Running head: HOSPITAL AND COMMUNITY ACQUIRED MRSA
Hospital and Community Acquired MRSA
Sandra Adrianne Pena
Concordia University
Fundamentals of Public Health
MPH 500
Dr. Jen Janousek
February 24, 2013
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Hospital and Community Acquired MRSA
Staph infections were first recognized as early as the 1880s, at that time many of the
antibiotics that we depend on today did not exist and there was little that could be done by
healthcare providers at the time to treat these oftentimes painful sores that could be located in
various areas on the body. Occasionally, these infections were known to rapidly progress to
various complications such as, bacterial pneumonia, sepsis, and sometimes even death
("NIAID," 2012). Roughly 60 years later, antibiotics like penicillin were discovered and they
were quickly proven to be invaluable in the treatment of various bacterial infections which
promptly lead to the overuse and misuse of antibiotics when they routinely began to be used for
the treatment of viral infections to which they had no benefit ("NIAID," 2012). The ramifications
of the misuse and over use of antibiotics rapidly led to antibiotic resistance which is the case
with MRSA. Methicillin-resistant Staphylococcus aureus also known as, MRSA is a, “infection
caused by a strain of staph bacteria that's become resistant to the antibiotics commonly used to
treat ordinary staph infections” ("Mayo Clinic," 2012). Because of this MRSA infections are
often referred to as a ‘super bug’.
Since it was first described in the early 1960s, “methicillin-resistant Staphylococcus
aureus (MRSA) has become a major public health issue because of worldwide spread of several
clones” (Laurent et al., 2012) that is affecting individuals all around the world.
Description
The microbiological appearance of the MRSA bacterium is, “spherical, gram-positive, and
contains a peptidoglycan layer in its cell wall, Staphylococcus aureus lacks flagella and as a
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result is non-motile” (Alexander, 2010). MRSA has the appearance of a ‘bunch of grapes’ under
the microscope due to the, “activity of the coagulase enzyme” ("bioquell.com", 2012).
Habitat
The natural habitat of S. epidermidis is, “protein-rich and warm, typically on catheters, surgical
wound, synthetic knees, hips or plates, and pins at fracture sites ("eHow," 2013) which are
common in the hospital setting. S. aureus thrives in the hospital setting and are extremely
virulent, resistant to most antibiotics and disinfectants” currently in use ("eHow," 2013). Staph is
also known to thrive in, “warm, moist places; common sites of colonization include the nostrils,
belly button, underarms, and groin” (“cdc.gov,” 2012) which are common in over populated
areas within the community.
Genetic Mechanism
Resistance of MRSA has been identified as having, “High-level resistance to methicillin [which]
is caused by the mecA gene, the presence of the mec gene is an absolute requirement for S.
aureus to express methicillin resistance (Lowy, 2013) which [then] encodes an alternative
penicillin-binding protein, PBP 2a” (Wielders, Fluit, Brisse, Verhoef, & Schmitz). “HA-MRSA
and CA-MRSA differ at the genetic level and have distinct biologic properties. These differences
suggest that CA-MRSA strains may spread more easily from person to person or cause more skin
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disease than HA-MRSA. At least three different strains of staph that causes CA-MRSA” (Baylor
College of Medicine, 2013). The mecA gene is part of a 21- to 60-kb Staphylococcal
Chromosome Cassette mec (SCCmec), a mobile genetic element that may also contain genetic
structures such as Tn554, pUB110, and pT181 which encode resistance to non-β-lactam
antibiotics” (Wielders et al.). “By using DNA microarray technology, mecA has been detected in
at least five divergent lineages, implying that horizontal mecA transfer has played a fundamental
role in the evolution of MRSA” (Wielders et al.)”.
Prevalence
The prevalence of MRSA in the community is predicted to increase substantially due to the
dissemination of a successful SCCmec type by horizontal transfer” (Wielders et al.). It is
estimated that, “1.5% of the U.S. population was colonized in the mose with S. Aureus and
MRSA respectively” ("cdc.gov," 2010). “The proportion of healthcare-associated staphylococcal
infections that are due to MRSA has been increasing 2% of S. aureus infections in U.S.
intensive-care units were MRSA in 1974, 22% in 1995, and 64% in 2004” ("cdc.gov," 2010).
With more that 14 million outpatient cases of S. aureus skin and soft tissue infections in the
community setting in 2005 alone the urgency for identifying effective treatment is rapidly
increasing ("cdc.gov," 2010). As HA and CA- MRSA continue to be studied many studies have
been completed one of which was by the association for Professionals in Infection Control and
Epidemiology which determined that, “70% of the isolates reported were likely to be HAMRSA, and approximately 30% were more consistent with CA-MRSA. Further stating, that
although CA-MRSA has received enormous recent media attention and the attention of many
researchers, HA-MRSA continues to account for the majority of the MRSA burden in US Health
care facility inpatient”(Jarvis, Schlosser, Chinn, Tweeten, & Jackson, 2007).
