Download Methicillin-Resistant Staphylococcus aures (MRSA)

Methicillin-Resistant Staphylococcus aures (MRSA)
MPH 510 Applied Epidemiology
Concordia University
January 28, 2015
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Hospital-acquired infections with Staphylococcus aureus are a major cause of
illness and death (Klein, Smith, and Laxminarayan, 2007). It caused things like lower
respiratory tract infections and surgical site infections. During the period of 1995-2005
hospitalized related MRSA doubled, indicating that this should be a national priority for
disease control. Once the use of penicillin grew in the 1940s-1960s, an antibiotic, the
resistance began. It was contained to a insignificant group, but then later grew into large
numbers. (Klein, Smith, and Laxminarayan, 2007).
The problem behind this infection, is it is commonly found in multiple places.
People can acquire this in settings like health care-associated MRSA (HA-MRSA) like in
nursing homes, or community-associated MRSA (CA-MRSA) that spreads by skin-toskin contact (May Clinic, 2012). Since this is very easy to spread, people that are at risk
are child care workers, and people who live in crowded conditions. When the infection is
contracted in HA-MRSA, it can cause life-threatening bloodstream infections,
pneumonia, and surgical site infections (CDC, 2013).
The significance of this problem is the bacterium becomes resistant to the
antibiotics making it difficult to rid it of the body. The Mayo Clinic states, the reason for
the antibiotic resistance is the end result of long term use of unnecessary antibiotic use.
Some individuals, about two in every 100, carry MRSA on their skin or in their nose,
without showing any signs or symptoms and can spread it to others by skin-to-skin
contact. This can also be spread from infected hands from health care workers called
cross contamination. Without doing cultures on the infected area, the individual will not
know they have an infection being caused by MRSA. (CDC, 2013).
The extent of this problem is beyond containment. This bacteria can change itself
to be resistant from antibiotics, with every mutation it has it makes it harder to treat. Thus
leading to harmful effects on the body. (CDC, 2011).
Reports have shown that people who are on dialysis have a higher risk of this
infection. Below is a table taken from the Center for Disease Control. The information
was gathered from a study conducted to track MRSA infection rates.
National Estimates and Adjusted Incidence Rates of Invasive MRSA Infections
Epidemiologic
Category
CA
Non-Dialysis Patients
Incidence
Estimated
Rate
No.
(Confidence
Interval)a
4.82 (3.6915,138
6.42)
Estimated Cases of Infection
Dialysis Patients
Incidence
Estimated
Rate
No.
(Confidence
Interval)b
NA
NA
Total
Incidence
Estima
Rate
ted No. (Confidenc
e Interval)
4.82 (3.6915,138
6.42)
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HCA
44,771
14.29 (12.4016.62)
HCA-HO
11,493
3.67 (2.735.02)
1,408
HCA-HACO
61,268
10.62 (9.0612.55)
12,633
Overallc
65,296
19.54 (17.2422.31)
14,041
14,041
3262.39
(2496.824247.12)
327.24
(131.31739.07)
2936.08
(2216.063876.65)
3263.31
(2496.124248.98)
58,812
18.74
(15.8122.42)
12,901
4.11 (2.906.02)
45,911
75,309
14.63
(12.0917.85)
23.99
(20.6428.10)
aNational Estimates and Incidence (no. per 100,000 population per year) are adjusted
for age, race, gender and receipt of chronic dialysis using 2012 US Census Data. bNational Estimates and Incidence (no. per 100,000 dialysis patients per year) for
dialysis patients are adjusted for age, race and gender using 2011 USRDS point
prevalence data. c80 cases could not be classified into an epidemiological category or category is
unknown and therefore are counted in the overall estimate only.
dStarting in 2011, confidence intervals on national estimates were determined for
each of the 72 age/race/gender/dialysis specific strata and summarized for an overall
national estimate, accounting for variance across all strata producing a more
conservative estimate (with wider confidence intervals) compared to estimates prior
to 2011.
(http://www.cdc.gov/mrsa/tracking/index.html)
The agents that is responsible for this problem is Methicillin-resistant
Staphylococcus aureus (MRSA). This is ‘an infection caused by a strain of staph bacteria
that’s become resistant to antibiotics that are commonly used to treat ordinary staph
infections’ (Mayo Clinic, 2012).
Once the MRSA is contracted into the body, it ‘generally starts as small red
bumps that resemble pimples, boils or spider bites… quickly [these can] turn into deep,
painful abscesses that require surgical draining’ (Mayo Clinic, 2012). While some of the
bacteria can stay localized at the site of infection, others can penetrate into the body
causing threatening infections in heart valves, lungs, and bones (Mayo Clinic, 2012).
