Download Methicillin-Resistant Staphylococcus Aureus (MRSA)

Methicillin-Resistant
Staphylococcus Aureus
(MRSA)
What is it?
How did it get resistant?
Modes of transmission?
Environmental Sources?
Control Measures?
Proportion of S. aureus Nosocomial
Infections Resistant to Oxacillin (MRSA)
Among Intensive Care Unit Patients,
1989-2003*
Percent Resistance
70
60
50
40
30
20
10
0
1989 1991
1993
1995 1997
1999
2001 2003
Year
*Source: NNIS System, data for 2003 are incomplete
STAPHYLOCOCCUS AUREUS
• Staphylococcus
aureus, often
referred to simply
as "staph," are
bacteria
commonly carried
on the skin or in
the nose of
healthy people.
STAPHYLOCOCCUS AUREUS
Staph bacteria are one
of the most common
causes of skin
Infections. Most of
these infections are
minor (such as pimples
and boils) and most
can be treated without
Antibiotics. However,
staph bacteria can also
cause serious
Infections.
STAPH RESISTANCE
• Over the past 50 years,
treatment of these
infections has become more
difficult because Staph
bacteria have become
resistant to various
antibiotics, including the
commonly used penicillinrelated antibiotics. These
resistant bacteria are called
Methicillin-Resistant
Staphylococcus aureus, or
MRSA.
WHAT IS MRSA?
• MRSA is the term used for bacteria of the
Staphylococcus aureus group (S. aureus) that
are resistant to the usual antibiotics used in
the treatment of infections with such
organisms.
• Traditionally MRSA stood for methicillin
resistance but the term increasingly refers to
a multi-drug resistant group.
• Such bacteria often have resistance to many
antibiotics traditionally used against S.aureus.
HOW DOES IT GET RESISTANT?
• This resistance to methicillin is due to
the presence of the mec gene in the
bacteria.
• This alters the site at which methicillin
binds to kill the organism.
• Hence, methicillin is not able to
effectively bind to the bacteria.
MRSA COLONIZATION
• Colonization occurs when the
staph bacteria are present on or in
the body without causing illness.
• Approximately 25 to 30% of the
population is colonized in the nose
with staph bacteria at a given time
COLONIZATION WITH MRSA
• Most health professionals who are
colonized with MRSA do not develop
infection and many spontaneously clear
the organism without treatment.
• Once colonization has been present for
more than three months, it becomes
much more difficult to clear.
COLONIZATION AND INFECTION
• Infection occurs when the staph
bacteria cause disease in the person.
• Patients, however, have a 30-60% risk
of infection following colonization. This
is probably due to factors related to the
illness for which they are hospitalized,
which impair their ability to clear or
control colonization with the organism.
DECOLONIZATION AGENTS
FOR MRSA
•
•
•
•
•
Systemic
Vancomycin
TMP/SMX po
Rifampin po
Doxycycline po
Local
Chlorhexidine
body wash
Mupirocin ointment (Bactroban)
to the nares for 2
weeks
TYPES OF INFECTION STAPH
CAN CAUSE
• Staph bacteria can cause different kinds
of illness, including skin infections, bone
infections, pneumonia, severe lifethreatening bloodstream infections, and
others.
• Since MRSA is a staph bacterium, it can
cause the same kinds of infection as
staph in general
• However, MRSA occurs more commonly
among persons in hospitals and
healthcare facilities.
RISK FACTORS FOR MRSA
• Hospitalized patients
who undergo
surgery, the elderly
or very sick, an open
wound (such as a
bedsore) or a tube
inserted into their
body (such as a
urinary catheter or
intravenous [IV]
catheter)
RISK FACTORS FOR MRSA
• Certain factors can put some patients at
higher risk for MRSA including
prolonged hospital stay, receiving
broad-spectrum antibiotics, being
hospitalized in an intensive care or burn
unit, spending time close to other
patients with MRSA, having recent
surgery, or carrying MRSA in the nose
without developing illness
ENVIRONMENTAL MRSA
CONTAMINATION STUDIES
• 70% of rooms had environmental
contamination when the patient was
colonized or infected
• 42% of nurses’ gloves cultured were
contaminated after touching
environmental surfaces WITHOUT
touching the patient!