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Resistance
Many have questioned why MRSA has been able to take such an unforgiving hold on society and
affect and take so many lives and many believe that it is because the overuse of antibiotics.
Antibiotics have been hailed for the countless lives that have been saved over the last 70 years,
but resistance is becoming more and more common which is consequently affecting the way
patients with staph infections are being treated. A diagnosis of MRSA is made after an individual
does not respond to the first line antibiotic course that would normally treat and cure a staph
infection ("NIH," 2012). Antibiotics that MRSA is resistant now includes penicillin, this is
because, “Staphylococcus aureus can make a substance called ß-lactamase, that degrades
penicillin, destroying its antibacterial activity” (Johnson, 2007).As, “resistance to methicillin is
determined by the mecA gene, which encodes the low-affinity penicillin-binding protein PBP 2A.
This knowledge reinforces the belief that antibiotic resistance is due to the over use and misuse
of antibiotics has become a real problem that is currently lacking viable solutions to
[substantially] decrease the rate at which MRSA infections are occurring. This phenomenon of
antibiotic resistance is causing providers to get more aggressive and creative with the treatment
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of their patients leading to increased hospital stays and a general increase in hospital costs for
patients and insurers alike. The antibiotic treatment of MRSA falls heavily upon the use of
Penicillin and other –cillin drugs until like other drugs resistance was developed. Today,
“Vancomycin, teicoplanin and fosfomycin, and new MRSA-active antibiotics including
quinupristin/dalfopristin, linezolid and daptomycin. The most widely used of these
is Vancomycin, which is known as a glycopeptide antibiotic. Taken orally, Vancomycin only
works in the intestines to control infection there. For other areas of infection, Vancomycin must
be taken via injection. The drug is a rough ride. Symptoms of Vancomycin can include nausea,
dizziness, feeling cold, flushing, pain, muscle spasms, bruising, the development of a rash,
ringing in the ears, hearing difficulties, and breathing problems” (Kilham, C., 2012).
Staph infections are likely to occur in one of two environments: Hospitals and
communities:
Hospital Acquired (HA-MRSA)
Hospital acquired methicillin-resistant Staphylococcus aureus is where by far the most MRSA
vicious of the two infections are currently occurring. These infections are found in individuals
who have been in hospitals or other health care settings, when infection occurs in these settings,
it's known as, “health care-associated MRSA. HA-MRSA infections typically are associated with
invasive procedures or devices, such as surgeries, intravenous tubing or artificial joints ("Mayo
Clinic," 2012). Currently, the number of hospital acquired cases of MRSA vastly outnumbers the
number of community acquired cases.
Community Acquired (CA-MRSA)
The second location where MRSA has been identified is within the community and is referred to
as community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and is defined
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as, “a MRSA-positive specimen [that] was obtained outside the hospital setting or within two
days of hospital admission, and if it was from a person who had not been hospitalized within two
years before the date of MRSA isolation” ("CDC," 2012).Currently in the, “United States, it is
believed that 28% of community-acquired S. aureus strains are resistant to methicillin”
(Wielders et al.).
As agencies around the world continue to study various components of Staphylococcus
aureus (S. aureus) in attempts to find ways to decrease the current infection rates of S. aureus as
it is becoming an frighteningly common type of bacteria that is becoming increasingly difficult
to treat. In about, “one out of every four healthy people, the staph germ lives on the skin or in the
nasal passages, but it does not cause any problems or infections. These people are said to be
colonized with staph” ("Mayo Clinic," 2012). “Colonization is the presence of the bacteria, but
no acute signs of illness or infection” (Virginia Department of Health [VDH], 2012). In
approximately, “1-2 % of those who are colonized will proceed to infection; infection is the
clinical signs of illness or inflammation due to tissue damage caused by invasion by the bacteria.
Infection requires treatment” (VDH, 2012).
For many the initial presentation of MRSA is likely to begin as, “pustules or boils which
often are red, swollen, painful, or have pus or other drainage. They often first look like spider
bites or bumps that are red, swollen, and painful. These skin infections commonly occur at sites
of visible skin trauma, such as cuts and abrasions, and areas of the body covered by hair”
("CDC," 2012). Those that are diagnosed with this disease process are likely to experience a
gamete of other symptoms as well because symptoms vary depending on the type and stage at
which the infection is identified. With severe infections an individual may present with fever,
severe pain, abnormal blood counts, and/or foul odor at the infection site. It is advised that
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individuals seek medical care and treatment when individuals believe that a minor wound
becomes infected and it is firmly stated and reiterated that individuals not attempt to treat these
infections by themselves as it increases the possibility worsening an existing infection while
increasing the probability of spreading infections to other individuals. ("CDC," 2012)
As HA and CA-MRSA occur in different settings, “the risk factors for the two strains
differ” ("Mayo Clinic," 2012) as well.
