Abstract:
The article starts with a brief introduction to MRSA along with description of Staphylococcus aureus. Next the article describes in brief various causes, risks, symptoms and diagnosis for MRSA infection and preventive care.
MRSA Infection
In order to understand Methicillin-Resistant Staphylococcus aureus (MRSA), we need to first understand Staphylococcus aureus. According to Patient UK, Staphylococcus aureus is a bacterium found on the skin and in the nose of healthy people. About 3-10 people are ‘carriers’ of S. aureus being harmless to healthy people, S. aureus infection is caused when a person gets a cut or graze forming boils, pimples, impetigo and skin abscess.
The bacterium S. Aureus affects people with an already poor immune system by getting into the blood. Once the bacterium poisons the blood it can causes conditions such as lung infection (pneumonia), bone infection (ostemyelitis) and heart valve infection (endocaditis). These infections are required to be treated by antibiotics.
There are various strains or subtypes of S. aureus of which some are resistant to the antibiotic “Methicillin” and many other antibiotics. These strains are called Methicillin Resistant Staphylococcus aureus (MRSA). Strains of MRSA are as aggressive and infectious as any other strains of S. aureus, but are difficult to treat since many antibiotics do not act on them. Infections become severe if causes of infection are not diagnosed at the earliest and resistant antibiotics are administered.
Year
Percentage of Infections
1974
2%
1995
22%
2004
63%
It seems more probable that existing transmissible strains were selected by antibiotics, and that spread then occurred mainly in the hospitals, although there are reports of inter-country spread. The reason for a pandemic at this time remains unknown, but possibly the increased use of cephalosporin’s and other newly available antibiotics may have provided the selective influence. It is also possible that there is an as yet unidentified transmissibility factor. A study by Voss and colleagues of 200 isolates from 43 hospitals in ten European countries in 1994 showed that the frequency of MRSA ranged from less than 1% to 30% the incidence was highest in southern Europe. MRSA increase at alarming rate through out the world let us run short of efficient beta-lactam antibiotics of MRSA infection. S. aureus is an aggressive pathogen and is common cause of infections both in hospitals and in communities. The main reason behind the increase of MRSA infection is untreatable multi-resistant S.aureus infections and also influenza outbreak.
MRSA generally affects those who are already ill with wounds or open sores (bed sores) or burns in a hospital environment. Urinary catheters and tubes leading into veins or body (i.e., drips) may sometimes be contaminated by MRSA causing urine or blood infection. MRSA infections are less common outside a hospital environment.
Symptoms of MRSA infections include reddening of skin and inflammation around the affected areas. Other symptoms include fever, lethargy, headache, urinary tract infections, pneumonia, toxic shock syndrome and even death.
Mayo clinic stated that small red bumps are deep, painful abscesses requiring surgical draining.
According to Mayo clinic, the causes for MRSA infection are:
Ø Unnecessary usage of Antibiotic in humans: MRSA is a consequence of “excessive and unnecessary antibiotic use.”
Ø Antibiotics in food and water: Excessive administration of antibiotics to pigs, beef cattle and chickens may finally find their way into municipal water systems, when the runoff from feedlots contaminates streams and groundwater. Antibiotics administered to animals in requisite dosage would avoid the production of resistant bacteria.
Ø Germ Mutation: “Bacteria live on an evolutionary fast track, so germs that survive treatment with one antibiotic soon learn to resist others.” Bacteria mutate much faster than new drugs are produced ending up being highly resistant.
Risk factors for hospital and community strains differ because of the two different settings in which they occur. The risk factors for HA-MRSA are as follows:
Ø A Current or recent hospitalization: MRSA is still a matter of concern in hospitals and health care facilities. Since older patients, people with weakened immune system, burns, surgical wounds or serious underlying health problems.
Ø Residing in a long-term care facility: MRSA is more prevalent in these facilities and carriers of MRSA are active in such areas.
Ø Invasive devices: Patients on dialysis, catherization, feeding tubes or other invasive devices are most vulnerable.
According to Centers for Disease Control and Prevention, there has been a rise in “proportion of infections that are antimicrobial resistant.” The percentage of MRSA infections in different years of the total staph infections are as follows:
Canadian Centre for Occupational Health and Safety (CCOHS) stated that people with long term illness, intensive users of antibiotics, intravenous drug users or immuno-suppressed are at higher risk of being infected by MRSA.
MRSA spreads through physical contact and not through air. Contaminated hands of healthcare workers and medical devices contaminated with body fluids containing MRSA are culprits in spreading germ.
Centers for Disease Control and Prevention stated that MRSA infection can be of two types namely:
Ø Health Care Associated MRSA (HA-MRSA): This type of infection catches up in a health care surrounding such as a hospital, clinic etc.,
Ø Community Associated MRSA (CA-MRSA): Staph or MRSA infections outside health care facilities or hospitals are called CA-MRSA. Skin infections of CA-MRSA are prevalent in athletes, military recruits, children, Pacific Islanders, Alaskan Natives, Native Americans, Homosexuals and prisoners. Various factors are associated with the spread of MRSA skin infections such as close skin-to-skin contact, cuts or abrasions, contaminated items and surfaces, crowded living conditions and poor hygiene.