• Ref: Boyce, Infec Cont Hosp Epid 1977
ENVIRONMENTAL MRSA
CONTAMINATION STUDIES
• 7% stethoscopes were contaminated
with MRSA – wiping them with 70%
isopropyl alcohol significantly reduced
colony counts
• Contaminated surfaces include patient’s
gown, floor, bed linen, blood pressure
cuffs, overbed tables, stethoscopes,
pens, medical record
Bhalla A, et al. Acquisition of Nosocomial Pathogens on Hands After Contact
With Environmental Surfaces Near Hospitalized Patients. Infection Control and
Hospital Epidemiology 2004; 25:164-167.
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In this study they evaluated the frequency of acquisition of pathogens on hands
after contact with environmental surfaces near patients on 8 nursing units over a
2-week period. To assess the adequacy of hospital cleaning, specimens were
obtained from single-patient rooms that had been terminally cleaned using
standard housekeeping practices prior to admission of a new patient. For each
patient, investigators disinfected their hands with alcohol hand rub and imprinted
them onto blood agar plates. Then the same hand was placed onto the patient's
bedrail for 5 seconds and then onto the top of the bedside table for 5 seconds.
After the contact the fingertips and palm were imprinted onto agar plates.
Results showed all hands disinfected with alcohol hand rub were negative,
however, 53% of the hands which touched surfaces in an occupied room were
positive for pathogens and 24% were positive from a room that had just been
cleaned. Of concern was the observation that 35% of the cultures were positive
for MRSA. Gram negatives that were cultured included Acinetobacter, Klebsiella
and Enterobacter.
This study demonstrates the effectiveness of alcohol based hand rubs in
reducing the microbial load, the need for gloves when in precaution rooms
touching contaminated surfaces and the need for good housekeeping cleaning
procedures to remove pathogens from the environment.
ISOLATION GOWNS PREVENT
CONTAMINATION TO CLOTHES
AND HANDS
• Ref: Boyce, et. Al. SHEA 1998 Abstract
• 14 (40%) of 35 HCWs gowns were culture +
for MRSA on exiting room. Clothing
underneath was negative.
• 11 (69%) of 16 HCWs wearing freshly
laundered lab coats had detectable
contamination. 3 of 11 developed positive
hand cx after touching the coat.
Concerns about MRSA in
the future
• There is growing concern about MRSA
infections. They appear to be increasing in
frequency and displaying resistance to a
wider range of antibiotics.
• Of particular concern are the VISA strains of
MRSA (vancomycin intermediate susceptibility
S.aureus). These are beginning to develop
resistance to vancomycin, which is currently
the most effective antibiotic against MRSA.
Vancomycin-resistant
enterococci (VRE)
What is it?
How did it get resistant?
Modes of transmission?
Environmental Sources?
Control Measures?
Vancomycin-resistant
enterococci (VRE)
• Enterococci are
bacteria found in the
feces of most
humans and many
animals .
• There are two types of
enterococci associated
with normal healthy
people and which also
occasionally cause
human disease
Enterococcus Species
• They are called
Enterococcus faecalis
and Enterococcus
faecium.
• The commonest
infections caused by
enterococci are urinary
tract infections and
wound infections.
Enterococcus
• A variety of other
infections, including
infection of the blood
stream (bacteremia), heart
valves (endocarditis) and
the brain (meningitis) can
occur in severely ill patients
in hospital
ENTEROCOCCI
• Enterococci are a therapeutic
challenge because of their intrinsic
resistance to many antibiotics. Recent
reports of enterococci with high-level
resistance to multiple antibiotics have
highlighted the rapidly decreasing
therapeutic options for these
organisms. As we enter an era of
decreased antibiotic effectiveness, it
becomes more imperative to develop
appropriate infection control
procedures to decrease the
transmission of these organisms in
the health care setting.
