According to the Centers for Disease Control and Prevention (CDC) there were estimated 94,360 MRSA infections (invasive) in the US with approx. 18,650 deaths. No updated data is available from the CDC and MRSA infections have proliferated in the US from 2005-2010. Many hospitals in the US are switching over to the CDC’s NHSN reporting system as before MRSA was reported to CMS ( centers for Medicaid and Medicare).
Other organizations estimate the true numbers to be over one million infected in the US with MRSA and over 100,00 deaths. US hospitals use ICD9 coding and many MRSA infections were not included in statistics. Also, MRSA infections have grown rampant in the community causing an alarming rise in CA-MRSA (community-acquired MRSA).
85% of all invasive MRSA infections were from healthcare facilities with patients contracting infections after their stay ( two-thirds) and one-third while in the facility.
14% of all infections occurred in the community with no exposure to healthcare and this number is continuing to grow.
MRSA strains from the community (CA-MRSA) are entering healthcare facilities within the US and comingling with HA-MRSA strains.
In a 2003-04 study, approximately 29% of the US population was colonized with staph. aureus and 1.5% with MRSA. But studies from hospitals that are conducting universal screening upon admission of all patients have seen colonization of MRSA as high as 12%.
MRSA infections and colonization has steadily increased over the years and in 1974. 2% of all staph. aureus infections were MRSA, 22% in 1995 and in 2004 it was 64% with an estimate of over 70% of all staph is now MRSA. In the community, it is estimated that 60% of all skin and soft tissue infections that doctors treat are MRSA infections.
Costs of MRSA and Hospital-Acquired Infections:
The economic cost created by hospital-acquired infections has skyrocketed in the past decade, accounting for up to $45 billion (Scott – 2010). This problem is only compounded by the recent upsurge in drug resistant bacteria and community-acquired infections. The increased incidence of these infections and the longer hospital stays and worse patient outcomes associated with them are the key drivers behind the proliferation of costs. Byway of Medicare and Medicaid, the government bears nearly three-quarters of the economic burden of MRSA infections due to their over-representation in the elderly and indigent (Healthcare Cost and Utilization Project – 2008). As Americans age and healthcare is extended to the majority of the uninsured, the government will inevitably assume these costs.
The drastic rise in hospitalizations in the past 15 years has mirrored the increase in antibiotic resistance. With nearly 5% of hospitalized patients contracting an infection (Klevens – 2007), the problem isn’t given the importance it deserves. MRSA highlights the current struggle with drug-resistant infections. MRSA infections compared to their non-resistant equivalents, MSSA infections, are associated with double the cost, length of stay and mortality (Davis – 2007). These infections prey upon the elderly and young, mainly due to their suppressed immune systems. Both of these age groups are more likely to end up in the ICU due to their infections and the ICU cost per day is more than twice that compared to normal hospital stays.
In 2005, MRSA cost the healthcare system up to an extra $9.7 billion, even without taking into account indirect costs related to patient pain, illness, and time spent in the hospital (Klein -2007). The large number of MRSA infections takes a vast toll on our healthcare system and ineffective treatments only exacerbate the problem. A recent study found that nearly one-fourth of all initial treatments for skin infections fail and the costs associated with failed therapy are twice as much, while mortality is increased three-fold compared to effective treatment (Zilberberg – 2009). These figures do not even take into account time lost from work and an inferior quality of life for patients with infection.
Infections Control and Preventability
The epidemic of healthcare-acquired MRSA infections and other healthcare-acquired infections are not isolated to one particular region but are prevalent throughout the world. Many of these infections are preventable through better infection control. Every year in the EU over 4 million patients acquire a healthcare-acquired infection. The number of deaths occurring as a direct consequence of these infections is estimated to be at least 37,000 and an additional 111,000 die as an indirect consequence of the hospital-acquired infection. Approximately 20–30% of these healthcare-associated infections are considered to be preventable by intensive hygiene and control programs (European Centre for Disease Prevention and Control). Worldwide campaigns and public policy changes will be required to reduce the number of preventable healthcare-acquired infections.
Many simple and low-cost control measures such as hand washing of hospital personnel have been shown to significantly reduce hospital-acquired infections. Infection prevention and control is based on: prevention of cross-transmission of pathogens; prevention of bacteria causing infections when normal barriers are breeched; and prevention of resistant pathogens by inappropriate antibiotic use. Unfortunately, many healthcare-acquired infections are not avoidable in real-life hospital conditions, because of the underlying illness of the hospitalized patient, the invasive procedures to which patients sometimes have to be exposed in order to survive (e. g. mechanical ventilation), and the potential pathogens that all humans carry and that may cause severe infections if normal host defense mechanisms are breeched. The question is what represents the irreducible minimum, for healthcare-acquired infections as such, but also for the cross-transmission of resistant or more virulent healthcare-acquired pathogens and for the selection of multi-resistant micro-organisms (such as MRSA) by antibiotic use. The landmark SENIC study found that nosocomial infection rates can be reduced by 32% through intensive infection control and surveillance programs (European Centre for Disease Prevention and Control). A recent study by Jain (2011) in US VA hospitals showed that stringent infection controls lowered MRSA in the ICU by 62% over a two and half year period.
The high cost and human suffering caused by healthcare-acquired infections drastically outweighs the low cost of infection control programs. Yet, even with the large number of positive findings from infection control studies, the US and most developed nations have not implemented them nationwide. With the CDC’s severe underestimation of the MRSA epidemic, the public is left with a fragmenting picture of the true problem. A nationwide surveillance system for MRSA infections needs to be implemented to document the correct number of infections. In contrast to the CDC’s reported numbers, the current number of MRSA-related deaths in the US is reported to be over 90,000 people annually (http://www.mapmrsa.org/mrsa_facts.html). With the death and suffering toll increasing there is no time to waste implementing these infection control and surveillance programs.
Future Concerns of MRSA
The increasing annual burden of MRSA infections is only exacerbated by the lack of novel antibiotics in development. Vancomycin, the gold standard for MRSA infections, is used to treat the vast majority of MRSA infections. Vancomycin’s usage has increased dramatically in the past decade due to the increase in the number of MRSA infections. Mirroring this increased vancomycin usage is the increase in MRSA strains with reduced susceptibility to vancomcycin. Success rates in MRSA infections with reduced susceptibility to vancomycin have been found to be over 5-times lower than infections with bacteria that are susceptible to vancomcyin (Sakoulas 2004). Between 2005 and 2009 there has been a nearly 4-fold increase in the frequency of MRSA isolates that have reduced susceptibility to vancomycin (Hawser 2011). With the usefulness of the main therapy for MRSA infections declining by the day, the public needs to speak out and institute antibiotic stewardship programs as well as encourage development of new antibiotics.
Contributor and author – Brendan Hannah