Transcript Methicillin-resistant Staphylococcus aureus

MRSA… review
• Methicillin-resistant Staphylococcus aureus (MRSA) are isolates
of the bacterium Staphylococcus aureus that have acquired genes
encoding antibiotic resistance to all penicillins, including methicillin
and other narrow-spectrum β-lactamase-resistant penicillin
antibiotics.[1] The first MRSA was discovered in the UK in 1961, but
MRSA are now widespread in the hospital setting. MRSA is
commonly termed a superbug.
• MRSA may also be known as oxacillin-resistant Staphylococcus
aureus (ORSA) and multiple-resistant Staphylococcus aureus,
while non-methicillin resistant strains of S. aureus are sometimes
called methicillin-susceptible Staphylococcus aureus (MSSA) if
an explicit distinction must be made.
• Although MRSA has traditionally been seen as a hospital-associated
infection, community-acquired MRSA strains have appeared in
recent years, notably in the U.S. and Australia.[2] The abbreviations
CA-MRSA (community-associated MRSA) and HA-MRSA (hospitalassociated MRSA) are now commonly seen in medical literature.
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Staph superbug may be infecting patients
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June 25, 2007 07:27:23 PM PST
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A dangerous, drug-resistant staph germ may be infecting as many as 5 percent of hospital and nursing home patients,
according to a comprehensive study.
At least 30,000 U.S. hospital patients may have the superbug at any given time, according to a survey released Monday by the
Association for Professionals in Infection Control and Epidemiology.
The estimate is about 10 times the rate that some health officials had previously estimated.
Some federal health officials said they had not seen the study and could not comment on its methodology or its prevalence. But
they welcomed added attention to the problem.
"This is a welcome piece of information that emphasizes that this is a huge problem in health care facilities, and more needs to
done to prevent it," said Dr. John Jernigan, an epidemiologist with the U.S. Centers for Disease Control and Prevention.
At issue is a superbug known as Methicillin-resistant Staphylococcus aureus, which cannot be tamed by certain common
antibiotics. It is associated with sometimes-horrific skin infections, but it also causes blood infections, pneumonia and other
illnesses.
The potentially fatal germ, which is spread by touch, typically thrives in health care settings where people have open wounds.
But in recent years, "community-associated" outbreaks have occurred among prisoners, children and athletes, with the germ
spreading through skin contact or shared items such as towels.
Past studies have looked at how common the superbug is in specific patient groups, such as emergency-room patients with
skin infections in 11 U.S. cities, dialysis patients or those admitted to intensive care units in a sample of a few hundred teaching
hospitals.
It's difficult to compare prevalence estimates from the different studies, experts said, but the new study suggests the superbug
is eight to 11 times more common than some other studies have concluded.
The new study was different in that it sampled a larger and more diverse set of health care facilities. It also was more recent
than other studies, and it counted cases in which the bacterium was merely present in a patient and not necessarily causing
disease.
The infection control professionals' association sent surveys to its more than 11,000 members and asked them to pick one day
from Oct. 1 to Nov. 10, 2006, to count cases of the infection. They were to turn in the number of all the patients in their health
care facilities who were identified through test results as infected or colonized with the superbug.
The final results represented 1,237 hospitals and nursing homes — or roughly 21 percent of U.S. inpatient health care facilities,
association officials said.
The researchers concluded that at least 46 out of every 1,000 patients had the bug.
There was a breakdown: About 34 per 1,000 were infected with the superbug, meaning they had skin or blood infections or
some other clinical symptom. And 12 per 1,000 were "colonized," meaning they had the bug but no illness.
Most of the patients were identified within 48 hours of hospital admission, which means, the researchers believe, that they
didn't have time to become infected to the degree that a test would show it. For that reason, the researchers concluded that
about 75 percent of patients walked into the hospitals and nursing homes already carrying the bug.
"They acquired it in a previous stay in health care facility, or out in the community," said Dr. William Jarvis, a consulting
epidemiologist and former CDC officials who led the study.