What is VRE? Vancomycin
Resistant Enterococcus
• In 1986 the first vancomycin-resistant
enterococcus (VRE) was found in France and
a year later the first strain was isolated in the
UK. Similar strains have now been found
world-wide.
• 1989, the year VRE was first identified in the
United States, through 1993, the proportion
of enterococcal isolates resistant to
vancomycin reported to the National
Nosocomial Infections Surveillance System
increased 20-fold
HOW DOES IT GET RESISTANT?
• The genetic material which makes
enterococci resistant to vancomycin has
probably been passed on from other
types of bacteria that do not cause
human disease but which are already
vancomycin-resistant.
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The following agents have shown intrinsic resistance to
enterococci:
1.
Penicillin’s
2.
Cephalosporins
3.
Clindamycin
4.
Aminoglycosides
5.
Trimethoprim/sulfamethoxa-zole
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•
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The following agents have shown acquired resistance to
enterococci:
1.
Macrolides
2.
Tetracycline
3.
Lincosamides
4.
Chloramphenicol
5.
Aminoglycosides
6.
Penicillin (without beta-lactamase)
7.
Penicillin (with beta-lactamase)
8.
Vancomycin
•
9.
Quinolones
Source from Animals
• In a number of European countries, including
the UK, antibiotics related to vancomycin
such as avoparcin have been included in the
feed given to farm animals because they help
to improve meat yields.
• Animals and meat from farms where this
practice takes place have also been found to
have VRE indistinguishable from human
strains.
• VRE has been recovered from livestock feces
and from uncooked chicken
VRE ACQUISITION AND
COLONIZATION
• It is suspected that humans may acquire VRE
through contact with contaminated animals or
by eating their meat.
• The bacteria then reside harmlessly in the
patient's gut until the patient is admitted to
hospital.
• Here, due to the influence of antibiotic
therapy, VRE may spread from the gut and
cause an infection in another part of the
body.
COLONIZATION
WITH VRE
• At present VRE are common only in patients
who have been in hospitals for long periods,
those who have received certain antibiotics
(especially vancomycin, teicoplanin or
cephalosporins) and those who have been fed
by naso-gastric tube.
• However VRE are sometimes found in the
feces of people who have never been in
hospital or recently been given antibiotics.
• The elderly are particularly prone to
colonization with resistant organisms like VRE
Reservoirs Of VRE
• In normal healthy people illness due to
VRE is very rare, hence family members
and household contacts of patients with
VRE are not at any risk and normal
social hygiene should prevent them
acquiring the organism.
• Outbreaks within hospitals of VRE
infection have been reported mainly
from renal dialysis, transplant,
hematology, surgical and intensive care
units
Transmission and Acquisition of VRE
Environmental Sources of VRE
• Enterococci are also hardy organisms,
which allows them to survive well on
environmental surfaces.
• Resistant enterococci have been isolated
from surrounding areas of infected patients.
• Patient care equipment, such as electronic
thermometers, commodes, stethoscopes,
bedpans have been implicated in spreading
this organism.
MECHANISMS OF VRE
TRANSMISSION
• Contact spread is
the primary means
of transmission by
health care
workers. This
organism does not
spread via
respiratory
droplets.
TYPES OF DISEASES IT CAN CAUSE
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The types of diseases that
enterococci can produce are
as follows:
1.
urinary
2.
bacteremia/septicemia
3.
endocarditis
4.
intra-abdominal/pelvic
infections
5.
skin and soft tissue
6.
neonatal infections
7.
meningitis (rare)
8.
otitis media with effusion
9. llower respiratory (rare)
TRANSMISSION OF VRE
• Enterococci are
very tolerant
organisms and can
survive easily on
the hands of health
care personnel.
• Patient-to-patient
spread by health
care personnel has
been documented.
