Methicillin Resistant Staphylococcus

Aureus and Public HealthREBECCA ROYTEN

CONCORDIA UNIVERSITY

What is Methicillin Resistant Staphylococcus Aureus (MRSA)?

MRSA infection is caused by a strain of staphylococcus

that is resistant to antibiotics. There are two

categories of MRSA, there is HA-MRSA that is found in the hospital setting and is the cause of all hospital induced infections and

there is CA-MRSA strain that is found outside the hospital

setting in the community (Otto, 2012).

MRSA and EpidemiologyRisk Factors

HA-MRSA The main risk factor for HA-MRSA is

the hospital setting. Hospitals contain the more vulnerable population, those with weakened immune systems (Mayo Clinic, 2014)

Those who have had invasive procedures like surgeries and joint replacement (Mayo Clinic, 2014)

Those with medical tubing (CDC, 2014b)

HA-MRSA can occur anywhere healthcare is delivered (CDC, 2014b)

CA-MRSA The main risk factor for CA-MRSA

is direct contact with an infected wound

Sharing personal items that have touched infected skin (Mayo Clinic, 2014)

Mostly found in crowded or unsanitary conditions like military barracks, child care centers, school settings, contact sports and jails (CDC, 2014b)

MRSA and EpidemiologyDistribution of Disease

HA-MRSA It wasn’t until the 1960’s that the first strains of antibiotic resistant bacteria were

identified (David, 2010)

HA-MRSA infections distribution is limited to a hospital associated pathogen (Otto, 2012)

30 years ago MRSA accounted for 2% of total staphylococcus infections, by 2003 they were 64% of staphylococcus infections (CDC, 2014b)

HA-MRSA is confined largely to hospitals, other health care environments, and patients who frequent those facilities (David, 2010).

MRSA and EpidemiologyDistribution of Disease

CA-MRSA

In 1999 the first documented cases of severe infections of soft tissue occurred outside the hospital setting and the strain CA-MRSA was identified (Otto, 2012)

This shows that MRSA is accumulating further resistance to antibiotics creating a highly virulent, hard to treat superbug (Otto, 2012)

CA-MRSA strains infect a different group of patients and they have a different susceptibility pattern than HA-MRSA

HA-MRSA susceptibility pattern is in those with weakened immune systems while CA-MRSA spreads rapidly among healthy people (David, 2010)

There is no data currently on the total number of CA-MRSA infections in the U.S. as of now

MRSA and Biostatistics

National Institute of Health In 2005 the NIH did a study that

determined that 1% of all hospital stays were associated with MRSA infections (NIH, 2014).

This accounts for 292,045 infections, which identifies MRSA infections as a public health threat (NIH, 2014)

They also found that those with MRSA infections were at a higher risk of mortality than other hospital born illness (NIH, 2014)

Centers for Disease Control The CDC looked back on all episodes of

MRSA at a specific hospital from 2002-2007 (Pastagia, 2012)

Determined that those with MRSA infections had an increased stay, with the average patient staying 32.9 days (Pastagia, 2012).

Determined that more than 40% of infections had recent surgeries and more than 40% had catheters (Pastagia, 2012)

Noticed that the elderly, those with cirrhosis, those with renal insufficiency, those living in a nursing home before entering the hospital had an increased mortality rate of 7-15% (Pastagia, 2012)

In order to understand the risk factors and the level of threat MRSA infections impose on public health initial research had to be done. Several retrospective

cohort studies were done by several agencies.

MRSA and Biostatistics

By using the information studies like those two retrospective cohort studies gathered clinicians were able to collaborate on research and target their approach to treating MRSA infections and preventing MRSA infections.

These studies helped to identify those who were most susceptible and where the chains of contact may be most prevalent. This information is vital to create successful programs to decrease MRSA infections.

The CDC used this info to establish that MRSA was indeed a threat to public health and there was a need for preventive measures to decrease the amount of serious MRSA infections.

MRSA and Biostatistics

2010 20110

5

10

15

20

25

30

Incidence rateIncidence rate of mortality The CDC started an Active Bacterial

Core Surveillance Report (ABC) to be done every year starting in 2004, in order to track prevalence of MRSA infections and to determine if preventive measures were successful (CDC, 2012).