The infection can be treated with other antibiotics. Health care workers can prevent spread of the bug through hand-washing
and equipment decontamination, and by wearing gloves and gowns and by separating infected people from other patients.
The study is being presented this week at the association's annual meeting in San Jose, Calif., but has not been submitted for
publication in a peer-reviewed medical journal.
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HANDWASHING!!!!
THE 2006 CAMPAIGN; In Clean Politics, Flesh Is
Pressed, Then Sanitized
By MARK LEIBOVICH
The New York Times October 28, 2006
Campaigns are filthy. Not only in terms of last-minute smears and dirty tricks.
But also as in germs, parasites and all the bacterial unpleasantness that is
spread around through so much glad-handing and flesh-pressing.
''You can't always get to a sink to wash your hands,'' said Anne Ryun, wife of
Representative Jim Ryun, Republican of Kansas.
Hands would be the untidy appendages that transmit infectious disease.
Like so many other people involved in politics these days, Mrs. Ryun has
become obsessive about using hand sanitizer and ensuring that others do, too.
She squirted Purell, the antiseptic goop of choice on the stump and selfproclaimed killer of ''99.99 percent of most common germs that may cause
illness,'' on people lined up to meet Vice President Dick Cheney this month at a
fund-raiser in Topeka.
When Mr. Cheney was done meeting and greeting, he, too, rubbed his hands
vigorously with the stuff, dispensed in dollops by an aide when the vice
president was out of public view.
That has become routine in this peak season of handshaking, practiced by
everyone from the most powerful leaders to the lowliest hopefuls. Politics is
personal at all levels, and germs do not discriminate. Like chicken dinners and
lobbyists, they afflict Democrats and Republicans alike. It would be difficult to
find an entourage that does not have at least one aide packing Purell.
Mysophobia
An abnormal fear of dirt or
contamination
• Compulsive hand-washing
• Anxiety over disorganization, sloppiness or
lack of control
Use of Alcohol…
• 70% ethanol
• Alcohol doesn't cut through grime well, so
dirt, blood, feces or other body fluids or
soil must be wiped or washed away first, if
the alcohol in the sanitizer is to be
effective. In such cases, hand washing
with soap and water is advised.
Dr. Levy Says….
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Dr. Levy wrote: ''Bacteria are a natural, and needed, part of life. Most live blamelessly.
In fact, they often protect us from disease because they compete with, and thus limit
the proliferation of, pathogenic bacteria. The benign competitors can be important
allies in the fight against antibiotic-resistant pathogens.''
In making a case against products spiked with antibacterials, he explained: ''Like
antibiotics, antibacterials can alter the mix of bacteria; they simultaneously kill
susceptible bacteria and promote the growth of resistant strains. These resistant
microbes may include bacteria that were present from the start. But they can also
include ones that were unable to gain a foothold previously and are now able to thrive
thanks to the destruction of competing microbes.''
Given the chance to proliferate, some of these emergent organisms ''may become
new agents of disease,'' Dr. Levy said.
The most frequently used antibacterial agent in consumer products is triclosan. Laura
McMurry and colleagues in Dr. Levy's laboratory have shown that while triclosan
wipes out the most sensitive bacteria, it also gives rise to bacteria that resist its action
by pumping the chemical out of their cells.
''Residues are the potential problem,'' Dr. Levy said. ''We're talking about chemicals
that can stick around in the home and continue to select for resistance when the
levels of these chemicals drop. Then even high levels of the chemicals won't work.''
Another potential problem of creating a superhygienic environment is
misdevelopment of the immune system in children that persists throughout life. The
developing immune system may need to be primed to function properly.
Handwashing…
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*Always wash your hands with soap and water after using the toilet, before preparing
or eating food, after working in the garden or changing a dirty diaper.
*Thoroughly rinse under running water all fruits and vegetables before eating or
preparing them, including foods like melons and grapefruit. Skins can harbor diseasecausing microorganisms that contaminate the edible part of the food, especially if it
sits around unrefrigerated for a while.