Based off a study that was conducted from 1999-2005 tracking the
hospitalizations and deaths caused by MRSA in the USA, there is a significant increase in
events of this illness. (Klein, Smith, and Laxminarayan, 2007).
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Estimated methicillin-resistant Staphylococcus aureus (MRSA)–related hospitalization
rates, United States, 1999–2005. Rates are no. MRSA-related discharges/1,000
hospitalizations. Error bars represent 95% confidence intervals.
(http://wwwnc.cdc.gov/eid/article/13/12/07-0629-f1)
Within this same study, results had shown estimated death rates from MRSA and
S.aureus. This information is presented in a table shown below. “In 2005 there were
~11,406 S.aureus related deaths (95% CI 7,609-15,203, of which 6,639 were MRSArelated (95% CI 4,429-8,850)” (Klein, Smith, and Laxminarayan, 2007).
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Figure 3. Estimated hospital deaths associated with Staphylococcus aureus and
methicillin-resistant S. aureus (MRSA), United States, 1999–2005. Error bars
represent 95% confidence intervals.
Another study reported by the CDC that was tracking the MRSA incidents shows the age
groups that were affected.
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HO- Hospital Onset. HACO- healthcare-associated community onset. CA- communityassociated.
As you can see from this table, it shows that the age group that is more at risk is
very young and the elderly. Also as the age group increases the HACO have the highest
incident rates of MRSA.
The poor and obese are more likely to contract a community associated infection.
Some may argue that this is an endemic and an epidemic within the US. It has
spread in the communities, becoming the dominant cause of CA skin and soft tissue
infections (Klein, Smith, and Laxminarayan, 2007).
Certain occupations are at high risk of contracting this illness. The Occupational
Safety & Health Administration (OSHA) states that health care workers (HCWs) are in
that high risk category. (OSHA, 2014). They are at high risk because they aid in the
recovery of the ill, who sometimes are not diagnosed with the infectious disease and
should continue to use safety measures to protect themselves from MRSA. Since this is a
contact transmissible infectious agent, with direct and indirect transmission, HCWs are
always at risk (OSHA, 2014).
A Johns Hopkins researcher found that MRSA has a seasonal infection trend on
age groups. Children are at greater risk during the summer time and seniors are at greater
risk in the winter. It isn’t stated the actual reason for this trend. (Johns Hopkins
Medicine, 2013).
The current hypotheses that have been reported to be a cause of the distribution is
the over use of or unnecessary use of antibiotics.
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The lack in knowledge or the need for more research would be more updated
information and updated research. While there is information, there updated research on
the statistics of infection rates would signify if this issue is continuing to be an epidemic.
References
Center for Disease Control and Prevention. (202, June 6). ABCs | Bacterial Surveillance |
2011 MRSA Report | CDC. Retrieved from http://www.cdc.gov/abcs/reportsfindings/survreports/mrsa11.html
Center for Disease Control and Prevention. (2013, September 16). General Information |
Healthcare Settings | MRSA | CDC. Retrieved from
http://www.cdc.gov/mrsa/healthcare/
Center for Disease Control and Prevention. (2007, November 12). Hospitalizations and
Deaths Caused by Methicillin-Resistant Staphylococcus aureus, United States,
1999–2005 - Volume 13, Number 12—December 2007 - Emerging Infectious
Disease journal - CDC. Retrieved from
http://wwwnc.cdc.gov/eid/article/13/12/07-0629_article
Center for Disease Control and Prevention. (2013, September 13). Methicillin-resistant
Staphylococcus Aureus (MRSA) Infections | CDC. Retrieved from
http://www.cdc.gov/mrsa/
Center for Disease Control and Prevention. (2013, September 16). MRSA Tracking |
MRSA | CDC. Retrieved from http://www.cdc.gov/mrsa/tracking/index.html
Fact Sheet. (n.d.). Retrieved from http://www.nfid.org/publications/factsheets/mrsa.pdf
Johns Hopkins Medicine. (2013, February 28). Strains of Antibiotic-Resistant 'Staph'
Bacteria Show Seasonal Preference; Children at Higher Risk in Summer.
Retrieved from
www.hopkinsmedicine.org/news/media/releases/strains_of_antibiotic_resistant_st
aph_bacteria_show_seasonal_preference_children_at_higher_risk_in_summer
MRSA infection Definition - Diseases and Conditions - Mayo Clinic. (2012, November
12). Retrieved from http://www.mayoclinic.org/diseasesconditions/mrsa/basics/definition/con-20024479
Occupational Safety & Health Administration. (n.d.). Safety and Health Topics |
Healthcare - Infectious Diseases. Retrieved from
https://www.osha.gov/SLTC/healthcarefacilities/infectious_diseases.html