The CDC tracks incidence rates every year from 9 states which totals 19,635,461 people (CDC, 2012)

When reports are compared from year to year there is a decrease in the incidence rates of infection and mortality (CDC, 2010)

This shows that the efforts of the CDC have been successful and hospital onset infections have fallenThe Incidence rate for the ABC report

were 1 to 100,000 (CDC, 2012)

MRSA and Biological and Molecular Characteristics

Staphylococcus aureus is colonized naturally in one third of the population on the nose, throat and skin and can be spread by direct or indirect contact (Todar, 2012)

MRSA strains are staphylococcus aureus strains that have become resistant to methicillin, amoxicillin, penicillin and all beta-lactam antibiotics (Olughenga, 2013)

Antibiotic resistance is the ability of bacteria to resist the effects of an antibiotic and occurs when a bacteria changes or mutates in some way that reduces or eliminates the effectiveness of the antibiotic (CDC, 2014a)

MRSA and Biological and Molecular Characteristics

Burst the Cell Wall

Bacteria produce a cell wall that is partly made up of a macromolecule called peptidoglycan

which human cells do not make or need. Antibiotics

prevent the final cross linking step in the

assembly of peptidoglycan which

creates a fragile cell wall. This cell wall will burst

and kill the bacteria (Mobley, 2006)

Target Pathways

Antibiotics can also target bacteria’s

metabolic pathways. They can block the bacteria’s growth or

reproduction by preventing nutrients

from reaching the bacteria which prevents them from dividing or

multiplying (AAP, 2014)

Block RNA

Antibiotics can target protein synthesis. If protein synthesis is

stopped the bacteria dies. If protein

synthesis is blocked than the RNA

interaction is blocked and the proteins can no

longer change (Mobley, 2006)

Antibiotics attack the disease process by destroying the structure of bacteria or their ability to divide or reproduce.

They can do this in different ways (AAP, 2014)

MRSA and Biological and Molecular Characteristics

One way for bacteria to develop a resistance to antibiotics is epigenetic adaption which involves no genetic mutation (CDC, 2014a)

They do this by mobilizing defenses such as pumps to expel the antibiotic or they develop enzymes to break the antibiotic down (The Science of Acne, 2014)

This does not include nor require a genetic change that is inherited by the next generation (The Science of Acne, 2014)

Another way bacteria develop resistance is through genetic adaption. (CDC, 2014a)

Genetic adaption is when a bacteria is exposed to a small non lethal dose of antibiotic and they develop small changes in genetic code (CDC, 2014a)

If one bacteria escapes the effect of the antibiotic it can multiply and replace the killed bacteria (CDC, 2014a)

MRSA and Social and Behavioral Factors

The main social and behavioral factors in regards to HA-MRSA are inappropriate use of antibiotics (CDC, 2013a)

The social and behavioral factors in regards to CA-MRSA are personal hygiene issues (CDC, 2014b)

Both the HA-MRSA and CA-MRSA behavioral factors can be influenced when you take into consideration the five levels in the ecological model of health behavior

These levels are interpersonal factors, interpersonal relations, institutional setting, community and public policy (Schneider, 2014)

MRSA and Social and Behavioral Factors

HA-MRSA Education on appropriate use of

antibiotics can change the attitudes and ideas of an individual ad their social network

People should know to take antibiotics only when prescribed by a physician, follow all directions, take entire regime, throw away unused antibiotics, do not share antibiotics and not take for viral infections (CDC, 2013a)

CA-MRSA Knowledge and education are the

best way to influence behavior

Since CA-MRSA is found most commonly in unsanitary or crowded conditions education on good hygiene and proper sanitary conditions would decrease the spread of CA-MRSA (CDC, 2014B)

Coaches and parents should encourage good player hygiene and teach avoidance of sharing personal items (CDC, 2014b)

Interpersonal factors and interpersonal relations of HA-MRSA and CA-MRSA are both

affected by education and knowledge

MRSA and Social and Behavioral Factors

HA-MRSACommunity and Institutional

The education on antibiotic usage comes from healthcare workers. The CDC has developed the Antibiotic Stewardship where doctors and health care workers adopt a principle of responsible antibiotic use (CDC,

2013b)

Public Policy

Behavioral factors can be affected by strengthening infection control and prevention, regulate and promote appropriate use of medicines and fostering research of new treatment options (WHO, 2014)

CA-MRSAInstitutions and Community

Behavioral factors can be influenced through schools and sports team administrators. Sport administrators should be encouraged to provide facilities and equipment necessary to promote good hygiene, clean facilities and adequate supplies of soap and towels (CDC, 2014a)

Behavioral factors can be influenced in prisons through hygiene education for inmates, antibacterial soap and improved laundering methods (Eisler, 2013)

The three other levels of behavioral change in the ecological model are institutional setting, community and

public policy (Schneider, 2014)

