At least one of these patients is infected

Practical Patient Care: Your latest report warned that around 3.2 million patients across Europe each year acquire at least one healthcare-associated infection. How did the report arrive at this figure, and what were its other key findings?

Dr Marc Sprenger: The report is based on data submitted to the European Centre for Disease Prevention and Control (ECDC) from a total of 273,753 patients in 1,149 hospitals. Of these, 231,459 patients from 947 hospitals were included in the final European sample for analysis. Data from a single ward was collected on a single day. The total time frame for data collection for all wards of a single hospital was 12 days on average; the median was nine days.

The survey confirms that healthcare-associated infections (HAIs) represent a major public health problem and a threat to European patients: ECDC estimates that, on any given day, about 80,000 patients - that is, one in 18 patients - in European hospitals have at least one HAI. Overall, this amounts to an estimated total of 3.2 million patients with a HAI in European hospitals each year; this represents an overall HAI prevalence percentage of 5.7% (the prevalence percentage varies by country, from 2.3 to 10.8%).

In order to reach the estimate that 3.2 million patients contract an HAI each year, prevalence of HAIs was converted to an incidence of HAIs by means of the Rhame and Sudderth formula. Although this method is generally accepted as the reference, estimating incidence from prevalence surveys inevitably has many limitations, which is why the 95% confidence limit around the 3.2 million-patient estimate is very large, ranging from 1.9 million to 5.2 million patients.

Some of the report's other key findings were:

• The prevalence of HAIs was the highest among patients admitted to intensive care units (ICUs) in these European hospitals, where 19.5% of patients had at least one HAI. The most common types of HAI in these ICUs were respiratory tract infections and bloodstream infections.
• The increasing spread of carbapenem-resistant Gram-negative bacteria in several European countries and the persistent presence of other well-known hospital pathogens, such as MRSA and Clostridium difficile, were confirmed in this report.
• The survey also confirms the large proportion of patients that receive antimicrobial agents while being hospitalised. ECDC estimates that more than 400,000 patients - one in three patients - receive at least one antimicrobial agent on any given day in European hospitals.

What were the most commonly reported infections, and roughly what proportion was drug-resistant?

Of a total of 15,000 reported HAIs, the most frequently reported types were respiratory tract infections (pneumonia represented 19.4% of HAIs, and lower respiratory tract infections 4.1%), surgical site infections (19.6%), urinary tract infections (19%), bloodstream infections (10.7%) and gastro-intestinal infections (7.7%), with Clostridium difficile infections representing 48% of gastro-intestinal infections and 3.6% of all HAIs.

Selected antimicrobial susceptibility testing (AST) results were available on the day of the report for 85% of microorganisms reported in HAIs:

• meticillin resistance (meticilin-resistant Staphylococcus aureus or MRSA) was reported in 41.2% of Staphylococcus aureus isolates with known AST results
• vancomycin resistance was reported in 10.2% of Enterococcus species isolates
• third-generation cephalosporin resistance was reported in 33.4% of all Enterobacteriaceae isolates, and was the highest in Klebsiella pneumoniae isolates
• carbapenem resistance was reported in 7.6% of all Enterobacteriaceae isolates, and was also the highest in Klebsiella pneumoniae isolates
• carbapenem resistance was reported in 31.8% of Pseudomonas aeruginosa isolates and in 81.2% of Acinetobacter baumannii isolates.

Why have HAIs become such a problem throughout the EU? What dangers do they pose to the wider healthcare community, and what are the primary areas of concern?

HAIs do not represent a new public health issue and have existed since patients were first hospitalised. The problem represented by these infections has, however, been receiving more attention in recent years, particularly in the EU. In 2008, for instance, the ECDC estimated that the number of patients acquiring a HAI in European hospitals was 4.1 million each year - a number that is still within the 95% confidence interval calculated for the current ECDC point prevalence survey.

"The wider healthcare community - nursing homes and long-term care facilities - is also affected. Based on an EU-wide survey performed in 2010, the ECDC estimated the number of HAIs in long-term care facilities in the EU at 4.3 million a year. Patients discharged from hospitals and taken care of at long-term care facilities, or even at home, can still develop HAIs.

When patients from long-term care facilities have an HAI and are transferred to a hospital, these patients can also transfer the microorganisms responsible for their infections. Because of this, it is important to follow strict infection control practices, starting with correct hand hygiene, in long-term care facilities and during home care, as well as throughout hospitals.

The report stated that 35% of patients received at least one antimicrobial agent. Why is this usage so high, and what are the dangers of overusing antibiotics in the clinical setting?

It is difficult to say whether antibiotic use is high or not. Patients in hospitals include those with severe community-acquired infections that required hospitalisation and treatment with antibiotics, or those that underwent surgical procedures and required antibiotics for perioperative surgical prophylaxis.

In addition, because of their primary diseases, and the medical and surgical interventions that may be needed for the treatment of these diseases, hospitalised patients are more at risk of contracting HAIs and, therefore, more likely to receive antibiotics than patients outside hospitals.

How can antibiotics be better targeted, thus reducing the risk of drug-resistant superbugs' such as MRSA?

