MRSA Infection - Research Paper Example

12 September MRSA Infection – Symptoms, Diagnosis, Treatment and Prevention Introduction MRSA (methicillin-resistant Staphylococcus aureus) infection, originally considered a hospital acquired infection, was earlier confined to hospitals but is now emerging in communities as well (Weigelt 5; USAToday.com). The reason for MRSA being a high risk and high alert pathogen is that this strain of S. aureus is resistant to antibiotics, especially beta-lactam antibiotics such as oxacillin, amoxicillin, penicillin and methicillin. MRSA is responsible for causing severe problems such as pneumonia, bloodstream infections and surgical site infections in healthcare settings such as dialysis centers, nursing homes and hospitals (CDC 1). Antibiotics used to treat ordinary S. aureus infections are rendered useless in case of MRSA. Infection occurring in healthcare settings is called health care-associated MRSA (HA-MRSA) while that occurring in the community, among healthy individuals, is called community-associated MRSA (CA-MRSA) (mayoclinic.org 1). HA-MRSA infections are generally acquired through invasive procedures or clinical devices such as artificial joints, surgeries, intravenous tubings and catheters while CA-MRSA generally spreads through skin contact among child care workers, high school wrestlers and people living in crowded areas (mayoclinic.org 1). MRSA infection occurs in various parts of the body and owing to its antibiotic resistance, it is difficult to treat. Mild infections result in boils and sores on the skin. MRSA can also infect lungs, urinary tract and bloodstream (webmd.com 1). There has been an alarming spread in the incidence of tough MRSA strains and because of its antibiotic resistance, MRSA is also called superbug (webmd.com 1). As per CDC, less than 2% of the US population carries MRSA (mayoclinic.org 3). MRSA was discovered in 1961 and research has shown that, like ordinary strains of S. aureus, it is also carried by many healthy people on their bodies, especially their noses (Matheson et al. 299). MRSA infection is common among those with a weaker immune system and while it is commonly a hospital acquired infection, its incidence in people who have not been hospitalized has become recently significant (webmd.com 1). According to reports by the CDC, in the year 2007, 14% of MRSA infections were contracted by people outside a healthcare setting and among children in South Texas, CA-MRSA witnessed a 14-fold increase in a 2 year period (1999-2001) (webmd.com 1). When penicillin resistance staphylococci were first isolated in hospital patients, it was observed that they soon replaced penicillin-susceptible S. aureus in community-associated infections (Weigelt 5). Similar has been the case with MRSA. Although it was earlier mostly isolated in large acute care hospitals, in the past ten years, it is being increasingly isolated in community-associated staphylococcal infections. This movement of the infection into the community cannot simply be termed as “migration” because the community isolates are found to be different from hospital isolates of MRSA (Weigelt 5). Weigelt explains that the reasons for this observation are complex and have not been understood clearly. According to him, perhaps genetic determinants of resistance to methicillin have been grafted into staphyloccus strains that are epidemiologically virulent. MRSA Disease Presentation, Signs and Symptoms Staphylococcal skin infections including those of MRSA initiate as small red bumps that have a close resemblance to spider bites, pimples and boils (mayoclinic.org 2). These may soon turn into painful and deep abscesses requiring surgical draining. While these are mostly confined to the skin, they could also burrow deeper resulting in possibly life-threatening infections of the joints, bones, bloodstream, lungs and heart valves (mayoclinic.org 2). The symptoms of MRSA depend on which body-part is infected. If the skin or soft-tissue is infected, it would result in abscesses, boils or cellulitis (nhs.uk 2). The skin infection would first develop as a painful bump that looks like an insect bite. In addition to this symptom, infected individuals may have other symptoms such as fever and a general feeling of illness. An abscess may also develop as a large pus-filled lump under the skin. CA-MRSA is known to cause more extensive infections such as cellulitis in which the deeper layers of the skin, soft-tissues and fat is infected by the bacteria making the skin appear red, hot, painful and swollen. Invasive MRSA infections are those infections in which the bacteria have penetrated deeper inside the body. Symptoms of invasive infection include a high body temperature (38ºC and above), chills, dizziness, a general sense of feeling ill, muscular aches, confusion, pains, tenderness and swelling. Invasive MRSA infections can cause urinary infections, pneumonia, sepsis, septic bursitis, osteomyelitis, septic