MRSA is a strain of staphylococcal bacteria which is multidrug resistant and the infections caused by MRSA are difficult to treat. MRSA is an important entity in both community and hospital acquired infections. Over time, the rate of MRSA infections has increased and therefore there is a general concern amongst healthcare professionals to control the spread of this infection.
Initially, in the early 1960’s MRSA infections were only limited to Europe and Asia but in the past two decades newer strains of MRSA have emerged which are resistant to multiple antibiotics and the infection has now become widespread in many different parts of the world (Casewell, 1986). MRSA was well-known to cause hospital acquired or nosocomial infections but in the past few years community acquired MRSA infections have also become very common (Cookson, 2000).
It has been reported that 32% of U.S. population is colonized with Staph. Aureus and 0.8% by MRSA (Kuehnert, 2006). The proportion of nosocomial MRSA infections has also increased drastically from 2% in 1974 to 64% in 2004 in U.S. (Klevens, 2006). Similarly, 6.9% of MRSA prevalence was seen in New Zealand in 2001 (ESR. Antibiotic resistance, 2001). Now the proportion of multiresistant MRSA has also increased in New Zealand from less than 20% in 1990s to more than 40% in 2000-01 (ESR. Antibiotic resistance, 2001).
MRSA was first discovered in 1961. It belongs to the large group of bacteria known as staphylococci. MRSA is defined as the bacterium which is resistant to penicillin and standard penicillin-related antibiotics. The resistance of MRSA to methicillin is due to a penicillin-binding protein known as methicillin resistant gene (mecA).
MRSA usually causes the same spectrum of diseases as Staphylococcus Aureus but the only difference is their resistance to treatment. The most common infections seen are skin infections. The common symptoms are erythema, warmth, pain, swollen and tender skin lesions, etc. the skin infections commonly seen are cellulitis, carbuncles, furuncles, folliculitis, sty, abscesses and impetigo. MRSA infections can spread throughout the body and affect internal organs. This can result in more serious symptoms like low BP, fever, headache, joint pain and shortness of breath (Understanding MRSA (Methicillin resistant Staphylococcus aureus)).
The main mode of transmission of MRSA is physical contact. This means that MRSA can be transmitted from person to person contact, i.e. from people who are infected or colonized by MRSA. It can also be transmitted from objects with MRSA like tables, door handles, towels, floor and instruments or apparatus which has been used by the person with MRSA infection or colonization.
Since MRSA is transmitted by close contact, outbreaks are usually seen in schools, army, dormitories, prisoners, team players, etc. There are certain risk factors which have been identified for acquiring MRSA infections. These include immunocompromised patients (HIV, infants), diabetics, hospitalized patients, surgical patients, health care workers, etc.
There are number of ways to prevent the spread of MRSA infections. The first important step of prevention is effective screening. Patients should be screened for MRSA upon hospital admission by taking nasal swab, perineal swab, swab from the site of infection, tracheostomy, cannula and catheter and urine sample (if catheter is in place). Three sets of screening swab should be taken for patients who have been infected by MRSA previously and they should also be kept in contact isolation. Patients who are found to be MRSA- positive on screening test should be isolated and decolonized. The rooms and accessories of all these patients should be cleaned and sanitized properly and all the equipment and surgical instruments used on these patients should be strictly handled with care and decontaminated before using on other patients. Whenever examining these patients, gloves, gown and masks should be worn. All MRSA positive patients should be properly labeled so that all the health care professionals, working staff and visitors are aware of the risk and take all precautionary measures.
Proper hand washing and hygiene is the basic and most important step in prevention of MRSA infection. Hands should be washed and disinfected (using alcohol gel, etc) after encounter and examination of every patient. This is for the safety and protection of one’s own health as well as of other patients.
Specific programs should be introduced to control and reduce the burden of MRSA infections and proper guidelines should be formulated for detection, prevention and treatment of MRSA.
It is important to realize that although MRSA is resistant to a lot of antibiotics, it can still be treated with many other antibiotics available if the medications are taken in proper dosage for adequate duration of time. It is rare for MRSA infections to become life threatening if they are properly treated on time. Both nosocomial and community acquired MRSA is resistant to standard penicillin and penicillin-related antibiotics. Therefore MRSA susceptibility is first checked against different antibiotics including co-trimoxazole, erythromycin, fusidic acid, mupirocin, tetracycline, ciprofloxacin, clindamycin, gentamicin, rifampicin and vancomycin vancomycin. Community acquired MRSA is susceptible to antibiotics like trimethoprim-sulphamethoxazole, tetracyclines and clindamycin. But nosocomial MRSA is resistant even to these antibiotics. So in treatment of such cases, antibiotic like vancomycin, teicoplanin, dalfopristin and linezolid are used. Mupirocin is a topical antibiotic which is commonly used to clear MRSA from carriers (Understanding MRSA (Methicillin resistant Staphylococcus aureus)).
In a nutshell, MRSA infections are widespread and continue to increase till date. Therefore, appropriate measures should be taken to control the spread and prevent further infections. This requires early detection and screening for MRSA, efficient prevention-control programs and adequate treatment with antibiotics before the disease becomes life threatening.
References
Casewell. (1986). Epidemiology and control of the modern methicillin-resistant Staphylococcus aureus. J Hosp Infect , S1-11.
Cookson. (2000). Methicillin-resistant Staphylococcus aureus in the community: new battlefronts, or are the battles lost? Infect Control Hosp Epidemiol , 21, 398-403.
ESR. Antibiotic resistance. (2001). LabLink , 8, 21-2.
Klevens. (2006). Clinical Infectious Diseases. Clinical Infectious Diseases , 42, 389-91.
Kuehnert. (2006). Staphylococcal Disease Burden. Journal of Infectious Diseases. , 172-9.
Understanding MRSA (Methicillin resistant Staphylococcus aureus). (n.d.).