05 July 2008

MRSA colonization - the long-term risk

One of the ongoing puzzles of MRSA's behavior is the significance of colonization, that situation of MRSA living on the skin — or in the nostrils or other locations close to the body's external surface — without causing illness. It's not known how frequently MRSA colonization occurs, for one thing: The long-standing estimate of 1% of the population has been challenged by a number of recent studies.

Another persistent question has been whether the risk of illness and death changes as colonization continues. It has been established that up to one-third of newly colonized carriers will become seriously ill within a year of their acquiring the bug (Huang, SS. et al., Society for Healthcare Epidemiology of America Annual Meeting 2006, abstract 157 - not online that I can find)— but what happens beyond that? Does the risk of illness persist or decrease?

In Clinical Infectious Diseases, the same team that defined the risks of recent colonization report that there are significant risks to long-term carriage as well: 27% of invasive illness in the second year and 16% thereafter, based on a review of 281 patients who were followed for at least one and up to four years at Brigham & Women's Hospital, a Harvard Medical School teaching hospital. These patients become very ill, and in addition use a significant amount of health-care resources:
At our hospital, there are 2–3 times as many hospital admissions involving patients previously known to harbor MRSA than there are hospital admissions of individuals who are newly detected as MRSA carriers each year.
What is the precipitating event that tips MRSA carriage over into MRSA illness? It may be health care. In other words, the long-term carriers do not become ill with MRSA disease and then come to the hospital. Instead, they come to the hospital for some other reason, and the surgery, IV placement, dialysis etc. they receive allows their MRSA strain to slip past the protective barrier of their skin and begin an invasive infection.
We submit that these high risks of MRSA infection among culture-positive prevalent carriers are not only preferentially detected because of hospitalization but may, in fact, be incurred because of the device-related, wound-related, and immunologic declines associated with a current illness.
This raises the question of whether any admitted patient found to be colonized should undergo the routine known as decolonization before any other procedures are performed — and whether institutions and insurance companies will be open to the additional hospital days and drug costs that will represent.

The cite is: Datta, R. and Huang, SS. Risk of Infection and Death due to Methicillin-Resistant Staphylococcus aureus in Long-Term Carriers. Clinical Infectious Diseases. 2008 47:176-81.


Anonymous said...

I was first dx 5 years ago after a hystorectomy and have been told i am colonized. vanc was my treatment iv. since, i am continually sick with one infection or another, I have interstatial cystits, and constantly have uti blah blah blah. But this recent infection wasnt just a regular uti, it was ecoli!!!. My question is this, after having mrsa, does it weaken your imuine system?
Before all my surgeries {unfortunally 12 in all} with mrsa present each amd every time, does it weaken your system? I feel like i can never "feel or get well.
Brenda Sardella

Anonymous said...

I would like to know any answers given to brendalee. I was just dx with mrsa in Oct'08 and I would like to know everything this horrible virus causes and how to protect myself from any further illness. Also, to protect my own family from infection. It is scary to be frightened of your own body.

Anonymous said...

I had been diagnoised with MRSA thru a nasal smear done on admission for a surgery. I also had coded a little over a year ago. I also endured dyalsis and had pseudomosis with several admissions and several surgies. I recently had a blister pop up on my stomach which showed staph methiclillin reistant, my daughter won't let me see my grandchildren until i get tested again. I am not symptomatic I feel fine except I am tired and don't know what to do. They say I am colonized, what can be done about that?

Anonymous said...

There is no proof that MRSA weakens your immune system. Considering the history you gave, my guess is your immune system is weakened by your general poor health with 12 surgeries, etc.
Interstitial cystitis is an inflammation of your bladder that makes you constantly feel like you have a UTI, so be sure to have your doctor culture your urine before you are treated with antibiotics. The more antibiotics you're on, the more likely your MRSA will become resistant to more drugs. (And E. coli is the most common bacteria to cause UTI's, so don't worry about that. Just continue to drink lots of fluids, urinate often, do not use irritating soaps or bubble baths, etc.)

There have been lots of proposed methods of proposed methods of erradicating MRSA colonization. The most common is a medication called bactroban in the nose twice a day. Also taking baths with a small amount of bleach in them 2-3 times a week can help.

Hope this was useful.