arthritis, and endocarditis (nhs.uk 2). Diagnosis Diagnosis of MRSA infections is done through tissue sampling and laboratory investigations of nasal secretions. The isolates are cultured and tested for the presence of antibiotic resistant staphylococci. Recent diagnostic tests detect staphylococcal DNA in just a few hours. Blood cultures are also taken in case of sepsis and invasive infections (mayoclinic.org 7). MRSA Epidemiology MRSA generally spreads through direct contact with contaminated hands or infected wounds (CDC n.p.). Healthy individuals carrying the bacteria without any signs of infection also spread the bacteria to others. According to studies, around 33% of the population carries staphylocci in the nose without showing any illness and two in 100 people are carriers of MRSA (CDC 1). A CDC study has shown that there has been a decline in the number of invasive HA-MRSA infections, with a 54% decline seen between 2005-2011. There have also been fewer MRSA associated deaths among hospital patients in 2011 when compared to 2005 (CDC 1). Staphylococcal infections are highly reported all over the world and an analysis of US inpatients has shown that there are around 400,000 yearly hospital admissions for staphylococcal infections (Boucher and Corey S347). The sophistication of the present medical system has made these medical issues more complex and therefore, their treatment has become more difficult. Annually, around 19,000 hospitalized patients in the US die of MRSA infections annually, which is almost equal to the combined number of deaths due to tuberculosis, AIDS and viral hepatitis (Boucher and Corey S347). Klein et al., using national hospitalizations data reported that in 2009, there were almost 463,017 MRSA-related hospitalizations, with 11.74 hospitalizations per hospital (666). They also reported that differences existed in infections with respect to age, with HA-MRSA–associated hospitalizations being the highest for older individuals. In addition, they also noted that there was a seasonality in the MRSA incidence, especially in children. CA-MRSA was found to peak in the late summer while HA-MRSA peaked in winter. Klein et al. suggest that this seasonality in incidence could be due to seasonal shifts in the pathogen’s antibiotic prescribing patterns (666). Transmissibility MRSA spreads through both indirect and direct contact with patients who are infected or colonized with the pathogen. Poor adherence or lack of adherence to standard infection control precautions leads to transmission of the pathogen (CDC n.p.). MRSA infection especially develops in patients being in hospitals or nursing homes, especially those in surgical wards and intensive care units (nhs.uk 1). The risk factors for HA-MRSA and CA-MRSA differ. Being hospitalized, residing in a long-term care facility and using an invasive medical devices puts patients and healthcare personnel at risk of MRSA infections (mayoclinic.org 4). This is because medical tubing can offer a pathway for MRSA to enter the body. Hospitalized patients also have a weaker immunity and surgical wounds also offer an additional pathway for the pathogen to enter. In case of CA-MRSA, participation in contact sports could pose a risk because the pathogen spreads easily through abrasions, cuts and skin-skin contact. Living in unsanitary or crowded conditions also poses a danger in community settings. Homosexual men are also at a higher risk of acquiring the infection (mayoclinic.org 4). Taking frequent antibiotics, burns, cuts, surgery, skin conditions such as psoriasis or ulcers, use of intravenous drips or catheters, open wounds, longer term conditions such as type 2 diabetes, and weaker immunity are all risk factors that increase the chances of acquiring MRSA infection (webmd.com 1). MRSA Treatment MRSA is difficult to treat because of the antibiotic resistance of the pathogen. However, both CA-MRSA and HA-MRSA strains do respond to specific antibiotics, while in some cases, the use of antibiotics may not be necessary (mayoclinic.org 8). For instance, a superficial abscess could be drained rather than being treated with drugs. Minor skin infections do not generally require treatment apart from draining away pus from the infection site (nhs.uk 4). Alternately, the infections could be treated with antibiotics that the pathogen has not yet developed resistance to. However, the exact antibiotic used for a patient depends on the susceptibility of the individual strain affecting the patient. Based on the severity of symptoms, injections or antibiotics may be prescribed and the course of treatment for MRSA is generally much longer than that for ordinary staphylococcal infections (nhs.uk 4). Antibiotic susceptibility and resistance of the specific MRSA strain of the patient is required for establishing the right antibiotic treatment. The therapy is based on results of laboratory microbiological tests for antibiotic susceptibility, such as the