MRSA – Colonization vs. Infection

One aspect of MRSA that is often not fully understood by the public is the concept of colonization vs. infection. Staphylococcus aureus is a bacteria that lives normally on human skin surfaces – in fact 40% of us have the little guys all over us right now as we sit here in front of our computers. MRSA, which is simply an antibiotic resistant strain of Staphylococcus aureus, can also live on our skin for long periods or even permanently without us ever knowing it. This is called colonization, and depending on the population group/risk profile most studies show that 5-10% of us are carrying MRSA around with us wherever we go. As far as sites of colonization this bacteria can live on virtually any skin surface, but they really love the warmest, dampest, darkest areas they can find including the nose, throat, armpits, and various sites “south of the border”. It is widely accepted in the medical community that the nose represents the primary reservoir of S. aureus/MRSA colonization in humans, with the throat emerging as another important area and all other sites considered secondary.

When a hospital discloses MRSA rates, or the media reports on MRSA incidence, they are almost always talking about infection rate as opposed to colonization rate. Active infection occurs when a bacterial strain undergoes uncontrolled growth. When the body attempts to mount a defense against this overgrowth you begin to see the typical, well known symptoms of infection including redness, pain, fever, etc. Infection can be localized to a specific area such as a wound, cut, or burn. More concerning, is when an infection spreads as a result of bacteria entering the blood supply and continuing to grow while circulating throughout the body. This is known medically as “bacteremia”, and is the most serious and deadly form of infection.

Some doctors and scientists think of colonization and infection not as distinct conditions, but as two points on a sort of continuum. While people colonized with MRSA regularly live happily unaware for many years, studies have proven that they are far more likely to develop an MRSA infection at some point than those not carrying the bug. Furthermore, asymptomatic (ie. non-infected) MRSA carriers can easily pass this bacteria on to others through direct contact or even just by living in the same environment. This is especially scary because while your immune system may do just fine dealing with 1,000,000 MRSA bacteria per square inch in your nose, your 80-year old grandmother, 6-month old infant, or cancer-fighting spouse may not be so lucky. This is exactly the reason why initiatives are popping up all over aiming to have all patients screened for MRSA prior to admittance into hospitals. There are simply too many immunocompromised patients, too much movement, and too great a risk within those walls to allow free passage of bacteria living silently on unaware carriers.

So next time you read a news story about MRSA, take a second to determine whether the issue being reported is one of colonization or infection. After that, think about how one is associated with the other and where the most logical point is to attack the problem. I think you’ll find yourself ending up at the old “treatment vs. prevention” argument, and we all remember what our mothers used to say about an ounce of prevention and a pound of cure…

Related Posts Plugin for WordPress, Blogger...

16 Responses to “MRSA – Colonization vs. Infection”

  1. Marlene says:

    I am 62 yrs have ‘RSD’, chronic tachecardia , diabeties ,rumatoid arthritus ,and history of reoccurring lupus. My immune system dr. said was no good. My mother had staph for 3 months and now being treated for MRSA in hospital all resulting from Charcot’s foot surgery in April and this is Sept. Should I be tested some how before I spread this ‘thing’. I also have a newborn grandson and live with my 10 and 13 yr old grands. How can I be checked? I do not have any infections to culture right now. The staph germ we do not know how she got it. It grew into MRSA and they called her Septic. Vancomicin isn’t used this time (2)different drugs are used. I believe JESUS has helped my 83 yr. old mom or she whould have quit a while back.

  2. Joyce says:

    When a family member has an open out break of MRSA how do we prevent the other members of the family from getting the infection? How limited should our movement be in the community? i.e. the work place, market, church. What about hobbies involving gardening, painting, sewing/ How do family pets play into this condition?

  3. Stephen King says:

    I had a bad infection of MRSA, doctors were so concerned they were talking about the possibilities of amputating my leg to prevent death. After I came hoe (2weeks in hosp.) I was on Zyvox for a month. In this process I had a severe craving for yogurt. Can anyone tell me why? I recovered and am doing fine now.

  4. Cale Street says:

    Hi Marlene – very sorry to hear about your condition and your mothers ongoing infection. The “septic” diagnosis given by the doctors means that the infection is internal (in her blood) and she is experiencing symptoms caused by her immune system trying to respond to the bacteria. I’m sure the doctors are giving her the best antibiotics and overall treatment available – she sounds like a very strong woman so hopefully she can overcome this.