Clostridium difficile
What is it?
Modes of transmission?
Environmental Sources?
Control Measures?
Clostridium difficile
• C. difficile is a spore
forming bacteria which
can be part of the normal
intestinal flora in as
many as 50% of children
under age two, and less
frequently in individuals
over two years of age.
• C. difficile is the major
cause of pseudomembranous colitis and
antibiotic associated
diarrhea.
Clostridium difficile
• Clostridium difficile
is a Gram positive
anaerobic bacterium
that was first
described in 1935
when it was isolated
from stool samples
of new-born babies.
• It was not until the
mid 1970’s that it
became recognized
as a cause of
antibiotic-associated
diarrhea and colitis.
What are the risk factors for
C. difficile? • C. difficile-associated
disease occurs when the
normal intestinal flora is
altered, allowing C.
difficile to flourish in the
intestinal tract and
produce a toxin that
causes a watery diarrhea.
• Repeated enemas,
prolonged nasogastric
tube insertion and
gastrointestinal tract
surgery increase a
person's risk of developing
the disease.
What are the risk factors for
C. difficile?
• The overuse of antibiotics,
especially penicillin (ampicillin),
clindamycin and cephalosporins
may also alter the normal intestinal
flora and increase the risk of
developing C. difficile diarrhea.
What are the Symptoms of C.
difficile-associated disease?
• Mild cases of C. difficile disease are
characterized by frequent, foul smelling,
watery stools.
• More severe symptoms, indicative of
pseudomembranous colitis, include diarrhea
that contains blood and mucous, and
abdominal cramps.
• An abnormal heart rhythm may also occur.
How is C. difficile-associated
disease diagnosed?
• C. difficile diarrhea is
confirmed by the
presence of a toxin in a
stool specimen.
• A positive culture for C.
difficile without a toxin
assay is not sufficient
to make the diagnosis
of C. difficile.
• Endoscopic findings are
useful in diagnosis of
pseudomembranous
colitis.
Antidiarrheal Agents
• Antidiarrheal agents such as
Lomotil® or Imodium® have been
shown to increase the severity of
symptoms and should NOT be taken.
How can C. difficile-associated
disease be spread?
• Individuals with C. difficile-associated disease
shed spores in the stool that can be spread
from person to person.
• Spores can survive up to 70 days in the
environment and can be transported on the
hands of health care personnel who have
direct contact with infected patients or with
environmental surfaces (floors, bedpans,
toilets, electronic thermometers, etc.)
contaminated with C. difficile.
Transmission Factors
• An important characteristic of
• C. difficile-associated diarrhea and colitis is
its high prevalence among hospitalized
patients.
• Thus, C. difficile contributes significantly to
hospital length of stay, and may be
associated in some elderly adults with chronic
diarrhea, and occasionally other serious or
potentially life-threatening consequences.
Transmission
• One study demonstrated that
• 20% of patients admitted to a
• hospital for various reasons were either
positive for C. difficile on admission or
acquired the microorganism during
hospitalization.
• Interestingly, only one-third of these patients
developed diarrhea while the remainder were
asymptomatic carriers serving as a reservoir
of C. difficile infection.
Reservoirs
• The organism and its
spores were also
demonstrated in the
hospital environment,
including toilets,
telephones,
stethoscopes, bedpan
sanitizers, electroninc
thermometers, and
hands of healthcare
personnel.
Clinical Features
• Most cases develop 4 to 9 days after the
beginning of antibiotic intake.
• It should be noted, however, that some
patients develop diarrhea after antibiotics are
discontinued and this may lead to diagnostic
confusion.
• Although nearly all antibiotics have been
implicated with the disease, the commonest
antibiotics associated with C. difficile infection
are ampicillin, amoxicillin, cephalosporins,
and clindamycin.
Clinical Manifestation
• The most common presentation is either
mild colitis, or simple diarrhea that is watery
and contains mucus but not blood.
• Examination by sigmoidoscopy usually
reveals normal colonic tissue.
