by Bob Roehr
Staphylococcus aureus (S. aureus) is a very diverse family of bacteria that is found in nature, humans, and animals. It can cause everything from a common pimple, to food poisoning, to life-threatening pneumonia and blood infections.
Studies have shown that up to a third of Americans can be colonized with staph–it is growing on your skin, particularly in moist areas such as inside the nose–though the rate of colonization can vary greatly depending on geographic region and hygiene. Most people experience no significant health issues from this colonization.
But from time to time, particularly when there is a small break in the protective barrier of the skin, staph can enter the body and result in more serious medical problems. Infection could come from direct contact with the bacteria on another person or indirectly through your own hands that touch a contaminated surface or a patch of your own colonized skin.
Much is not understood about how or why exposure can turn into colonization and/or infection, but the genes of both the bacteria and each person's immune system probably play significant roles in that process, along with other factors.
Methicillin-resistant Staphylococcus aureus (MRSA), the so called "superbug," is the name given to S. aureus that has developed resistance to the methicillin class of drugs. First to emerge was hospital-associated MRSA (HA-MRSA), but within the last decade, drug resistance has been seen in community-acquired MRSA (CA-MRSA), which has no link to hospitalization.
Each of these broad groups contains genetically different strains of the bacteria. Those differences affect virulence and resistance to specific drugs. Evidence also is beginning to emerge that those genetic differences may influence transmission, site of colonization, and the type of disease they may cause.
The vast majority of the 19,000 deaths annually attributed to MRSA occur among the elderly and are associated with hospitalization, surgery, and contaminated equipment for delivering intravenous fluids. Severe disease and death in healthy young adults is rare.
The bacteria can be transmitted through direct skin-to-skin contact as well as through contact with contaminated surfaces. The bug is quite hardy and can survive on surfaces for hours or even weeks, depending on the environment. So it is theoretically possible to acquire MRSA from a toilet seat. It thrives in humid conditions and outbreaks have been traced to gyms, jails, and military barracks.
All of these variable factors make it extremely difficult to nail down a precise set of odds or risks in predicting what will happen when an individual person encounters staph. The outcome could be nothing; or long-term colonization that does not lead to any symptoms of disease; or a pimple; or a skin infection that requires a trip to the doctor; or in rare instances, life-threatening infections of the bloodstream, heart, or "flesh-eating" bacteria.
Active infection generally begins as an inflamed, raised red mark on your skin that looks like a boil or a spider bite. You should worry if it doesn't begin to get better in a few days, and particularly if it develops dark portions indicating dead tissue. That probably will require treatment with antibiotics that the bug is still susceptible to.
The good news is that it's pretty easy to avoid becoming infected with MRSA. Don't share towels at the gym and lay a fresh one down on any surfaces you sit or lay so as not to pick up an earlier person's microbes. Follow your workout, or other activity at a potential transmission point for MRSA, with a good soapy shower. Wash your clothes frequently.
With this study, the list of potential transmission points now includes sex. So shower after it. Sex toys already should be well cleaned to prevent the spread of other sexually transmitted diseases. And given the ease with which MRSA can hang out for long periods of time on clothes and leather it's be a good idea to wash your clothes and consider cleaning your leathers after a visit to a sex club.
You can carry MRSA in your nose or on your skin for long periods of time without having any outward signs of infection. But you can also spread the bacteria from those sites to other parts of your body. Scratching may be enough to cause small breaks in the skin and allow an active infection to get going. So it's important to wash your hands on a regular basis to cut down on the possibility of spreading the bug around.
Basic prudence, not panic, is the way to deal with most MRSA.
