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Swedres-Svarm Summary 2020

The situation in Sweden regarding antibiotic resistance in bacteria in humans and animals is still favourable from an international perspective. This confirms that our strategies to promote the rational use of antibiotics and to limit the spread of antibiotic resistance are effective

This is also seen in most Swedish reports of noti­fiable infectious diseases in humans. In contrast, the resist­ance levels among clinical isolates from humans in general have followed previous trends and do not seem to have been especially affected by the pandemic. The extensive impact of the COVID-19 pandemic on society and health care has also affected the sampling for resistant bacteria, the number of hospital admissions, the number of visits as well as the type of visits to health care facilities in general.

The situation in Sweden regarding antibiotic resistance in bacteria from humans has been, and still is, favourable from an international perspective. One contributing factor is that our strategies to promote the responsible use of antibiotics and to limit the spread of antibiotic resistance are effective. Despite our relatively good situation, there are problems with cross infection and increasing antibiotic resistance, which calls for continued efforts in preventive work. Important examples are the recurrent outbreaks of vancomycin-resistant enterococci in hospitals, and an increasing number of health care related clusters of ESBLCARBA.

The reduction of antibiotic sales for humans continued in 2020, after several years of decreasing trends. Compliance with treatment recommendations is increasing, thus decreasing the use of broad-spectrum antibiotics.

In veterinary medicine, sales of antibiotics have decreased markedly since the mid 80s. During the last years, sales seem to have stabilised at a comparatively low level. The occurrence of resistance among bacteria from animals has generally been stable at low or moderate levels. For some substances and in some bacteria the occurrence of resis­tance is even declining. One example of this is the occurrence of ESBL producing Escherichia coli among broilers that has declined significantly. There are however exceptions, and for example resistance to ampicillin, sulphonamides, and trimethoprim has increased in indicator E. coli from both broilers and pigs.

Key findings 2020

  • The total sales of antibiotics for humans in Sweden decreased by 13% in 2020 compared to 2019, as measured in DDD per 1 000 inhabitants per day.
  • Overall, there are substantial reductions in sales of antibiotics in all care sectors between 2019 and 2020, which can be put in relation to the COVID-19 pandemic.
  • The national average for antibiotic prescriptions to humans has decreased further and in 2020 the long-term target of 250 prescriptions per 1 000 inhabitants per year was reached nationally.
  • The proportion of MRSA among Staphylococcus aureus isolated from blood has increased to 2.3%, compared to 1.8% 2019.
  • There was an increasing number of health care-related, smaller clusters of ESBLCARBA, from one in 2019 to three in 2020.
  • In relation to the pandemic, all mandatory reported antibiotic resistance, except pneumococci with decreased susceptibility to penicillin, has decreased. This is not seen for resistance levels among clinical isolates, where trends are relatively unaffected.
  • Sales of antibiotics for animals are stable at a low level and are dominated by narrow-spectrum penicillin.
  • MRSA is uncommon among both farm and companion animals.
  • The decreased occurrence of ESBL-producing coli in samples from broilers that has been seen in the latest years was stabilised in 2020.
  • ESBLCARBA-producing bacteria have not been confirmed in animals in Sweden.

Sales of antibiotics

Sales of antibiotics for humans

The total sales of antibiotics for humans in Sweden were 13% lower in 2020 and are now 9.7 DDD per 1 000 inhabitants per day. This figure encompasses all antibiotics sold on prescription to individuals and all antibiotics sold to hospitals and other health care facilities. The sales of antibiotics in 2020 were largely affected by the COVID-19 pandemic and a decrease in sales was seen in all health care sectors, especially in outpatient care.

Outpatient care

The sales of prescriptions dispensed at pharmacies in Sweden decreased by 17% in 2020. The sales decreased in all age groups compared to 2019, but the decrease was most noticeable among children. The most substantial decrease was seen among antibiotics commonly used to treat respiratory tract infections (28%). The national average number of sales in prescriptions per 1 000 inhabitants per year was 237 in 2020, which means that the national long-term target of 250 prescriptions per 1 000 inhabitants per year was reached nationally and in 19 out of 21 regions in 2020.

