No 42/43 - 2020

DANMAP 2019

This year’s DANMAP report describes the results from the national monitoring of antimicrobial resistance and antimicrobial consumption in humans, animals and foods in Denmark. The DANMAP cooperation has been in place since 1995 and annual reports have been published since 1997.

The full report as well as reports from previous years are available at the DANMAP website.

The total consumption of antimicrobials for animals as well as humans is low in Denmark compared with the EU and the rest of the world. With regard to human consumption, consumption is primarily low in primary healthcare. The corresponding total occurrence of antimicrobial-resistant isolates from infections is also low in Denmark, and - for most bacterial species - no major increases in the share with resistance have been observed. Even so, the total number of treatment-requiring infections follows an increasing trend, and more patients have an invasive infection with resistant bacteria than previously. This seems to drive the antimicrobial consumption at hospitals - where consumption is relatively high, even in a European context. Therefore, it remains important to focus on reducing antimicrobial consumption where this is deemed possible, and to use narrow-spectrum antimicrobials whenever possible.

The Danish National Action Plan for Antimicrobials for Humans published in 2017 aims to reduce the number of antimicrobial prescriptions, to increase the use of narrow-spectrum rather than broad-spectrum antimicrobials and to reduce consumption of the critically important antimicrobials in hospitals. Since 2012, primary healthcare has observed a sustained decrease in the number of redeemed prescriptions among GPs, medical specialists and dentists alike. Since the introduction of the action plan, this trend has become even clearer, producing a considerable reduction that is evident in all Danish municipalities and regions. At hospitals, total consumption has increased but an expedient change has been observed in the pattern of consumption. Particulary, the use of the critically important antimicrobials (cephalosporins, fluoroquinolones and carbapenems) has changed and their share of total antimicrobial consumption now follows a decreasing trend.

Below, we describe the main findings for 2019.

Antimicrobial consumption in animals

In 2019, the total consumption of antimicrobials for animals was approx. 97 tonnes. This is the lowest level recorded since 2002 and corresponds to a 24% decrease since 2010.

Antimicrobial consumption in humans

In 2019, the overall human antimicrobial consumption was 15.76 defined daily doses per 1,000 inhabitants per day (DID), which is lower than the 2018 consumption (15.97 DID) and also lower than the consumption recorded ten years ago (18.31 DID). In Denmark, primary healthcare is responsible for approx. 90% of the antimicrobial consumption, whereas the remaining 10% are used in hospitals. In primary healthcare, consumption peaked in 2011 after which it has shown a declining trend, whereas hospital consumption follows an increasing trend. In 2018, penicillines continued being the most consumed antimicrobial group in primary healthcare (65%) and also at hospitals (54%).

In 2019, the three critically important groups of antimicrobials (fluoroquinolones, cephalosporins and carbapenems) comprised 18% of consumption of antimicrobials at hospitals, measured as defined daily doses (DDD) per 100 bed days, which is a decline from 20% recorded for 2018 and 31% recorded for 2010.

Resistance in clinical bacteria in humans

Over the past ten years, the number of invasive infections (blood poisonings) in humans, monitored by DANMAP, has increased considerably; a trend that continued in 2019 for several bacterial species.

Escherichia coli is the bacterium most frequently found in blood poisonings. From 2010 to 2019, the number of blood cultures with E. coli findings increased by 64%, from 3,418 to 5,613 annual cases. In the same period, the share of E. coli with resistance to cefuroxime increased from 8.4% resistance in 2010 to 10.2% in 2019.

For Staphylococcus aureus, Klebsiella pneumoniae and Enterococcus faecium, the number of blood poisonings has also risen over the past ten years. The share of methicillin-resistant S. aureus in blood cultures has increased by a mean 4% since 2005, but, even so, it remains among the lowest in Europe; and in 2019, 2.1% was recorded. Generally, a decrease has been observed in the share of resistant K. pneumoniae compared with ten years ago, but this decrease primarily occurred in the 2010-2015 period. The share of E. faecium from blood cultures with resistance to vancomycin (VRE) has increased considerably from 1.8% (nine patients) in 2010 to 11% (79 patients) in 2019. However, from 2018 to 2019, the share has not increased and therefore 2018 with 12% VRE (97 patients) currently features the highest resistance share observed in Denmark in E. faecium from blood cultures. In contrast, 2019 observed a continued increase in the number of patients with VRE findings elsewhere than in the blood.

The reference laboratory at the SSI receives isolates of Gram-negative bacteria on suspicion of carbapenem resistance (carbapenemase-producing organisms, CPO), both from rectal screenings and clinical samples for further investigation of possible resistance genes. In 2019, the number of verified CPOs increased to a total of 221 cases in 187 patients, a 25% increase compared with the previous year. In addition to verifying resistance genes, whole-genome sequencing of CPO isolates allows for comparison of the DNA profiles of the bacteria to identify and contain CPO outbreaks. 2019 witnessed a total of 16 CPO outbreaks with new patients. The majority of the outbreaks spanned several years. Three major, prolonged outbreaks involved 19, 39 and 41 patients, respectively, but the majority of outbreaks were limited in size (2-9 patients).

Resistance in zoonotic bacteria, i.e., bacteria that transmit (directly or indirectly) from animals to humans

Like in the preceding years, 2019 recorded a higher level of resistance in Campylobacter jejuni in patients who had recently been travelling abroad compared with infections acquired in Denmark.

Macrolide (erythromycin)-resistant C. jejuni were observed in 4% of patients with a known travel history, whereas no macrolide resistance in C. jejuni was isolated from patients who had acquired the infection in Denmark. In contrast, fluoroquinolone resistance was observed frequently in travel-related cases and in cases acquired in Denmark, and 70% of all C. jejuni isolates were resistant to ciprofloxacin.

With respect to Salmonella, the DANMAP monitoring efforts are focused specifically on S. Typhimurium, and for this serotype approx. two thirds of the human infections are caused by a closely related clone that is resistant to ampicillin, sulfonamide and tetracycline. Among Salmonella, resistance to critical antimicrobials, i.e., third-generation cephalosporins, carbapenems, gentamicin and colistin, is only rarely observed (< 1% for cephalosporin and carbapenem-resistance in S. Typhimurium in 2019). Resistance to fluoroquinolones remained at a high level in 2019 for isolates from travel-associated cases (14%) compared with 4% among isolates from infections acquired in Denmark. Less than 1% of S. Typhimurium-isolates were resistant to azithromycin.

(S. Skovgaard, M. Attauabi and J. Boel, Department of Bacteria, Parasites and Fungi)