Many years ago we were warned about the indiscriminate use of antibiotics. We were told it would create antibiotic resistant diseases. Now MRSA has fulfilled that prophesy in a big way. MRSA (pronounced “Mursa” in the US) is a bacterium which causes infections in humans that are very difficult to treat. MRSA is resistant to many antibiotics, including penicillin; the most widely used antibiotic and the grandfather of many antibiotics such as ampicillin and Oxacillin.
Penicillin went into mass production in 1943. Within four years, microbes appeared which were resistant to penicillin. MRSA, first identified in 1961 in Great Britain by bacteriologist Patricia Jevons (1921-2005), is a mutation of those first resistant microbes. In fact, in 1964, it was discovered antibiotics enhance “the acquisition of new, resistant strains.” MRSA was first noted in the United States in 1968 (in Boston) and is now found around the world.
MRSA has the ability, unlike humans, one scientist explains, to change its genetic make up. MRSA is aided by transduction. Transduction is when DNA from one bacterium is installed in another bacterium with the help of a virus that can siphon DNA from one germ into another, even the DNA of dead germs. This allows MRSA to mutate rapidly, building in resistance to the antibiotics.
When MRSA’s ancestors resisted penicillin using an enzyme, methicillin debuted in 1959 to stop its spread. Within a year it was noted, MRSA used a gene called mecA to survive methicillin. In more recent times, a variant of MRSA lives inside the very cells the body normally uses to kill the intruder—rather like having the hit man to dinner.
MRSA’s ability to adapt to new defenses may be very rapid. Observers at Rockefeller University saw MRSA mutate 35 times in 12 weeks to defeat successive antibiotics given to a patient.
The infection, when it develops, will look like a pimple, boil, rash or spider bite. Pus or other drainage may be present. People may carry the disease for many years without showing symptoms and never-the-less be contagious.
Medical care should be sought if the infection persists or returns or is accompanied by any of the following: “fever, pain, spreading redness, local swelling or heat, or drainage that contains pus or blood.” The attending medical person should be asked to run a MRSA test before any antibiotics are prescribed; if it were MRSA and that strain were resistant to the prescribed antibiotic, it may do more harm than good.
If high fever appears rapidly, if there is severe pain or if swelling of an arm, leg or foot makes bearing weight impossible, immediate medical evaluation should be sought.
Why is MRSA a concern? In 2005 MRSA killed more people in the United States than AIDS did (19,000 deaths from MRSA, 17,011 from AIDS). There were twice as many new cases of MRSA than AIDS in 2005--while more than 94,000 people contracted MRSA, only 45,669 caught AIDS. 2.5 million to 3 million people in the United States are thought to carry MRSA, about two and a half to three times more than people with HIV.
(However, a South Texas study in 2004 suggested a MRSA rate of 360 people per 100,000, which, if true across the country, would mean 11 million people are infected. That figure represented a seventy-two fold increase over the number five years previously. In a Nashville study, 9% of the children tested had MRSA. If that number carried over to the general population, the number of infected people would be twenty-seven million.)
MRSA may be easier to catch than AIDS. There are three main ways to transfer HIV—through a contaminated needle, unprotected sex or mother to child (today typically through breastfeeding).
The MRSA bacteria, on the other hand, can live on a common surface for weeks or months. Anyone who touches that surface (such as a table) may acquire the bacteria. If the bacteria-carrying skin touches another person, MRSA can be transferred to a new carrier.
People shed an entire layer of superficial skin every 24 to 48 hours. If these skin particles contain MRSA, they can contaminate surfaces which the person never touched. Dust is reported to include large numbers of skin particles.
MRSA can live harmlessly on the skin “but even tiny openings, such as a scratched knee or shaving cut, allows it to enter the bloodstream and wreak havoc.” Even a tiny hair shaft can provide entry for the bacteria. Even a bruise, with its collection of blood, is and invitation to MRSA. Or the skin can be brushed against the nose and the bacteria may enter the body through the nasal cavity. A person carrying MRSA in the nose with no symptoms might allow the bacteria to enter the body simply by picking the nose, if doing so damaged nasal cavities.
To appreciate the dimensions of how MRSA can spread, it is useful to compare it to two other diseases. On December 13, 2007, a female passenger with infectious tuberculosis traveled on a commercial airline flight from New Delhi to Chicago. Health authorities are trying to reach the 44 other passengers, scattered over 18 states to urge them to be tested for the disease. The concern is that every time she opened her mouth (whether to cough, sneeze, or talk), tuberculosis-laden droplets were expelled into the air.
MRSA, on the other hand, does not require the mouth to open to be transmitted (though coughing can transmit MRSA if the infection is in the lungs). Any surface touched by the carrier (or upon which the carrier’s skin particles have fallen) can pass the germ to a new person as soon as it is touched. The arm rests in the airplane cabin could contain the germ if a MRSA carrier sat in the seat.
Similarly the armrests of movie theater seats may provide a resting spot for the germ. Athletic equipment can be a source. Shopping cart handles, cans or boxes in grocery stores, used books, library books, magazines in doctors’ offices and money are all potential carriers. As the epidemic becomes better known, handshaking may well fall out of favor.
Pets have been known to acquire CA-MRSA and pass it along to humans who pet them. A collie being used for pet therapy with the elderly in a British hospital was found to have MRSA but though the bacteria was not passed to any of the patients.
The point is a person with tuberculosis sits in a plane and everyone goes crazy looking for the 44 other passengers who may have caught it by breathing the same air. MRSA can live on practically any surface and even infect your pet.
The second example is the stomach flu. Particularly prevalent in winter, it can be passed to computer keys and mice by a carrier. The next person touching those surfaces can acquire the germ. In February 2007 of 380 people in a Washington, DC school, 27% came down with the stomach flu. In a first grade classroom, a computer keyboard and mouse tested positive for the virus, providing a possible vector for the disease.
While this method of transmitting the stomach flu is similar to how MRSA is transferred, MRSA is hardier. The stomach flu virus can survive on a surface for several days whereas the MRSA germ can survive for weeks or months. The flu usually results in several uncomfortable days of severe vomiting and diarrhea. MRSA can be fatal.
To summarize the differences:
Despite MRSA being worse than AIDS in these five categories, the therapist may never have heard of the disease. A Google search turns up 10 times as many hits for AIDS in the United States as for MRSA.
What information is available on MRSA may be inaccurate. The well-regarded 60 Minutes television news show broadcast an episode which said MRSA is “easily treated with antibiotics” in its early stages. In actuality, MRSA is resistant to most antibiotics and if treated with them, thrives into new strains.
The same show emphasized at least twice the “only way you can really get it is through physical contact” with another person. Strikingly, the US Centers for Disease Control disagree with CBS News and assert that MRSA can be transferred through contaminated surfaces and shared items.
MRSA, which looks to be a bigger problem than the well-known AIDS, used to be pretty much limited to hospitals. But in the next chapter, MRSA’s escape into the rest of the world will be examined.