No 47 - 2010

DANMAP 2009: Antimicrobial consumption and resistance

The annual DANMAP report (Danish Integrated Antimicrobial Resistance Monitoring and Research Programme) records the Danish consumption of antimicrobial agents used for animals and humans and follows the development of resistance in bacteria collected from animals, food and humans.

The 2009 DANMAP report is available at www.danmap.org.
The report describes the main characteristics of and trends in antimicrobial consumption and resistance in humans.

Antibiotics consumption in primary health care

In 2009 the total consumption of antibiotics in primary healthcare comprised 15.95 defined daily doses (DDD) per 1,000 inhabitant days versus 15.91 in 2008. The increasing trend, which started in 2000, consequently seems to have levelled off.

However, the consumption of broad-spectrum antibiotics (combinations of penicillins/beta-lactamase inhibitors and tetracyclines) continues to increase, while the consumption of narrow-spectrum antibiotics (beta-lactamase sensitive penicillin and macrolides) decreases. Beta-lactamase sensitive penicillins remain the most frequently used drug (32 % of total consumption) followed by extended spectrum penicillin (21 %) and macrolides (14 %).

Antibiotics consumption at hospitals

In 2009 the total hospital consumption expressed as DDD per 100 bed-days (DBD) increased by 4.8 % (from 74.56 in 2008 to 78.13 in 2009).
With the exception of beta-lactamase sensitive penicillins, aminoglycosides and imidazol derivatives, the consumption of all important drug groups increased.

Cephalosporins comprised 21 % of the total hospital sector consumption, followed by extended spectrum penicillins (18 %), fluoroquinolones (13 %) and beta-lactamase sensitive penicillins.

The carbapenem consumption, which in 2001 comprised less than 1 % of the total consumption, had risen to 4 % by 2009 (from 0.39 DBD in 2000 to 2.94 DBD in 2009). Thus, this consumption has increased more than seven fold since 2000.

Over the past decade (2000-2009), the total antibiotic consumption in hospitals has increased by 31.2 DDD per 100 bed-days, equivalent to a 66 % increase.
In the same period, the hospital-based consumption of broad-spec¬trum antibiotics increased by 125 %.

Resistance

For Escherichia coli and Klebsiella pneumoniae from blood and urinary tract infections, a significant increase in resistance to most antibiotics was seen compared with 2008, Table 1.

The proportion of multi-resistant K. pneumoniae isolates (3rd generation cephalosporins, quinolones and gentamicin) rose from 1 % in 2006 to 8 % in 2009. No E. coli and K. pneu-moniae isolates from blood infections were carbapenem-resistant.

The ESBL prevalence study performed in October 2009 recorded an increase in the occurrence of ESBL-producing K. pneumoniae and E. coli in Danish patients, EPI-NEWS 15/10.

In 2009 the occurrence of penicillin and erythromycin resistance remained low among Streptococcus pneumoniae, and group A, B, C and G streptococci. For S. pneumoniae, erythromycin resistance fell from 6.6 % in 2008 to 3.6 % in 2009.

From 2002 to 2009, the number of Enterococcus faecium blood infections rose from 137 to 413 (201 %). Among these, the ampicillin resistance was high (87 %) in 2009. The occurrence of vancomycin resistance was 1.6 % in E. faecium isolates and less than 1 % in E. faecalis blood isolates.

The number of methicillin-resistant S. aureus (MRSA) among patients with S. aureus bacteraemia was 23 (1.6 %). This is a very low proportion compared with the rest of Europe.

In 2009 the number of new MRSA cases was at par with that of 2008, EPI-NEWS 18/10. At the time of diagnosis a total of 60 % had a symptom-producing infection. The majority of cases were community-acquired and the number of hospital-acquired cases remained unchanged.

A total of 39 new cases of MRSA CC398 were detected, primarily in persons with close contact to live pigs. There were no signs of major spreading of this particular animal-related type of MRSA to the public.

Commentary

Denmark currently sees the consequence of the increasing consumption of broad-spectrum antibiotics (particularly at hospitals).

The increase in the occurrence of resistant K. pneumoniae and E. coli isolates has taken place concurrently with an increase in the consumption of several broad-spectrum antibiotics (ciprofloxacin, 2nd and 3rd generation cephalosporins and carbapenems) and is now at par with the levels seen in several Central and South European countries.

Another consequence of the increased consumption is a rise in the number of Clostridium difficile 027 infections, EPI-NEWS 18/10.

Previous treatment with fluoroquinolones, cephalosporins or carbapenems has been described as risk factors for the development of E. faecium infections, which, as mentioned above, have also increased markedly.

Denmark's position characterised by a low antibiotics consumption and a low occurrence of resistance has changed.
It is necessary to increase efforts to ensure an expedient use of antibiotics and to avoid any unnecessary use, particularly at hospitals.
(A.M. Hammerum, U.S. Jensen, L. Skjøt-Rasmussen, S.S. Olsen, L. M. Lambertsen, C.H. Lester, A. Petersen, R.L. Skov, N. Frimodt-Møller, Department for Microbiological Monitoring and Research)

Individually notifiable diseases and selected laboratory diagnosed infections (pdf) 

24 November 2010