MRSA and Social and Behavioral Factors

The health belief model is the most effective psychological model in regards to HA-MRSA

There are several factors in the health belief model that determine whether a person is likely to change behaviors when faced with a public health threat like MRSA (Schneider, 2014)

These factors are the extent to which a person feels vulnerable to the threat, the perceived severity of threat and the perceived barriers to taking action to decrease risk and the perceived effectiveness of taking action to prevent or minimize the problem (Schneider, 2014)

MRSA and Social and Behavioral Factors

Extent to which a person feels vulnerable

- Almost all Americans will receive medical care at some point in their lives (CDC, 2013)

- MRSA infections are highly transmissible and can be spread to family members, coworkers and friends which threatens the community (Hildreth, 2009)

- Antibiotics are a limited resource and the more that are used today the less effective they will be in the future making people vulnerable to infections with no treatment (CDC, 2013b)

Perceived severity of threat

- Common infections become harder to treat and can become life threatening when they are resistant to antibiotics (Hildreth, 2009)

- They require longer, more expensive, and more toxic treatment. This increases the risk of transmission and increases the cost of health care (Hildreth, 2009)

- MRSA infections have a 64% more chance of death than non-resistant infections (WHO, 2014)

Barriers to taking action

-The only barrier is a lack of understanding of inappropriate use of antibiotics

-People who are unaware that antibiotics are ineffective against viruses may demand them from their physicians (CDC, 2013a)

-Those who do not understand the importance of finishing an entire regime; by not finishing a prescription the bacteria left behind can develop antibiotic resistance (CDC, 2013a)

Perceived Effectiveness

- Easily influenced by statistical data

- There has been a steady decline of incidence rates in regards to HA-MRSA since the CDC implemented recommendations and the Antibiotic Stewardship (CDC,

2012)

MRSA and Social and Behavioral Factors

CA-MRSA behavioral change is most effective via the transtheoretical model in regards to psychological methods

The transtheoretical model envisions change through five stages, precontemplation, contemplation, preparation, action and maintenance (Schneider, 2014)

In order to increase hygiene a person has to first precontemplate or think about the positive effect of increasing hygiene and then they need to contemplate the benefits of this changed behavior

Next a person has to begin the preparation stage and develop a course of action

This leads to action where a patient will modify their behavior and finally maintenance (Schneider, 2014)

MRSA and Public Health

It is important to understand MRSA and how to decrease MRSA infections in order to protect one of our greatest tools in the battle of infectious diseases

Antibiotics have saved millions of lives (CDC, 2014a)

With the emergence of antibiotic resistant bacteria like MRSA we find ourselves facing highly virulent and hard to treat superbugs (Otto, 2012).

ReferencesAmerican Academy of Pediatrics. (2014). How do antibitoics work. Retrieved from www.healthyChildren.org/English/health-issues/comditions/treatments/pages/How-do-antibiotics-work.aspx

Centers for Disease Control and Prevention. (2010). Active bacterial core surveillance report, emerging infections program network,

methicillin- resistant staphylococcus aureus, 2010.

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use/antibiotic-resistance-faqs.html

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Eisler, P., Fecto, M. (2013, Dec 18). MRSA bacterium target crowded places with poor hygiene. USA Today. Retrievedwww.usatoday.com/story/news/nutrition/2013/12/16/mrsa-emerging-in- schools-prisons-athletic-facilities/4013153/

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National Institute of Health. (2014). Methicillin-resistant staphylococcus aureus (MRSA). www.niaid.nih.gov/topics/antimicrobialResistance/Examples/mrsa/Pages/overview/aspx

Olughenga A., Olayinka O., Samuel T., Olusola O., Oluyinka O., Oloyede S., Abiodun A., Olufunmilola B., David O., Oyebode T. (2013). Phenotypic and molecular

characteristics of methicillin- resistant staphylococcus aureus isolates. Infections and Drug Resistance, 6:87-92 doi.10.2147/IDR.S48809

ReferencesOtto, Michael (2012). MRSA virulence and spread. Cellular Microbiology,

14(10), 1513-1521. doi:10.1111/j.1462-5822.2012.01832.x

Pastagia M., Kleinman LC, Lacerda de la Cruz EG, Jenkins SG. Predicting risk for death from MRSA Bacteremia. 2012 July.

http://dx.doi.org/10.3201.eid1807.101371

Schneider, M. (2014). How psychosocial factors affect health behavior. In Introduction to Public Health. Jones and Bartlett Learning, LLC and Ascend Learning Company (pp. 221-236).

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