Epidemiology

Dear Mrs. MRSA, 

My grandmother is moving into a nursing home next month.  I keep hearing about this infection called MRSA that is common in nursing homes.  What is it?  Can I catch it?  What can be done to keep Grandma healthy?

Sincerely, 
Worried in Washington  

Dear Worried,

The good news is that the number of new MRSA infections in the United States are declining.  The number of blood borne MRSA infections - those that can cause the most damage, are declining even more.  Healthcare professionals have learned that better hand cleaning can greatly reduce the number of people of become infected with MRSA.  It is important to practice good hand hygeine when visiting your grandmother, and encourage your family members to do the same.  Choose a facility where the staff gel in and out of the room, wash their hands frequently, and wear protective clothing when visiting rooms where MRSA is present.

What is the distribution in the US?

National Estimated Incidence Rates of Invasive MRSA Infections

Image Source doi:10.1001/jamainternmed.2013.10423

(Washington State has a 22% lower rate of MRSA infections than the national average.)

Are certain parts of the population more affected than others?

• People living in close quarters, such as military, prisons and long-term care facilities, are at a higher risk for contracting MRSA.  Because it can be spread by touching an infected person, or their belongs.  
• People with in-dwelling catheters, central lines, ventilators, or surgery patients have a higher risk of developing complications from MRSA since they are directly exposed to germs.  If your grandmother does need to have one or more of these devices make sure people touching her are using gloves and washing their hands before and after they leave the room.  

What is the mortality and morbidity from this disease?

• It is estimated that 2% of the population carry MRSA in their nose - however, they won’t know it unless they get a lab culture.  
• MRSA is only dangerous if it gets inside the bloodstream.  That is why it is so important for everyone, especially healthcare workers to keep their hands clean, and gloved when working with patients.  
• Deaths related to MRSA have dropped considerably in the United States.  In 2005 about 1100 people died from complications related to MRSA.  In 2011 that number was down to 650 people.  Public health officials attribute this drop in mortality to improvements in hand hygiene as well as greater awareness of the disease.  

Hope that helps clear some things up, Worried.
Next week we will take a question from a reader about how MRSA effects the body (aka pathophysiology).

References
Methicillin-resistant Staphylococcus aureus (MRSA) Infections.  Centers for Disease Control and Prevention website http://www.cdc.gov/mrsa/tracking/index.html.  Updated April 30 2014.  Accessed on April 7 2014.
Dantes R, Mu Y, Belflower R, et al. National Burden of Invasive Methicillin-Resistant Staphylococcus aureus Infections, United States, 2011.  JAMA Intern Med.  2013;173(21):1970-1978.  doi:10.1001/jamainternmed.2013.10423.