The sales of antibiotics in dentistry continued to decrease in 2020 by an additional 3.2%, compared with 2019. Since 2007, the sales in dentistry have been reduced by half.

A tendency for increased sales of antibiotics prescribed by digital care providers was seen in 2020.

Hospitals and other health and social care facilities

In 2020, the sales of antibiotics on requisition decreased to 1.36 DDD per 1 000 inhabitants per day, a decrease of 4.1% compared with 2019. This includes all antibiotics sold to hospitals, other healthcare facilities and some nursing homes. The sales to acute care hospitals decreased compared to 2019, as measured in DDD per 100 admissions, but remained at the same level as in 2019 as measured in DDD per 100 patient-days.

The sales of antibiotics in hospital care in total and to acute care hospitals decreased, especially among beta-lacta­mase sensitive and resistant penicillins (J01CE and J01CF). Despite the decrease, these classes are still among the most sold. The sales of cephalosporins and combinations of penicillins to acute care hospitals have continued to increase. The use of broad-spectrum antibiotics – cephalosporins, carbapenems, fluoroquinolones and piperacillin-tazobactam – shows large regional variations in terms of which substances are used. The relative use of penicillins measured in DDD also varies between the regions.

Sales of antibiotics for animals

Data for procaine benzylpenicillins from 1980 to 2019 have been recalculated following a change in a factor used for the calculation of active substance. As a result, the figures are generally somewhat lower than what have been published in previous years.

In 2020, reported sales of antibiotics for animals were 9 306 kg, of which 54% were penicillins with narrow spectrum. The corresponding figures for 2011 were 12 220 kg and 52%, respectively.

Since the withdrawal of growth-promoting antibiotics from the Swedish market in 1986, the total sales of antibiotics have decreased by more than two thirds when corrected for population sizes over time. During the 1990s, sales of veterinary products for medication of groups of animals decreased, and in the past decade there has also been a decrease in sales of products for use in individual animals.

Comparing sales of antibiotics in human and veterinary medicine

In 2020, a total of 54.0 tonnes of antibiotics were sold for human use and 9.1 tonnes were sold for animal use (excluding products for intramammary or intrauterine use). Measured as milligrams of active substance per kilogram biomass, the sales were 79.8 and 11.9 milligrams per kilogram, respectively. Antibiotic sales for humans still dominate for all included classes of antibiotics except for aminoglycosides.

Notifiable resistance

ESBL-producing Enterobacterales (previously Enterobacteriaceae)

ESBL-producing Enterobacterales (previously Enterobacteriaceae) in humans has been subject to mandatory notification since 2007. It is the most common one of the antibiotic resistance types for which notification is required.

Results 2020, Enterobacterales (previously Enterobacteriaceae) with ESBL

  • Number of reported cases: 8 230 (previous year 10 717), relative change –23%.
  • Number of bloodstream infections: 727 (previous year 835), relative change –13%.
  • As in previous years, Escherichia coli was the most common species, (87%), followed by Klebsiella pneumoniae, (9%).

Results 2020, Enterobacteriaceae with ESBLCARBA

  • Number of reported cases: 128 (previous year 201), relative change –36%.
  • Number of bloodstream infections: 11 (previous year 6).
  • The number of health care related, clusters of ESBLCARBA increased, from one in 2019 to three in 2020.
  • Among Enterobacterales (previously Enterobacteriaceae) with ESBLCARBA, coli was the most common species, (61%) followed by Klebsiella pneumoniae (26%).

ESBL-producing Enterobacterales (previously Enterobacteriaceae) are rare among animals in Sweden. Previously, the occurrence in intestinal samples from broilers was high but it has decreased in recent years. In 2020, the occurrence of ESBL-producing E.coli in intestinal samples from broilers and turkeys, as well as samples of broiler meat was investigated with screening methods. Such bacteria were isolated from 3% and 0% of the intestinal samples from broilers and turkeys respectively, and 2% of the broiler meat samples of Swedish origin.

ESBLCARBA-producing bacteria were not confirmed in animals in Sweden.

Methicillin-resistant Staphylococcus aureus (MRSA)

Community-acquired infection has long been the most common type in humans, with two-thirds of the cases. In 2015, community-acquired infection was divided into family/ household-related infection and community-acquired infection. Family/household-related infections and community-acquired infections both accounted for 32% of the cases.

