METHYCILLAN RESISTANT STAPHYLOCOCCUS AUREUS
Good, old-fashioned hand-washing: it’s one of the most important health-related things we can do at this time of year. Washing your hands effectively is simple and can be a very effective first line of defense against the antibiotic resistant “superbug” – MRSA.
The latest superstar bug – Methicillin Resistant Staphylococcus Aureus is in the headlines because it has killed young healthy people. According
to the CDC, MRSA occurs most often in patients who undergo invasive procedures,
including surgery, or who have weak immune systems, and are being treated
in hospitals or nursing homes.
MRSA commonly causes serious and potentially life threatening infections
of the blood, surgical site or lungs. The Journal of the American Medical
Association reported in its October issue that MRSA caused 94,000 infections
and nearly 19,000 deaths in the U.S. in 2005.
MRSA - What is it?
First, let’s start back at the beginning:
Bacteria are small and form various shapes: spheres (cocci), curves, spirals
and rods (bacilli) which form a basis for classification. The basic structures
of bacteria include the cytoplasmic membrane, cell wall, capsules, and
intracellular structures. The intracellular structure contains the nuclear
material or DNA. Most bacteria require carbon, nitrogen, water, inorganic
salts and energy for growth. There are four major groups of bacteria:
Staphylococci, Neisseriae, Pneumococci and Streptococci.
Staphylococcus are gram-positive (stain positive) cocci that form clusters
and can survive in both aerobic and anaerobic environments (with and without
oxygen). There are at least 20 species of staphylococci, but staphylococcus
aureus is one of the three most clinically important. Staph aureus is relatively
a common commensal of man: nasal (30-50% of healthy adults), stool (20%)
and skin (5-10%). It is spread by droplets and skin scales which then
contaminate clothing, bed linen and the environment. Staphylococci produce
disease because of their ability to spread in tissue and form abscesses,
produce enzymes or exotoxins, and combat host defenses. Common infections
include skin (boils, impetigo, furuncles, wound infections), abscesses,
osteomyelitis, septic arthritis septicemia and infective endocarditis.
The treatment for these infections includes antibiotics: flucloxacillin (methicillin) or erythromycin. However, staphylococcus aureus has become resistant to methicillin and requires using glycopeptides antibiotics (Vancomycin). This resistance has become known as MRSA (methicillin resistant staphylococcus aureus). It is now an epidemic.
In l980, MRSA accounted for only 2% of all Staph. aureus healthcare-associated infections. Today, MRSA accounts for more than 60% of S. aureus infections. Almost 60% of all staph infections in a hospital intensive care unit are MRSA.
The prevalence of Healthcare-Associated Infections (HAIs) - infections patients acquire during course of receiving treatment for other conditions, has been increasing for the past 2 decades in the US and many other countries. The CDC and the National Nosocomial Infections Surveillance System (NNIS) which collects data from 300 hospitals estimates: 2 million infections a year, resulting in 90,000 deaths, 8 million excess hospital days being added and 11.5 billion dollars paid out plus 9 billion in losses.
Studies indicate the most prevalent HAIs include pneumonia, urinary tract infections, and intravascular-catheter-related infections and surgical site infections.
The rising incidence of HAIs caused by MRSA is of particular concern. MRSA was once primarily a problem in hospitals but is now a growing problem in communities. New research estimates that about 2 million people carry a strain of MRSA in their noses. Most colonized are undetected and not isolated, but once colonized, there is a 30-50% risk of becoming infected. Those colonized with normal strains of staph are at high risk of infection with bacterium, which can lead to conditions ranging from mild skin infections to toxic shock syndrome.
Control and Prevention
MRSA causes more difficult-to-treat and sometimes, more virulent illnesses. The key is to identify colonization at admission in high risk patients. Surveillance cultures used to identify colonization of infected individuals can decrease transmission along with the use of strict barrier precautions
Infection control policies and procedures must be in place and followed. According to a study recently released by the CDC, MRSA is now responsible for more American deaths each year than the AIDS virus. MRSA can be spread through contact with healthcare workers with unwashed hands. Many studies confirm that hand hygiene in most hospitals is at a rate of less than 50% compliance. That means that healthcare workers fail to clean their hands properly over half the time. Every day people die because of poor health care practices and good infection control techniques.
The responsibilities of every healthcare professional and healthcare facility are numerous in order to take an active role in decreasing infection rates and increase compliance with policy and procedure. There are many resources and agencies that provide guidelines and standards for compliance. Each healthcare facility should be in compliance with various regulatory agencies including:
The key to controlling the incidence and spread of MRSA is good hand hygiene and compliance with policies and procedures for infection control and prevention.
Marcia Hardick, RN,BS,CSPDT
NYSACSP Education Advisor