    If you have no active infections that are MRSA positive, that is a good sign. Given your history of immune-related disorders, you may be more susceptible to infection down the road. Make sure to take regular precautions like frequent handwashing (especialy after visiting your mother in the hospital) and talk to your doctor about your risk factors as well as about concern for your grandchildren. Getting swabbed to see if you are carrying MRSA at this point might be a good idea, but again follow the advice of your doctor on this.

    Good luck to you both, and I hope my future posts can help you better understand MRSA as you deal with it in your life…

  5. Cale Street says:

    Hi Joyce – When you’re being treated for an active MRSA infection your doctor will likely have you take several precautions to stop the spread of bacteria in your household. Part of this will involve washing clothing, sheets, etc in your house with a good antibacterial detergent. Besides actively treating you for the infection itself, you may also be asked to shower with special soap/shampoo containing an antibacterial chemical called chlorhexidine. All of these measures are designed to limit your potential to spread MRSA to your family.

    As far as limiting movement outside your house in the community – best to follow your doctors advice. That advice will probably depend somewhat on the seriousness of your infection and your ability to heal properly while still performing your daily routine. Careful frequent handwashing with antibacterial soap as well as avoiding direct physical contact with others out in the community are obvious precautions you should take to avoid spread outside your house.

    Great question about your pets. Several recent news stories have been published suggesting that pets can be colonized with MRSA just like we can. Unfotunately its still not clear whether humans and pets pass MRSA back and forth, and if our pets being colonized puts our family at greater risk. For now probably the best thing you could do if you’re concerned about a pet is to bathe them as well with an antibacterial shampoo while performing the other precautions defined above.

    Hope this helps! As always, follow doctors advice above all…

  6. Susan T says:

    I was diagnosed with a osteomylitis which was MRSA in my great toe. Very painful-a blade of grass falling on my toe sent me into tears. Treated with vancomycin for 11 weeks, IV. Fun times, yes? Anyway, through reading discussions online, it seems I will always be susceptible to these infections now. To the best of your knowledge, is this true? I know I could have lost my toe, to say the least but am I going to have to be doubly careful forever? I am a klutzy person and it’s not uncommon for me to fall and get scraped up a bit.

  7. Due Soon says:

    We have been fighting MRSA skin infections on my 2.5 year old daughter for 10 months now. It took six months to get her boils diagnosed and some more time to realize how dangerous MRSA actually is. I am due to have another baby in the next couple of weeks and am terrified that the baby will get an infection from the MRSA but neither my doctor nor my daughter’s pediatrician think there is a great risk. In the meantime, we are undergoing an aggressive and persistent disinfection regime in our home. Our daughter’s bum is a painful mess, and we are hesitant to get more antibiotics as the boils do heal on their own, but constantly recur.

  8. Had mrsa too says:

    Hi there

    I broke out with a boil pm my bum after sharing a toilet seat with an infected person. You can use 90 percent alcohol to clean and disinfect areas successfully. There also is prescription ointment and soap that is advised

  9. dede says:

    If a person has bilateral knee and hip replacements and the last trip to the hospital indicated a positive nasal swab for MRSA, does this indicate that person will most likely develop this type of infection problem or sepsis at some later time? Is it always contagious? Are taking a couple antibiotics prior to dental cleanings, a satisfactory practice to keep from getting sepsis that way too.?

  10. Tony says:

    My wife had a stroke and later a surgery – then later had mrsa in her lungs. The doctor gave her anti-biotic meds. They worked for 3 day then she became resistant to the meds so I read on the internet that garlic and oregeno kills the mrsa bacteria, go I gave her 3 capsules each 3 times a days (now you will have to find out what you can tolerate). I also had a nebulizer, so I added 3 drops of oil of both garlic and oregeno in the salin solution – so she could breath it into her lungs. The reason I did this is because she the other anti-biotics conflicted with the other meds she was on. Anyway after just a couple of days she responed well – then after 2 weeks she was completely clear of any symptoms.

