From Our 2011 Archives
Doorknobs May Be 'Reservoirs' for MRSA
Researchers Track Spread of MRSA in Homes With Contaminated Household Items
By Charlene Laino
Reviewed by Laura J. Martin, MD
Sept. 19, 2011 (Chicago) -- If a member of your household has a drug-resistant staph infection, be aware that doorknobs, light switches, and other seemingly harmless items may serve as reservoirs for the bacteria to multiply and spread.
People with MRSA (methicillin-resistant Staphylococcus aureus) who live in homes where such common items test positive for the same strain of MRSA are about five times more likely to spread the bacteria to another household member, a study of nearly 300 homes suggests.
Staph, including MRSA, is a common bug that lives on the skin or in the noses of about 40% of people without causing harm, says researcher Justin Knox, MPH, a PhD candidate in the department of epidemiology at Columbia University in New York City.
But previous research by the same group suggests that contamination of household items is associated with an increased risk of recurrent MRSA infections, Knox tells WebMD. "Environment appears to play a role in [MRSA spread]."
The study also showed that having a child age 5 or younger or having a pet in the home doubles the risk of transmitting staph to another household member.
Knox presented the findings here at the 51st Interscience Conference on Antimicrobial Agents and Chemotherapy.
MRSA on the Rise
A 2005 study showed that the annual rate of community-acquired MRSA infection -- cases occurring in people with no recent hospital or nursing home stays -- ranged from 18 cases per 100,000 people in Baltimore to 26 cases per 100,000 people in Atlanta.
Since then, there has been a dramatic increase in cases, and studies suggest that community-acquired infections are often contained within households, according to Knox's colleague, Anne-Catrin Uhlemann, MD, of Columbia University.
However, the source of these infections has been unclear.
So Knox and colleagues compared the households of 146 people who came to the hospital to be treated for community-acquired MRSA infections to a comparison group of households of 145 dental clinic patients.
Patients completed a questionnaire about themselves and household members. Also, nasal swabs were collected from consenting household members, and household items were swabbed. Swabs were cultured for staph bacteria.
Among the findings:
Minimizing Your Risk of MRSA
So what should you do to minimize the risk of MRSA spreading in your household?
If you have a young child, make sure he or she follows these recommendations.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.
SOURCES: 51st Interscience Conference on Antimicrobial Agents and Chemotherapy, Chicago, Sept. 17-20, 2011.Justin Knox, MPH, PhD candidate, department of epidemiology, Columbia University, New York City.Anne-Catrin Uhlemann, MD, division of infectious diseases, Columbia University, New York City.Catherine Bennett, PhD, head, School of Health and Social Development, Deakin University Australia, Burwood, Victoria, Australia.Fridkin, S. New England Journal of Medicine, 2005; vol 352: pp 1436-1444.CDC web site. ©2011 WebMD, LLC. All Rights Reserved.