Kirby-Bauer antibiotic disc test (emedicinehealth.com n.p.). These tests are time consuming. For patients with MRSA, taking antibiotics at the right time as directed is essential and patients should not stop using the prescribed antibiotic even if the symptoms resolve before the culmination of the prescribed dose (emedicinehealth.com n.p.). Stopping the antibiotics early would allow the bacteria to survive and to further develop antibiotic resistance. Severe MRSA infections require treatment with two or more antibiotics administered intravenously in combination. For instance, some combinations commonly given to MRSA patients are vancomycin, linezolid [Zyvox], rifampin [Rifadin], sulfamethoxazole-trimethoprim. Mupirocin (Bactroban) works well for minor skin infections (emedicinehealth.com n.p.). Some patients could still die despite antibiotic therapy if the patient’s defence mechanism is overwhelmed by the infection (emedicinehealth.com n.p.). MRSA Prognosis Studies have shown that MRSA infections can be prevented to some extent if healthcare personnel follow CDC guidelines (CDC 1). The prognosis of MRSA infection, according to the National Institutes of Health, US, varies depending upon the severity of the infection itself and the general condition of the infected person (emedicinehealth.com n.p.). Those with good health in general but with mild CA-MRSA would recover easily in most cases. Those with mild to moderate skin infections such as boils and small abscesses also have excellent prognosis with proper and early treatment. The outcomes of severe and extensive MRSA infections vary from good to poor. MRSA sepsis and pneumonia have high mortality rates with the calculated death rate of invasive MRSA being 20% (emedicinehealth.com n.p.). As for the recurrence of MRSA infections, there is sparse data. Recurrence for mild MRSA infections is rare although patients could be carriers for up to about 30 months. The patient could also be contagious in this period. In HIV patients, there could be a recurrence rate of 21% after the initial MRSA diagnosis (emedicinehealth.com n.p.). Complications of the disease include scarring, organ damage, pneumonia, tissue loss and sepsis. Intestinal infection by Clostridium difficile is also a possibility due to antibiotic therapy (emedicinehealth.com n.p.). Prevention Prevention of HA-MRSA could be done by following strict hygiene procedures and sterilizing contaminated laundry and surfaces. For the prevention of CA-MRSA, people should ensure they wash their hands carefully and thoroughly. The hands should be scrubbed for at least 15 seconds and dried using a clean disposable towel (mayoclinic.org 7). People should also carry hand sanitizers with them containing at least 67% alcohol. Cuts and abrasions should be kept covered with sterile bandages until they heal. Personal items like towels, razors, clothes, etc. could be contaminated and therefore, should not be shared. People should also make sure they shower immediately after every athletic game or practice using soap and water. Bed linens and wash towels should always be sanitized using hot water with bleach. The rates of MRSA infections have fallen in the recent years due to increased awareness in people and the medical staff (nhs.uk 4). Conclusion According to reports by USA Today, MRSA infections, especially those outside healthcare settings are more common than what is suggested by government statistics (1). Because of the inability to detect MRSA cases and track them, efforts by public health officials for developing prevention strategies are facing great challenges (USAToday 1). MRSA infection caused by methicillin staphylococci are extremely challenging to treat but much less challenging to prevent. Despite the presence of antibiotic resistance, MRSA infections are not completely untreatable, although certainly difficult. Awareness of MRSA prevention guidelines is necessary, especially for those working in healthcare settings. Works Cited Boucher, Helen, and Ralph Corey. “Epidemiology of Methicillin-Resistant Staphylococcus aureus.” Clinical Infectious Diseases, 46: 2008, S344-S349. CDC. “Methicillin-resistant Staphylococcus aureus (MRSA) Infections.” CDC.gov (2014). Web. . Klein, Eili, Lova Sun, David Smith, and Ramanan Laxminarayan. “The Changing Epidemiology of Methicillin-Resistant Staphylococcus aureus in the United States: A National Observational Study.” American Journal of Epidemiology, 17(7): 2013, 666-674. Matheson, Eric, Arch Mainous, Charles Everett, and Dana King. “Tea and Coffee Consumption and MRSA Nasal Carriage.” Annals of Family Medicine, 9(4): 2004, 299-304. Mayoclinic.org. “MRSA infection.” Mayo Clinic (2012). Web. . Nhs.uk. “MRSA infection.” NHS Choices (2013). Web. . USA Today. “Dangerous MRSA bacteria expand into communities.” Usatoday.com (2013). Web. . Webmd.com. “Understanding MRSA Infection -- the Basics.” WebMD (2014). Web. . Weigelt, John. MRSA. New York: CRC Press, 2007. Read More