  11. mike h says:

    Hi all .i have had MRSA THEN IT WAS CLEARED UP. NOW I HAVE V.R.E. i cant find out NOTHING on what it does to the body. My email if anyone has any info.i was in a va hospital for 6months and 1day. I was on a IV antibiotic most of the time. Thank you

  12. Mac Wildstar says:

    I am looking for information as to how dangerous it is to have someone with MRSA living in your home.

    I am a Veteran, who underwent Quad Bypass surgery at the VA hospital in Ann Arbor Michigan. Prior to undergoing surgery I was tested and found to be colonized.

    I still have edma in my lower legs with fluids escaping (open wounds) that I keep covered.

    My question is this: How much of a risk am I to other people in my home?

    I currently live with a relative while I look for an apartment, now that I am able to be on my own again after the surgery. And I may have to look at a roommate situation. However, if I am a threat medically, that may not be possible. So that is why I ask.


  13. galen says:

    Per my daughter’s dermatologist-taking a bath twice a week with 1/2 cup bleach added to it is very good for treating skin infections

  14. Susu says:

    Our family is getting together next weekend for Christmas. The niece that is hostess was ex last week with MRSA in her throat and been on antibiotics . Her children have had Streph Throat , she said her doctors have told her that no one is in danger that everyone has mrsa . This is true but everyone is not active and have kids with Streph too. I had a HORRIBLE case of MRSA about 12 years ago and had pure holes on my arms. I have been told both ways …. Ami I more prone to catching anything from her? Her doctor said unless you were making out and kissing would she be contagious . She has a 4 month olld baby and she said he was fine.

    I am concern should I. It attend or would I be safe with great hand washing and no hugging .
    my other neice has a 6 weeks preemie that weighs 2 pounds and was born at 25 weeks at 1.5 pounds . They are concern about attending too ,

    Please advise . Thanks

  15. Greg Pond says:

    As you well know MRSA can be very serious and so we think you are right to raise the concerns that you have. However, since we are not physicians we cannot give you medical advice. What we can do is give you the benefit of our experience in the field. You would then bring our thoughts to the attention of your physician and that way your decision to go to your niece’s house over Christmas would be as informed as possible.

    To begin with not everyone has MRSA: only about 1 – 3% of the population are carriers, versus about 33% of the population that carry staph, i.e., methicillin susceptible (vs. resistant) staphylococcus aureus. A carrier is someone who has the bug on or in them but has not been made sick by it.

    But the main point to discuss with your physician is this: MRSA is spread through contact with the bug. If it’s in someone’s throat it would be transmitted through saliva; thus by kissing, or sneezing or even rough coughing. So you can get it directly from the affected person, or indirectly: they sneeze or cough onto a surface which you later touch.

    A related question is, where did your niece get it from? Some place in the house? Someone in the house who is just a carrier but not infected? In other words, you could conceivably catch from anyone (whose MRSA wouldn’t necessarily be in their throat), or anything in that house.

    Picking up MRSA from a surface – typically by touching it with your hand – raises the issue of good hand hygiene. Note that for hand washing to be effective a certain technique is required. Here’s a link to a video from the US Centers for Disease Control and Prevention that shows you how to do it properly:

    People who have had MRSA are at a greater risk than others for getting it again but that refers to your own MRSA reemerging; typically because the medication hasn’t killed all the bugs and they regrow, or because you pick it from a surface in your house that you contaminated before you went for treatment. Since your experience with MRSA was 12 years ago, this should not apply to you.

    However, some people are more susceptible to MRSA than others, namely, those with an immune system that’s not as strong as a healthy adult’s. Thus, the elderly, newborns, or someone who is sick, are considered more vulnerable than others. Since you mentioned there are two infants in your family that may be at the Christmas gathering I’m sending you a link to some research on MRSA and neonates. Your physician may find it useful:

    Thank you for your email. Your concerns are certainly valid. We hope that our thoughts on the matter will help you make a more informed decision and, most importantly, keep you and your family healthy.

  16. Suzanne Armstrong says:

    I was diagnosed with stap +1 MRSA and treated with gentamycin eye drops for one week. Went for a one week follow up check up and still has some drainafe in my right eye and is red, not swollen. On my second week of eye drops. Should I check with my PCP MD for possible oral antobiotic or seenan infectious specialist?

Leave a Reply

Staypressed theme by Themocracy