*Always thaw foods in the refrigerator. Do not leave cooked foods unrefrigerated for
more than two hours, or for more than one hour when the temperature reaches 90.
*Use separate cutting boards for uncooked meat, poultry or fish, and for vegetables,
fruits and bread. Always wash surfaces, including the sink, and utensils that have
been in contact with raw meat, poultry, fish or eggs with hot soapy water as soon as
you are through using them.
*Plastic cutting boards, sponges and dishcloths can be sanitized in the dishwasher.
*To sanitize a surface or object, use bleach, denatured alcohol or hydrogen peroxide.
These do their work and disappear, leaving no residue to foster microbial resistance.
Laundry detergent with bleach is fine.
*Infant clothing, bedding, etc. might be washed separately from adult laundry, but no
special detergent is needed. If you use cloth diapers, they should always be washed
separately in hot water with bleach.
*Close the lid on the toilet before you flush it to keep tiny droplets containing
microorganisms from spewing into the air.
The rules change if someone in the household is seriously ill or has a compromised
immune system. ''Products containing antibacterial agents are best reserved for use
when someone is very sick,'' Dr. Levy said. ''When caring for a sick person, hand
washing should should take more than one minute.''
How effective are antibacterial
soaps and hand sanitizers against
the viruses that cause “stomach
flu”?
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Handwashing is known to be one of the most effective ways to prevent the spread of germs and disease,
but how effective are popular antibacterial soaps and alcohol-based hand sanitizers against the germs
that are the most common cause of “stomach flu” ie. gastrointestinal illness characterized by nausea,
vomiting, diarrhea and abdominal pain? A team of researchers from Emory University and North Carolina
State University conducted a study to address this important public health question. Stomach flu is
usually caused by a group of viruses called “noroviruses”. The CDC estimates that these viruses are
responsible for about 23 million cases of stomach flu in the United States each year, and these viruses
have been associated with hundreds of outbreaks in nursing homes, schools and universities, childcare
centers, hospitals, cruise ships, hotels, summer camps and other settings where people are in close
contact and share living quarters or eat institutional or restaurant food. These viruses are spread by
ingestion of fecal-contaminated food or water, by person-to-person contact or contact with fecalcontaminated objects. Foodborne outbreaks usually involve food prepared by infected foodhandlers with
virus on their hands. Because these viruses are highly infectious, only a very small amount (about 2-10
virus particles) is enough to cause infection and illness. Careful and frequent handwashing is considered
to be a key public health barrier to prevent the spread of these infections.
In this study, a known amount of norovirus was placed on the fingers of volunteers and allowed to
dry. The investigators tested one common liquid antibacterial soap and one popular brand of an alcoholbased hand sanitizer to see how effective they were at removing the virus from the fingers compared to
rinsing with water only. They found that washing the fingers with plain water gave the greatest level of
norovirus reduction, with an average of about 96% removal. Washing the fingers with an antibacterial
liquid soap gave an average of about 88% removal. The alcohol-based sanitizer was not effective at
removing the virus from the volunteers’ fingers and only resulted in an average removal of 46%. This
study was a collaboration between Emory University and North Carolina State University and was funded
by a grant from the International Life Sciences Institute of North America (ILSI-NA). The experiments were
conducted by Dr. Pengbo Liu in the Hubert Department of Global Health at the Rollins School of Public
Health of Emory University. Dr. Liu presented his findings at the annual meeting of the American Society
for Microbiology in Orlando, FL on May 22, 2006.
These findings have important implications for healthcare settings, food service establishments,
childcare centers, schools and other venues that rely on alcohol-based hand sanitizers because of
convenience. These settings are at greatest risk of norovirus outbreaks because of frequent person-toperson contact and/or food preparation, and employees as well as residents in these settings need to
practice effective handwashing techniques. Although washing with plain water proved to be a successful
way to remove the norovirus from fingers, additional research is needed to develop hand sanitizers that
are effective against this group of viruses.