Antibiotic Resistance - Background

When antibiotics are ineffective

ESKAPE pathogens

Antimicrobial resistance is recog-
nized as one of the greatest threats
to human health worldwide. The ESKAPE pathogens:

• Enterococcus faecium,
• Staphylococcus aureus,
• Klebsiella pneumoniae,
• Acinetobacter baumanii,
• Pseudomonas aeruginosa,
• Enterobacter species

cause the majority of hospital infec-
tions. Resistant ESKAPE bacteria
are not killed by the antibiotics that
have been so beneficial to humanity.

Concerns about acquired bacterial
resistance towards antibiotics are
high in the Nordic countries, the
Netherlands and Switzerland.

When other developed countries
want, or have to, acknowledge the
problems of resistance, the market
for alternative wound treatment
therapies is expected to grow
significantly.

MRSA - Methicillin Resistant Staphylococcus aureus

Staphylococcus aureus colonizes skin in about 30% of healthy humans. The bac- terium is very adaptive to changing environments. MRSA accelerated its global appearance with an especial- ly invasive form that spread rapidly from Australia around 1960. Due to its resistance towards antibiotics, MRSA today cau- ses healthcare associated infections worldwide.
	MRSA (image: wikimedia)

Risk groups

MRSA is normally not harmful to healthy people. When bacteria are
introduced to blood stream, or in people with suppressed immune
system, the infection may become life threatening

Common environments for MRSA spreading are: close contact areas
like hospitals, elderly at homes, children at day care and athletes in
contact sports.

Also contacts with farmed pigs appear to involve elevated risks.

Suffering and Costs

16% of all Hospital Acquired Infections in USA were caused by resistant bacteria (NHSN 2008). Resistant bacteria increase mortality by 50%, and the cost for each infected patient was 2008 $ 21 000 [Roberts et al., Clinical Infectious Diseases 49 (2009) 1175-1184].

The total annual extra costs for resistant infections in the US healthcare system during 2008 has been estimated to $ 20 US billion (= $ 20 milliard) [IDSA], [CDC 2013].

Disinfection at home

At home, disinfectants other than antibiotics are sometimes used to kill bacteria in
smaller wounds. Such antimicrobic substances are not used in open wounds be-
cause they harm both bacteria and the patient's own tissues to the same degree.

When wound tissues are harmed, both wound healing time and probability of scar
formation are increased.

Wound healing experts advocate use of only saline solution or pure water in
cleaning of wounds.

Cure and prevention of MRSA

As common antibiotics are not effective, the patient's own immune system is primarily
relied on for curing. Health care professionals advocate prevention by sanitation and
manual cleaning.

A possible treatment of MRSA infections are injections using "the last resort"
Vancomycin. Due to fear of further development of resistance, however, the
treatment is used only under urgent circumstances.

Prevalence map

The figure above shows proportion of MRSA in parts of the world during
2006 [Grundmann et al., Lancet 368 (2006) 874-885].

The prevalence of MRSA is low in northern Europe and in the Nether-
lands, while it is high e.g. in Mediterranean countries, USA and Brazil.

Prevalence change in USA

The figure at left shows hospital stays with MRSA infections in
USA 1993-2005 [AHRQ, Healthcare cost and utilization project,
Nation-wide Inpatient Sample, 1993-2005].