Main risk factors for CA-MRSA are as follows:
Ø Young Age: Children are most susceptible to CA-MRSA. Once the germ enters through a cut or a scrape, MRSA may cause wide spread infection in children since the immune system of children is not well developed.
Ø Participating in contact sports: CA-MRSA may spread among amateur and professional sports teams through cuts and abrasions and skin-to-skin contact.
Ø Sharing towels or athletic equipments: CA-MRSA spreads among athletes sharing razors, towels, uniforms or equipment.
Ø Weakened immune system: Immunosuppressed people suffer from weakened immune systems and are most likely to have CA-MRSA infections.
Ø Living in crowded or unsanitary conditions: CA-MRSA has occurred in military training camps and in American and European prisons.
Ø Recent hospitalization or antibiotic use: Recent hospital stay or treatment with medications such as fluoroquinolones (ciprofloxacin, ofloxacin or levofloxacin) or cephalosporin increases the risk of CA-MRSA.
Ø Association with health care workers: people in contact with health care workers are at a higher risk of serious staph infections.
MRSA is diagnosed by the doctors by checking a sample tissue or nasal secretions for traces of drug resistant bacteria. The samples are sent to a laboratory for culture and tested.
Dr. Alan Johnson (2007) stated that S. aureus infections are treated with antibiotics such as flucloxacillin (i.e., Floxapen). But this is not effective against MRSA and it is also important to note that MRSA are resistant to antibiotics such as erythromycin and ciprofloxacin. However, MRSA can be treated by administering vancomycin through slow infusion into a vein and teicoplanin can also be injected into a muscle or rapid infusion into a vein. Another drug linezolid can also be administered intravenously in severely ill patients. One more drug “daptomycin (Cubicin) has been licensed for the treatment of skin infections including those caused by MRSA.”
According to Canadian Centre for Occupational Health and Safety (CCOHS) prevention of MRSA infections is based on standard infection control measures:
Ø Hand washing: Hands must be washed immediately after the gloves are removed after examining the patients.
Ø Gloving: Blood, body fluids and contaminated items should not be touched. Gloves should be worn to collect the sample containers.
Ø Masking: Masks and face shields must be worn while performing procedures that generate splashes of blood or body fluids.
Ø Gowning: Gowns should be worn while performing procedures that generate splashes of blood or body fluids.
Ø Patient Care Equipment: Proper cleaning, disinfection and sterilization of all the patient care equipment must be done.
Ø Laundry: Appropriate care must be exercised in handling, transportation and cleaning of used linen. Blood and body fluids should be washed and cleaned to avoid skin exposure and transfer of microbes to other patients.
Ø In case a patient is judged as a case of special significance the patient should be placed in a separate room under complete isolation.
According to Mayo clinic following measures are to be taken to avoid CA-MRSA
Ø Do not share your personal items such as towels, sheets, razors, clothing and athletic equipment with others.
Ø Wounds must be covered with sterile, clean and dry bandages till they heal.
Ø Hands must be washed in or out of hospital.
Question 1. MRSA is a……….
a. Bacterium b. Virus c. Insect d. Chemical
Question 2. The poisoning of blood with Staphylococcus aureus is called………
a. Endocarditis b. Pneumonia c. Septicemia d. Osteomyelitis
Question 3. MRSA spreads through…………….
a. Air b. Physical contact c. Water d. None
Question 4. MRSA infection can be of…………..
a. One type b. Two types d. Three types e. Four types
Question 5. Children are more susceptible to…………
a. Community Associated MRSA (CA-MRSA)
b. Health care Associated MRSA (HA-MRSA)
c. Cuts, burns, electrical shocks etc.,
d. None of the above
Question 6. Strains of MRSA are…………………….aggressive and infectious.
a. Equally. b. unequally c. not harmful d. Varies from strain to strain
Conclusion:
The mechanisms of antibacterial resistance shown by MRSA are diverse and include all known types of resistance such as target alteration, efflux and permeability changes. In addition a number of these mechanisms can be expressed in single isolates often contained within the same transposon or plasmid. This gives MRSA a huge selective advantage in the hospital setting and allows the spread of multi drug resistance clones from ward to ward. Although strict hospital isolation and infection control procedures have helped in the battle to control MRSA, it is quite clear that we still require new antibacterial agents to treat infections caused by this problem bacterium.
References
http://www.link.med.ed.ac.uk/ridu/Mrsa.htm
http://www.cdc.gov/ncidod/dhqp/ar_mrsa.html
http://www.mayoclinic.com/health/mrsa/DS00735
http://www.patient.co.uk/showdoc/27000607/
http://www.netdoctor.co.uk/diseases/facts/mrsa.htm
http://www.nhsdirect.nhs.uk/articles/article.aspx?articleId=252
http://www.ccohs.ca/oshanswers/biol_hazards/methicillin.html
http://www.cdc.gov/ncidod/dhqp/ar_MRSA_spotlight_2006.html
http://www.cdc.gov/ncidod/dhqp/ar_mrsa_ca_public.html
http://www.netdoctor.co.uk/diseases/facts/mrsa.htm
http://www.mayoclinic.com/health/mrsa/DS00735/DSECTION=2
http://www.mayoclinic.com/health/mrsa/DS00735/DSECTION=3
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http://www.mayoclinic.com/health/mrsa/DS00735/DSECTION=8
http://www.patient.co.uk/showdoc/27000607/