Social and behavioral risk factors for HA-MRSA
Individuals are at an increased likelihood of developing a case of HA-MRSA are as expected
being hospitalized because individuals within hospitals have a tendency suppressed or
compromised immune systems. Additionally, those that have invasive medical device like
medical tubing such as intravenous lines or urinary catheters. Lastly, those who reside in long
term care facilities because MRSA is usually prevalent in these locations because of the presence
of both suppressed immune systems and the use of invasive medical devices ("NIH," 2012).
Risk factors for CA-MRSA
Include participation in contact sports such as football, basketball, and wrestling, since MRSA
can easily travel though cuts and abrasions that are likely to occur during contact sports. Also,
those living in crowded or unsanitary conditions like those common in military training camps
and jails have been linked to increased occurrence of MRSA. Lastly, it is thought that men who
engage in homosexual activities are at an increased risk of developing.
Prevention
As with all prevalent disease processes prevention is the number one factor that can make a
dramatic difference in these currently staggering statistics, if the overall incidence of infection
begins to decrease other complications associated with MRSA infections are likely decline as
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well including healthcare costs and mortality statistics. The prevention techniques that can be
used to combat the rising numbers of MRSA infections relies heavily on individuals maintaining
high levels of personal prevention practices which includes appropriate hand-washing
techniques, not sharing personal items like razors, keeping wounds clean and covered, and
avoiding contact with individuals that may have wounds or soiled bandages if appropriate
personal protective equipment is not available ("CDC," 2012). Other considerations should be
taken into account in specific locations when contacts with contaminated surfaces are more
likely. These specific locations include schools, athletic facilities, and correctional institutions.
The introduction of alcohol-based hand gels and sanitizers have been able to for improved hand
hygiene on-the-go. However, reducing the spread of MRSA within hospital settings has proven
to be quite difficult (Alexander, 2010).
Prevention has proven to be very useful in the efforts to combat the spread of MRSA, but
testing and diagnosis measures still remain essential as the first step utilized by healthcare
providers when determining what microorganism they are dealing with.
Diagnosis
Regardless of the strain MRSA diagnosis is made by checking a, “tissue sample or nasal
secretions for signs of drug-resistant bacteria” ("Mayo Clinic," 2012). After a sample is obtained
it is promptly sent to a laboratory where the sample can be placed in a, “dish of nutrients that
encourage bacterial growth” ("Mayo Clinic," 2012) but, for those samples to grow appropriately
they require a minimum of 48-hours, which could leave a critical patient in a very precarious
situation. Everyday newer methods are being identified to expedite the identification of MRSA
infections within patients; one of those methods is a, “test that can detect staph DNA in a matter
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of hours” ("Mayo Clinic," 2012) which is quickly gaining popularity in the medical community
nationwide.
It is estimated that, “MRSA is responsible 19,000 U.S. deaths and 368,000
hospitalizations per year” (Pew Health Group [PEW], n.d.). In the United States in 2003, there
were an estimated, “12 million doctor or emergency room visits for skin and soft tissue
infections suspected to be caused by Staph aureus” (Moore, 2013) which has encouraged the use
of antibiotics as the course of treatment leading to antibiotic use and misuse since. “In hospitals,
190 million doses of antibiotics are administered each day. Among non-hospitalized patients,
more that 133 million courses of antibiotics are prescribed by doctors each year. It is estimated
that 50 percent of the latter prescriptions are unnecessary” (American College of Physicians
[ACP], 2013). As the practice of prescribing unnecessary prescriptions has continued to raise
throughout the years the increasing number of patients being hospitalized with MRSA infections
has mirrored the lack of viable treatment options. In 2003, “about 21 out of every 1,000 patients
hospitalized to about 42 out of every 1,000 in 2008, or almost 1 in 20 inpatients” ("The
University of Chicago Press ," 2012). MRSA infections is an extremely concerning to patients,
healthcare providers, and insures alike as the “annual cost to treat patients with MRSA patient
are between $3.2 billion and $4.2 billion in the United States alone” (PEW, n.d.). It is estimated
that on average, [an] “uninsured family can only afford to pay in full for about 12% of any
hospitalizations they might experience (Assistant Secretary for Planning and Evaluation
[ASPE], 2011). Therefore those, “lacking health insurance poses a greater risk of financial
catastrophe than lacking car insurance or homeowner’s insurance” (ASPE, 2011) patients inside
and outside of hospitals and healthcare facilities alike when MRSA infections were at their peak.