Improving antibiotic use in hospitals could be addressed by:

• performing proper microbiological diagnostics as soon as possible based on samples taken before
  the start of antimicrobial treatment, which will allow streamlining and targeting of such treatment
• shortening the treatment of certain infections with antibiotics; for
  example, current evidence shows that shortening the treatment of pneumonia from 15 to eight days does not result in poorer outcomes
• making sure that the duration of perioperative antibiotic prophylaxis in surgical patients is in accordance with evidence-based guidelines, which, in most cases, recommend only one dose preoperatively - prolonged duration of unnecessary perioperative surgical prophylaxis is one of the main reasons for high antibiotic use in hospitals.

Furthermore, ECDC has identified three strategies to address antibiotic resistance:

1. Prudent use of antibiotics is the cornerstone of preventing the emergence and spread of antimicrobial-resistant microorganisms, since the spread of antimicrobial resistance reported across Europe has been directly linked with antibiotic use.
2. Implementation of good infection control practices - including hand hygiene, as well as the screening and isolation of infected and colonised patients in hospitals - is important to prevent the spread of resistant bacteria.
3. Promoting the development of new antibiotics with novel mechanisms of action is essential because resistance inevitably builds over time. Proposing innovative incentives for the development of effective antibiotics is one of the priorities of the EU-US Transatlantic Task Force on Antimicrobial Resistance.

Are there any other therapies that could be used?

There are few alternatives to treat HAIs and that is why antimicrobials are still the main treatment for these kind of infections. Some examples are:

• reducing the size of the inoculum of bacteria by surgical debridement of the wound, wound cleaning
  and disinfection; this is common practice for wound infections, but complements rather than replaces antimicrobial therapy
• using specific bacteriophages as last-line therapy to treat MRSA sufferers with skin and soft tissue infection
• using probiotics or faecal transplantation to treat patients with Clostridium difficile infection
• in rare cases, if the infection is not life-threatening, employing supportive treatment rather than antimicrobials;
  for example, using symptomatic treatments such as anti-inflammatory drugs and allowing the body to fight the infection via its immune system.

What kind of cost factors are involved in treating HAIs?

Treating HAIs represents an extra cost for hospitals, mainly because a hospital bed occupied by a patient with a HAI cannot be used to treat another patient without an HAI. In 2008, ECDC estimated the total cost of HAIs at approximately €7 billion a year, based on the excess length of stay of patients with an HAI only.

These costs aside, due to extended hospital stays, treatment of HAIs generally requires specific types of antimicrobials, which can sometimes be slightly more expensive than those used to treat other types of infections.

Prevention and control measures also have a cost. If the HAI is due to a multidrug-resistant microorganism, such as MRSA, `special interventions such as isolation of the infected patient, and screening plus isolation of other infected or colonised (positive, but not infected) patients is essential to prevent further spread of the microorganism.

Finally, hand hygiene is a standard measure for the prevention of HAIs and may add a small cost to patient care, but it is the most effective way to decrease patient-to-patient spread of microorganisms and acquisition of HAIs.

What are the risks of getting HAI treatments wrong?

HAIs often occur as a result of microorganisms that are resistant to multiple antimicrobials.

Treatment of these infections is necessarily based on an informed guess of the responsible microorganism and its antimicrobial susceptibility profile - that is, empiric treatment. Itis therefore difficult for a prescriber to always know if the antimicrobial given will effectively treat that specific responsible microorganism.

Patients that don't receive appropriate antimicrobial treatment (which is active against the responsible microorganism(s)) from the start or within the first few days of infection have a higher risk of poor outcome, including death.

What are your primary recommendations to hospitals? What steps can they take to reduce the spread of bacteria throughout their wards?

It is important that hospitals follow strict infection control practices. However, many different actions and interventions are necessary for the prevention of HAIs - not one single intervention will work by itself.

To decrease the rates of HAIs, it is imperative that hospitals have strong support and buy-in from the hospital administration/institutional leaders. This includes active participation in infection control committees, being informed of HAI rates, and the provision of financial support, responsibility and commitment.

What degree of geographic variability are we seeing? Are there any countries in particular that seem to be doing a good job at reducing the incidence of HAIs?

Direct comparison of HAI prevalence percentages between countries was not an objective of the report and such comparisons should not be made without taking into account the case-mix (different types) of patients included in each country, the confidence intervals for the HAI prevalence percentages, and validity of the data reported by each country. Therefore, we cannot really comment on geographic variability.

This was the first study of its kind - what kind of confidence should we place in its results? Are follow-up studies needed, and how can hospitals improve their skills in monitoring HAIs?

With this ECDC report, a major first step has been made towards increasing HAI surveillance skills and awareness among healthcare workers across Europe.

Nevertheless, the continued training of healthcare workers who perform such surveys, as well as additional validation studies of national point prevalence surveys, are still needed to harmonise the interpretation of case definitions and improve the comparability of HAI prevalence percentages between European countries.

ECDC will organise a second Europe-wide survey across all EU member states in 2016-17, and will continue supporting the organisation, data collection, validation and analysis of national surveys during the period 2013-15.