any more. This will increasingly become the
reality,' warns Professor Enright.
'You would have to be very sick or unlucky to pick up an
untreatable bug - but if they become more common, we will have a
major problem on our hands.
Sources
Drug-Resistant Superbug
...Found in U.S. and Canada
September 14, 2010
from
PreventDisease Website
An infectious-disease nightmare is
unfolding:
Bacteria that have been made
resistant to nearly all antibiotics by an alarming new gene have
sickened people in three states and are popping up all over the
world, health officials recently reported.
The U.S. cases and two others in Canada
all involve people who had recently received medical care in India,
where the problem is widespread.
A British medical journal revealed the
risk last month in an article describing dozens of cases in Britain
in people who had gone to India for medical procedures. How many
deaths the gene may have caused is unknown; there is no central
tracking of such cases. So far, the gene has mostly been found in
bacteria that cause gut or urinary infections.
Scientists have long feared this - a very adaptable gene that
hitches onto many types of common germs and confers broad drug
resistance, creating dangerous "superbugs."
"It's a great concern," because drug
resistance has been rising and few new antibiotics are in
development, said Dr. M. Lindsay Grayson, director of
infectious diseases at the University of Melbourne in Australia.
"It's just a matter of time" until
the gene spreads more widely person-to-person, he said.
Grayson heads an American Society for
Microbiology conference in Boston, which was buzzing with
reports of the gene, called
NDM-1
and named for New Delhi. NDM-1 is an enzyme that makes bacteria
resistant to a broad range of
β-lactam antibiotics.
These include the antibiotics of the
carbapenem family, which are a mainstay for the treatment of
antibiotic-resistant bacterial infections.
-
On August 21, 2010 Ontario,
Canada had its first confirmed case of the "superbug" in
Brampton. There have been other confirmed cases in British
Columbia and Alberta.
-
On September 6, 2010 Japan
detected its first ever case of the NDM-1 enzyme.
-
In May 2009, a Japanese man in
his 50's who had recently returned from holidaying in India
was struck with a fever and hospitalized, later making a
full recovery. Hospital officials have confirmed that tests
carried out after the patients recovery were positive for
the NDM-1 enzyme.
The U.S. cases occurred this year in
people from California, Massachusetts and Illinois, said Brandi
Limbago, a lab chief at the Centers for Disease Control and
Prevention (CDC).
Three types of bacteria were involved,
and three different mechanisms let the gene become part of them.
"We want physicians to look for it,"
especially in patients who have traveled recently to India or
Pakistan, she said.
What can people do?
Don't add to the drug resistance problem, experts say. Don't
pressure your doctors for antibiotics if they say they aren't
needed, use the ones you are given properly, and try to avoid
infections by washing your hands.
The gene is carried by bacteria that can spread hand-to-mouth, which
makes good hygiene very important.
It's also why health officials are so concerned about where the
threat is coming from, said Dr. Patrice Nordmann, a
microbiology professor at South-Paris Medical School.
India is an overpopulated country that
overuses antibiotics and has widespread diarrheal disease and many
people without clean water.
"The ingredients are there" for
widespread transmission, he said. "It's going to spread by plane
all over the world."
The U.S. patients were not related.
The California woman needed hospital
care after being in a car accident in India. The Illinois man had
pre-existing medical problems and a urinary catheter, and is thought
to have contracted an infection with the gene while traveling in
India. The case from Massachusetts involved a woman from India who
had surgery and chemotherapy for cancer there and then traveled to
the U.S.
Lab tests showed their germs were not killed by the types of drugs
normally used to treat drug-resistant infections, including,
"the last-resort class of
antibiotics that physicians go to," Limbago said.
She did not know how the three patients
were treated, but all survived.
Doctors have tried treating some of these cases with combinations of
antibiotics, hoping that will be more effective than individual ones
are. Some have resorted to using
polymyxins - antibiotics used in
the 1950s and '60s that were unpopular because they can harm
the kidneys.
The two Canadian cases were treated with a combination of
antibiotics, said Dr. Johann Pitout of the University of
Calgary in Alberta, Canada. One case was in Alberta, the other in
British Columbia.
Both patients had medical emergencies while traveling in India.
They developed urinary infections that were discovered to have the
resistance gene once they returned home to Canada, Pitout said.
The CDC advises any hospitals that find such cases to put the
patient in medical isolation, check the patient's close contacts for
possible infection, and look for more infections in the hospital.
Any case "should raise an alarm," Limbago said.
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