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HOSPITAL STAYS WITH MRSA INFECTIONS
(1993–2005)
It is said tha the high costs associated with MRSA infections, both monatary and
emotinally should be more than enough to instate stringent infection control programs within
healthcare facilites that will aid in combating the rising numbers of hospital aquired cases of
infectious diseases (Hannah, 2005). As the number of cases of HA-MRSA increased agressive
hand-washing and gel-in/gel-out programs have been instated in healthcare facilities around the
country consequently leading to an increase in, “Hand hygiene compliance rates from a baseline
compliance of 49% to 98%”, therefore the improvements in hand hygiene compliance among
patients, visitors, and staff has translated into a notable decrease in the number of hospitalacquired MRSA infections as statistics showed that the number of hospital acquired infections
went from, “0.52 per 1,000 patient days in 2005 to 0.24 per 1,000 patient days by year-end 2008”
(Lederer Jr, Best, & Hendrix, 2009).
With heightened awareness about the increasing commonness of HA and CA-MRSA
everyone is making increased efforts to clean and sanitize areas that are likely to have been
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contaminated by MRSA organisms. Cleaners that are used to remove dirt and germs from
surfaces by rinsing them away with the routine cleaning of the surfaces are marginally effective.
Also, sanitizers that reduce germs on surfaces, like hands are very effective, but do not
completely get rid of germs. Lastly, disinfectants which are chemical products that are used to
destroy or inactivate germs consequently, preventing them from growing further are regulated by
various agencies but are common for use on inanimate objects and surfaces that are visibly soiled
with blood or other secretions ("CDC," 2012)
As the spread of MRSA initially skyrocketed, then tapered slightly, before finally starting
to decrease to some degree it is apparent that progress is being made. These victories can only be
attributed to diligence by healthcare workers to abide by infection control guidelines and policies
and by the educational efforts that continue to be made by health educators and providers and
lastly credible information that is constantly being provided and updated by governmental
agencies like The Centers for Disease Control and Prevention (CDC) and the National Institute
of Health (NIH).
Development of antibiotic resistance
In the late 1940s, “medical treatment for S. aureus infections became routine and
successful with the discovery and introduction of antibiotic medicine, such as penicillin”
("NIAID," 2012). From that point on, however, use of antibiotics began to be taken for granted
and subsequently used for a gamete of conditions to which antibiotics proved to be ineffective.
The reoccurrence of misuse lead to bacterial evolution which assisted, “the microbes to become
resistant to drugs designed to help fight these infections” ("NIAID," 2012). The first line of
drugs that S. aureus developed resistance to was penicillin. Methicillin, a form of penicillin, was
introduced to counter the increasing problem of penicillin-resistant S. aureus. Methicillin was
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one of the most common types of antibiotics used to treat S. aureus infections; but, in 1961 the
first strains of S. aureus bacteria that resisted methicillin was discovered leading to the birth of
MRSA. It took nearly seven years for the first reported case of MRSA in the United States and
from that many other new and increasingly resistant strains are emerging. MRSA is actually
Resistant to an entire class of penicillin-like antibiotics that includes penicillin, amoxicillin,
methicillin, and other –illin drugs ("NIAID," 2012). With resistance developing against many illin drugs , this caused physicians to begin to rely heavily on vancomycin which is classified as
a last resort drug of sorts because it is known to kill everything, good and bad. But even
vancomycin could not avoid resistance forever and as early as 10 years ago S. aureus has begun
to show resistance to vancomycin as well, however these cases still remain rather rare ("NIAID,"
2012).
It is clear that MRSA is a problem that continues to cause numerous problems for the
medical community, insurers, and patients alike. Short term solutions have been found to be
effective and through aggressive hygiene and sanitation campaigns and studies show that the
problem has stabilized and has even began to degrease in frequency. But, the greatest solution to
the problem remains in the ability to educate the community at large to the causes of MRSA and
prevent huge and costly problems like MRSA from occurring in the first place. Providers and
patient need to be made increasingly aware of the harm that antibiotics can cause when they are
abused and misused by doctors and patients. Antibiotics are frequently started and never
finished, used when not need, or even used when expired or prescribed to someone else, these
reoccurring abuses are the root of this problem. Hopefully, as more and more people become
aware of the problem that can potentially be caused by antibiotic misuse everyone will not jump
HOSPITAL AND COMMUNITY AQUIRED MRSA
to using antibiotics or prescribing every time a case of the sniffles begins or because it is what
the patient wants or feels is necessary.
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