Methicillin-resistant Staphylococcus aureus is a strain of the bacterium that is commonly shortened as 'staph.' Unlike garden variety staph infection, MRSA is resistant to many antibiotics. Depending on the source and site of the infection, boils and sores are possible. Other serious skin infections can occur while the bacteria may infect other organs in the body, enter the bloodstream or infect wounds. Staph is commonly present in the nose and on the skin; it is only is of any concern if and when it enters the body elsewhere through a cut or abrasion, for example. If treatment is delayed, it may worsen or become more difficult to treat in general. It's resistant properties have led the US Centers for Disease Control to characterize the sometimes life threatening strain as a "superbug." While one in three people carry the generic staph bacterium, approximately two in every hundred carry MRSA. Infection from staph is fairly common and does not require special care, beyond the usual line of antibiotics.
Certain bacteria will develop antibiotic resistance as the result of a sort of microcosmic natural selection. Genetic mutations in a portion of the bacterial population become favorable if they help the bacteria resist a given antibiotic. The mutated segment of the population will survive the course of antibiotics and reproduce. Whereas the resistant bacteria was once a mere portion of the population, it now constitutes the entire infection. MRSA was discovered by doctors in 1961, and over the years has become resistant to a slew of other antibiotics including amoxicillin, penicillin, oxacillin, and others. The administration of antibiotics, though critical to the maintenance of public health, can create a natural selection battleground wherein "susceptible" bacteria are eradicated and only the "strong" and resistant strains are left to reproduce more bacteria with their "favorable" genetic mutations. While certain antibiotics remain powerful enough to knock out a case of a MRSA, the strain is ever-evolving. As researchers develop new and more powerful antibiotics, bacteria and science effectively try to outpace one another.
Antibiotic resistance, once developed, can be spread and transferred through bacterial strains at an alarming pace. For example, just 2% of staph strains in England were methicillin resistant in 1990. By 2002, 46% of staph strains were methicillin resistant.
Healthcare facilities and nursing homes facilitate the spread of MRSA. Infections are common in those with weak immune systems or who frequent the aforementioned areas. Post surgery wound infections with MRSA have been known to occur, as well as infections resulting from vein catheters. The bacteria can infect soft tissue, bone, heart valves. organ abscesses, joints or the bloodstream.
MRSA is most-commonly spread by hand to hand contact, or contact with an existing infection, wound secretion or mucous. This may occur with the sharing of personal items such as razors and towels, or by direct contact with skin on which MRSA is already present. This type of transmission is referred to as community MRSA. Community MRSA (CA MRSA) is distinct from healthcare associated MRSA (HA MRSA). Close quarters encourage the spread of CA MRSA, which tends to afflict younger people. HA MRSA more commonly afflicts the elderly, in their late sixties on average. Anyone is at risk, especially those who frequently find themselves in crowded areas, making an excess of skin to skin contact. Although people in hospitals have been at an increased risk of contracting the infection, incidence has dropped nearly 50% between 1997 and 2007.
A person may be infected with MRSA if they experience an irritated bump on the skin which they may presume to be an insect bite of some sort. It may also manifest as a boil or pus filled pimple. It may progress into a swollen tender abscess, which when cut or bursts open, an excess of pus or fluid may drain from the area. Depending on the severity of infection, this may be accompanied by shaking chills and fever.
It is not immediately possible for someone to tell if they are infected with staph or MRSA. If they are concerned, they are advised to wash their hands, avoid skin to skin contact with others and contact their doctor immediately.
Once a boil or abscess has been drained, it may not require further treatment. A doctor will make a determination as to whether or not antibiotic treatment is necessary based on the specificities of the person's condition. A sample of pus may be sent to the laboratory to ID the strain. Technicians will run tests to determine if the person is infected with MRSA, which is critical in knowing which type of antibiotic to administer to the person. It is critical that a person take the entire course of antibiotics, lest they risk not entirely killing the strain and encouraging antibiotic resistance in the bacterial population. "Superbugs" may be formed if this takes place. Anyone who has been prescribed an antibiotic for a staph or MRSA infection is advised to be extremely diligent in taking the medication for the course of treatment.
Vancomycin is the antibiotic of choice to treat MRSA. However, vancomycin resistance is increasing in MRSA strains, and for that reason, other treatment avenues may be pursued - such as linezolid and quinupristin/dalfopristin.
Risk factors for MRSA
There are a number of risk factors that increase the likelihood of infection by MRSA. These include any skin breaks such as scrapes, cuts and surgical wounds. People with weak immune systems, such as infants, the elderly, and those with cancer, diabetes, eczema, HIV or other chronic ailments are also more susceptible than others. MRSA-caused pneumonia can be spread via droplets produced while coughing.
Certain people may fall victim to the notion that they are "cured" after a few antibiotic doses and decide to stop taking the drug. By exposing the bacteria to low antibiotic doses, they are encouraging its resistance to the drug.
Prevention of MRSA in Hospitals
In a study which sought to determine the best methods for the prevention of MRSA, a control hospital was used which received a new antibiotic treatment policy and an alcohol hand gel policy, while an intervention hospital received the same in addition to environmental screening, chlorine disinfection, and admission screening. The intervention hospital did not do as well in preventing the spread of MRSA as did the control hospital, and various other studies have found that straightforward measures of prevention have been the most effective. Simple control plans that placed an extreme emphasis on hand washing and isolating patients with MRSA saw a 50% reduction in cases of the infection. It is also critical that prevention tactics are cost effective, and do not cost the same or more than treatment tactics.