Dossier n. 225/2012 [Abstract] Surveillance of antimicrobial resistance and consumption of systemic antibiotics in Emilia-Romagna. Report 2010

The regional antimicrobial resistance surveillance system of Emilia-Romagna, providing data since 2003, has shown a progressive increase of antimicrobial resistance rates in most bacterial species relevant to human health, especially among Gram-negatives bacteria. Over the years there has been a very worrying growth of infections caused by microorganisms producing extended-spectrum beta-lactamase (ESBL), increasingly common not only among hospitalised patients with high complexity of care (e.g. patients in intensive care) but also in patients in other hospital units and in the community. Invasive infections by ESBL-producing bacteria are, in most cases, treated with carbapenems (imipenem, meropenem and ertapenem); hence, the use of this antibiotics has significantly increased over time.

The situation has shown a further quantum leap in the second half of 2010 for the spread of strains of carbapenemase-producing K. pneumoniae that are resistant to almost all antibiotics available and, therefore, are very difficult to treat. This trend is also seen in other areas in Italy as witnessed by the European surveillance system (EARS-Net 2010). For this reason, the Agenzia sanitaria e sociale regionale (ASSR) of Emilia-Romagna has prepared a guideline document for the diagnosis, surveillance and control of the carbapenemase-producing Enterobacteriaceae in hospital (Gagliotti et al., 2011) followed by two insights for the management of patients colonized or infected by these organisms in rehabilitation units (Gagliotti et al., 2012), in long term health-care facilities and in the community (Ragni et al., 2011). The enhanced surveillance activities to monitor the progress of cases in the region, implemented through the regional guideline, include a monthly summary report that is produced by each Local Health Authority (LHA) and uploaded in the Regional SharePoint web site of Infection Control Committees. Data from this new surveillance system are available starting from June 2011 and are fed back to the LHAs through a monthly report including the overall regional trend and specific trends of each hospital.

Besides the increase in the antimicrobial resistance rate, there was a significant growth in the overall frequency of invasive bacterial infections. The incidence rates of bacteraemia passed, in the period 2005-2010, from 146 to 223 episodes per 100,000 inhabitants/year (+53%). Rates of bacteraemia caused by Escherichia coli and Klebsiella pneumoniae showed a more manifest increase (+95% and +146% respectively) associated with a greater increase in antibiotic resistance, compared to those caused by other bacterial species.

Pseudomonas aeruginosa and Acinetobacter baumannii are other relevant species among Gram-negative bacteria with a high prevalence of antibiotic resistance. The latter was also characterized (in 2009) by a dramatic increase in the rates of bacteremia and of other infections caused by isolates resistant to carbapenems.

Trends of resistance and infection rates of Gram-positive microorganisms such as Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium and Streptococcus pneumoniae, appeared more stable than those of Gram-negatives.

The use of systemic antibiotics, evaluated by regional databases, showed significant increases in all health care settings until 2009 while in 2010 the upward trend was limited to hospitals (90.3 DDDs/100 bed-days) and a decrease was observed in the community (18.9 DDDs/1,000 inhabitants-day). The reduction in use of antibiotics observed in 2010 at community level, mainly concerns the age group between 7 and 19 years (-16% compared to 2009) and, to a lesser extent, younger children and young adults while, in the age groups ≥60 years, the figure is essentially unchanged from the previous year. The antibiotics most used both in hospital and in community settings are the penicillins associated with beta-lactamase inhibitors. In hospital, the fluoroquinolones are the second most widely used class of antibiotics and carbapenems are the antibiotics with the biggest relative increase of prescriptions (96% vs. 28% average increase). The macrolides are the most used antibiotics, after the penicillins associated with beta-lactamase inhibitors, in the community.

The overall picture of antimicrobial resistance in Emilia-Romagna, already worrying for the size of the problem and its increasing trend, is significantly worsened by the spread of carbapenemase-producing Enterobacteriaceae. The appropriateness of use of antibiotics and the infection control measures (including hand hygiene) are therefore, now more than ever, a priority in all health care settings of Emilia-Romagna.