• General symptoms are commonly absent
and diarrhea usually stops when antibiotics
are discontinued.
Non-Specific Colitis
• C. difficile can also
cause non-specific
colitis quite
reminiscent of
other intestinal
bacterial infections
such as Shigella or
Campylobacter
• This is a more serious
illness than simple
antibiotic-associated
diarrhea; patients
experience watery
diarrhea 10 to 20
times a day and lower,
crampy abdominal
pain. Low-grade fever,
dehydration, and nonspecific colitis are
common
manifestations.
TYPES OF DISEASES IT CAN CAUSE
• The most serious
manifestation of C.
difficile infection,
fulminant colitis (severe
sudden inflammation of
the colon), is frequently
associated with very
serious complications.
This can be a lifethreatening form of C.
difficile infection and
occurs in 3% of patients
Laboratory Diagnosis
• The laboratory diagnosis of
C. difficile infection is
primarily related to the
demonstration of C. difficile
toxins in the stool of
suspected patients.
• The detection of C. difficile
toxins in the stool can be
made by a laboratory test
(cytotoxicity assay) where
the toxins can be easily
observed in the
microscope.
Laboratory Diagnosis of C. Difficile
• The tissue culture assay is considered the
gold standard because of its high sensitivity
and specificity.
• Since there is no correlation between levels
of C. difficile toxins in the stool and severity of
the disease, the results are reported simply
as "positive" or "negative." However, time is a
drawback of this assay since it requires 24 to
48 hours to read the results.
Categories of Precaution
Techniques
Standard
Contact
Droplet
Airborne
Standard Precautions
• Applies to everyone
• Hand washing
• Gloves, masks and gowns when deemed
necessary to protect you
• Cleaning patient care equipment between
patient use
• Environmental controls
• Careful handling of linen
• Appropriate patient placement
Precautions are used for both colonized and infected
patients
• Colonization:
The complex process of new organisms
becoming a part of the endogenous flora of
an area of the body with no signs of active
infection
Infection:
The presence of signs and symptoms of a
host/pathogen response (fever, drainage,
cough, purulence, inflammation, etc.)
Categories of Precautions Techniques
depend on modes of transmission
Modes of Transmission:
*Direct contact with blood and bodily fluids
*Indirect contact with contaminated items and
equipment
*Droplet
*Airborne route
Precaution Materials
*Precaution Gowns
*Vinyl Gloves
*Masks
*N95 Respirators
*Private Room
*Precaution Cart
*Signage
*Dedicated Equipment
(stethoscope, sphgmanometer)
*Cal Stat Alcohol Hand Rub
*Red Bags for Infectious Waste Disposal
Contact Precautions
Contact
- MRSA, VRE, C.Difficile, Abscess, Cellulitis,
Herpes Zoster, Impetigo, Staph aureus wound
infections, Streptococcus wound infections
Contact Precautions Techniques
• Gloves for
EVERYONE entering
the room – including
physicians, visitors,
family members
DIRECT TRANSMISSION FROM HANDS MOST
COMMON WAY DISEASE IS TRANSMITTED
•
You may not realize you
have germs on your hands!
Nurses, doctors and other
healthcare workers can
contaminate their hands by
doing simple tasks, including:
· taking a patient’s blood
pressure or pulse;
· assisting patients with
mobility;
· touching the patient’s gown
or bed sheets; and ·
touching equipment, including
bedside rails, over bed tables,
IV pumps.
