6.3.2. Antimicrobial resistance and healthcare-associated infections
Resistance to antibiotics is a large problem in the
community, but even worse in healthcare settings. Hospitals, especially
intensive care units often have their own resident bacterial flora, which are
often highly resistant to those antibiotics that are commonly used locally.
Although not all health care associated infections (HCAI) are caused by
resistant bacteria, a very large and increasing proportion is, intertwining the
two problems of antimicrobial resistance (AMR) and HCAI.
Antimicrobial resistance and antibiotic consumption
AMR is one of the most serious public health problems both
at globally and European level. If the present rapid negative development is
not halted, mankind will soon lose one of its most important weapons against
Resistance has also evolved against bacterial, viral (e.g.
HIV, influenza), parasitic (malaria) and fungal infections, making AMR the most
serious of all communicable disease threats.
The bacterium that has received prime attention is
methycillin-resistant Staphylococcus aureus (MRSA). A larger and larger
proportion of all invasive S. aureus infections are caused by MRSA. Data on AMR show
that in general the problem is somewhat lesser in Northern Europe (Scandinavia
and the Netherlands), and more serious in the Southern and South-Eastern parts
of the Union. Intra-country variation is also reported to be significant and
deserves attention, in view of the general increase in MRSA, which occurs
throughout Europe, and includes countries with high, medium, as well as low
baseline figures (figure 6.1). However, two countries (Slovenia and France)
have succeeded at significantly reducing the proportion of MRSA, thus
demonstrating that this MRSA pandemic may not be irreversible.
Proportion of methicillin-resistant isolates over total S. aureus blood stream
infections in selected EUGLOREH Countries.
For most other bacteria and virus under EU surveillance
the overall trend is also very worrying. AMR is a particular concern when it
comes to the global killer diseases TB, malaria, HIV and pneumococcal
infections. AMR data are currently collected via several surveillance networks,
whilst coverage across and within countries shows a lot of variation.
Furthermore, there may be big regional differences within countries, which are
not visible the way the data are presented. A prerequisite to be able to follow
the trends of resistance patterns is that the methodology for sensitivity
testing is the same in all laboratories and that it is reliable and quality
For other bacteria under EU surveillance, such as the
intestinal bacteria enterococci, E. coli, Klebsiella pneumoniae, Campylobacter, Salmonella and Pseudomonas aeruginosa, the overall trend is
also worrying. For Streptococcus pneumoniae (pneumococcus), the most common
bacterium causing respiratory tract infections and a major microbial cause of
death in young children, the picture is more mixed, with decreasing
penicillin-resistance in some highly endemic countries and increasing
resistance to penicillin and other antibiotics elsewhere. Resistance is mainly
confined to a few serogroups, all of which have been included in the recently
introduced conjugated vaccines. This suggests that vaccination of young
children would represent an effective additional means of controlling
antibiotic-resistant pneumococci in Europe.
The emergence of strains resistant to the two most
effective agents against TB, isoniazid and rifampicin, (multi-drug resistance,
MDR), as well as to other second line antibiotics (extensive drug resistance,
XDR), poses a serious challenge to TB control today. Multi-drug resistant TB
(MDR-TB) was present in 15–20% of cases reported by the Baltic Republics
(Estonia, Lithuania and Latvia), but ranged from 0–6% in the rest of the
countries. MDR is more frequent in previously treated cases, and in foreigners,
especially those originating from the former Soviet Union. The wider
participation of countries in surveillance of drug resistance is needed to
ensure a better monitoring of this public health concern.
A key factor in the development of AMR is the
inappropriate utilization of antibiotics. Since their discovery, antibiotics
have revolutionised the way we treat patients with bacterial infections and
have significantly contributed to reducing death and morbidity from bacterial
diseases. They are also absolutely essential for modern medicine. Common
procedures such as transplants, chemotherapy for cancer, and even orthopaedic
surgery could not be performed without the availability of potent antibiotics.