The photo shows a blood agar
plate 24 hrs after an ICU nurse
placed her hand on plate”
Contact Precautions
• Gown if you will touch
or be close to the
patient’s bed (within 3
feet of the bed)
• Mask is only indicated if
you are likely to be
sprayed or splashed
during irrigation or
suctioning
Contact Precautions Techniques
• Contact Precautions:
•
Inside the Room:
• Covered linen hamper
• Red lined trash container
• Cal Stat Alcohol Hand Rub
• Stethoscope and Blood Pressure Equipment
• Disposable Thermometers
• Red Bags for disposal of contaminated
dressings and items used in patient care
Contact Precautions Techniques
• Outside the Room:
– Appropriate Sign in the Sign Holder
– Precaution Cart with gowns
– Contact Precautions Label on Medical
Record
– Glove boxes – 3 sizes (s, m, l) outside the
room
Contact Precautions – Dietary Trays
• Dietary will bring the food tray directly
into the room, wearing gloves
• Dietary will remove the tray wearing
gloves
• Trays DO NOT have to be bagged prior
to placement on the collection cart
• Precaution food trays will be cleaned in
the dishwasher
Contact Precautions – Transporting
the Patient
• Transport wears gloves and gowns while moving them onto
the stretcher/wheelchair
• They will cover the patient with a clean blanket or sheet to
confine and contain the contamination
• They will remove the gowns and gloves before transport to
prevent cross contamination
• They will wear gowns and gloves once arriving in the
receiving area while assisting with the transport
• Medical Record will be kept clean – bagging the chart is no
longer indicated
• Before transporting in a bed, the transporters will wipe the
siderails down with germicidal wipes.
Protocol to Discontinue Contact Prec.
for MRSA
• Three sets of negative surveillance cultures
from nares and
• One set of negative cultures from original
site of infection (urine, wound, g-tube,
sputum, etc.)
Contact – VRE
Vancomycin Resistant Enterococcus
• Enterococci are hardy organisms, which
allows them to survive well on
environmental surfaces.
• Resistant enterococci have been isolated
from surrounding areas of infected
patients.
• Patient care equipment, such as electronic
thermometers, commodes, stethoscopes,
bedpans have been implicated in
spreading this organism.
Contact - VRE
• Enterococci are
very tolerant
organisms and can
survive easily on
the hands of health
care personnel.
• Patient-to-patient
spread by health
care personnel has
been documented.
Protocol To Discontinue Contact for VRE
• Three sets of negative surveillance cultures
obtained one day apart when patient is off
antibiotics including:
• Rectal swab/stool culture
• Original site of infection – at least one
negative culture
Protocol to Discontinue Contact for
C. Dif. Precautions
• Asymptomatic – no diarrhea, cramping,
fever, no loose stools
• After an appropriate duration of
antibiotic treatment for 10-14 days.
Contact Precautions
• HIGH LEVEL DISINFECTION
• STAT III TB disinfectant must be used
to clean rooms, bedside equipment and
environmental surfaces.
• Bedside curtains are changed at time of
discharge
Alcohol Based Hand Rub
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“Evidence supports the belief that
improved hand hygiene can reduce
health-care associated infection rates.
Failure to perform appropriate hand
hygiene is considered the leading cause
of health-care associated infections and
spread of multiresistant organisms and
has been recognized as a substantial
contributor to outbreaks.” CDC
Guideline on Hand Hygiene
We recommend you use alcohol-based
hand rub (Cal Stat) for routinely
decontaminating hands:
1.
If hands are not visibly soiled.
2.
Before donning gloves prior to
insertion of invasive devices, e.g.
intravenous catheters.
3.
Before direct patient contact
4.
After contact with inanimate objects
5.
After removing gloves
6.
After direct patient contact
Banning Artificial Nails
•
•
•
Several studies have documented that
artificial nails worn by health care workers
(HCWs) can contribute to health careassociated infections. The CDC Guideline on
Hand Hygiene strongly recommends the
banning of artificial nails from direct and
indirect patient contact. Several welldesigned experimental, clinical, and
epidemiologic studies demonstrate
contamination risk from artificial nails.
This policy applies to providers of direct
patient care, those who would touch patients
in the course of providing care and to
providers of indirect patient care, those who
would touch critical items that would come in
contact with the patient (critical items include
but are not limited to medications, IV
solutions, blood products,
instruments/equipment for sterilization and
disinfection, food trays, and environmental
disinfection).