Unfortunately, they have also been liable to inappropriate use, often
unnecessarily prescribed for viral infections. Similarly, when diagnoses are
not accurately made, more often than not broad-spectrum antibiotics, i.e.
antibiotics that kill a large proportion of the normal bacterial flora and not
only the disease-causing bacteria, are prescribed. These examples of the misuse
of antibiotics promote the emergence and selection of resistant bacteria.
Data on antibiotic consumption are difficult to obtain and
come from different sources. Yet in most countries it has been possible to
differentiate antibiotic usage in hospitals and outpatient settings. It has
been shown that the amount of antibiotic consumed per inhabitant varies
three-fold between Member States, though it is difficult to understand why.
As for AMR, antimicrobial use shows a general gradient
from low use in Northern Europe to higher use in Southern Europe; the highest
user prescribing three times more antibiotics than the lowest. Additionally,
there are marked differences in the type of antibiotics that are used. In the
Nordic countries, a larger proportion of total use is still represented by
older narrow-spectrum antibiotics, whilst newer broad-spectrum classes are
seldom used on outpatients. This is the most likely reason for the low levels
of resistance to the newer antibiotics classes in these countries. A consistent
association between the level of use of specific antibiotic classes, and
resistance to these classes has been reported.
Control tools and policies
Control tools include surveillance, and other specific
measures for primary prevention.
AMR is a phenomenon that affects most, if not all,
pathogens of importance to human health; therefore, the demands on effective
surveillance systems are immense. The current EU surveillance networks are
focused on a few key pathogens, but most pathogens are not covered and the
system relies on voluntary reporting from a limited number of laboratories,
sometimes disguising regional differences within countries. Ideally,
surveillance of AMR should work on three levels:
trends of resistance in major important pathogens;
outbreaks and/or spread of different ‘problem bacteria’; and
novel ‘super strains’ where each isolate requires immediate and forceful
Today, EU-level (and national) surveillance only covers the first of these
three levels. Further developing surveillance of AMR is therefore a priority.
Considering the mechanisms behind the emergence of AMR,
the EU Health Council has provided recommendations to Member States to
establish national strategies to contain AMR: use them in the correct way; and
block the spread of resistant strains between people. There are many examples
from across Europe of good practices and success stories.
HCAI also referred to as nosocomial infections, are a huge
public health problem in Europe. On the basis of recent surveys, the total
number of patients acquiring a HCAI in the EU25 every year can be estimated at
3 000 000, and approximately 50 000 deaths occur every year as
the consequence of the infection. Of 87 000 patients staying more than two
days in an intensive care unit, 7.2% acquired pneumonia, and 3.1% acquired
The most frequent infections are urinary tract infections
(28% of all HCAI), followed by respiratory tract infections (25%), surgical
site infections (17%), bacteraemia (10%), and others (including diarrhoea, with
the increasingly important Clostridium difficile). Other major nosocomial pathogens
are methycillin-sensitive Staphylococcus aureus (Figure 6.1), Pseudomonas aeruginosa, enterobacteriaceae (E. Coli, Enterobacter, Klebsiella), Enterococci, fungi (Candida, Aspergillus), and Acinetobacter.
Control tools and policies
Approximately 20–30% of nosocomial infections are
considered to be preventable by an intensive infection control programme that
includes surveillance. National or regional surveillance is mostly performed in
the context of a surveillance network of hospitals, whereby individual rates
are compared to those of other participating hospitals and services as a
measure of own performance using risk-adjusted infection rates. Since the
latter requires the collection of risk factors and the involvement of
clinicians, infection control staff and microbiologists, HCAI surveillance is
labour-intensive and therefore targeted at specific high-risk populations (such
as intensive care patients) or infection types (surgical site infections,
bloodstream infections). Furthermore, several EU Member States still do not
have a national surveillance network for nosocomial infections, since setting
up such a programme usually involves important political decisions, specific legislation
and a financial investment at both national and hospital levels in order to set
up or reinforce infection control programmes with surveillance.