Results 2020

  • Number of reported cases: 3 112 (previous year 3 858), relative change -19%.
  • Number of bloodstream infections: 98 (previous year 72), relative change +36%.
  • The proportion of MRSA among Staphylococcus aureus isolated from blood has increased to 2.3% in 2020, compared to 1.8% in 2019.

The occurrence of MRSA in animals in Sweden is still low, which limits the spread from animals to humans. MRSA was found sporadically in horse, dog and cat. However, the number of MRSA cases in horses was tripled in 2020, compared to the previous highest figure of nine cases in 2014. The increase could be explained by outbreaks in two equine hospitals with a total of 18 cases. In companion animals, the same types of MRSA as in humans dominate, indicating a human source of MRSA in these animals. In horses, livestock-associated MRSA clonal complex 398 used to be the most common, but in 2020 spa-type t1971 dominated (14 of 27 cases). This vari­ant is since 2019 a new finding in horses in Sweden.

Methicillin-resistant Staphylococcus pseudintermedius (MRSP)

In 2020, the number of reported cases of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in animals was around the same level as in previous years. In total 49 cases of MRSP were notified to the Swedish Board of Agriculture, and isolates from 47 cases from dogs were available for further investigations. The epidemiology of MRSP is more diverse compared to earlier years with several sequence types occurring.

MRSP in humans is not notifiable.

Streptococcus pneumoniae with reduced susceptibility to penicillin (PNSP)

Results 2020

  • Number of reported cases: 112 (previous year 118), relative change –5%.
  • Number of bloodstream infections: 4 (previous year 9).

Vancomycin-resistant enterococci (VRE)

Results 2020

  • Total number of reported cases: 79 (previous year 232), relative change –66%.
  • Number of reported cases of faecium with vancomycin resistance: 77 (previous year 221), relative change –65%.
  • Number of reported cases of faecalis with vancomycin resistance: 4 (previous year 11).
  • There were two cases infected with both faecium and E. faecalis.
  • Number of bloodstream infections: 4 (previous year 10).
  • Eight hospital-related outbreaks were reported during the year with 2-7 cases each. In 2019, 22 hospital-related outbreaks were reported.

In 2020, the occurrence of VRE in intestinal samples from broilers was investigated with screening methods. Such bacteria were isolated from 6% of the samples. This shows that the decrease in occurrence of VRE among broilers in Sweden since 2005 has continued. All of the isolates belonged to the clone of E. faecium with vanA that is the most common among VRE in broilers in Sweden.

Zoonotic pathogens

Salmonella is rare in animals in Sweden. Furthermore, only a few of the incidents involve antibiotic-resistant strains. Resistance to fluoroquinolones is rare. For Salmonella species isolated from human faeces, the highest occurrence of resistance was against fluoroquinolones, (20%). No resistance to meropenem was reported. Isolates from human invasive infections with Salmonella are markedly more resistant, probably due to the large proportion of cases acquired abroad.

Campylobacter from animals in Sweden are generally susceptible to relevant antibiotics, and resistance to erythromycin, for example, is most uncommon. In Campylobacter jejuni from humans, resistance to ciprofloxacin was 43% and resistance to tetracycline was 24% in 2020. One percent were resistant to erythromycin.

Infections, either in humans or in animals, caused by Salmonella and Campylobacter are usually not treated with antibiotics. In humans, only a small proportion of the isolates are tested for antibiotic susceptibility, most of which are related to serious infections. See the “Comparative analysis” section of each bacterium.

Human clinical isolates

All data for these compilations are collected automatically via Svebar, a collaboration between the clinical microbiological laboratories and the Public Health Agency.

  • Escherichia coli: Resistance in blood isolates to ceftazidime and cefotaxime was 6-8%. The number of reported coli ESBL from blood was 601 cases in 2020. Resistance to ciprofloxacin is now 14% and 11%, respectively, in isolates from blood and urine. This needs to be noted when choos­ing empirical treatment for febrile urinary tract infection.
  • When coli from urine are age and gender distributed, some differences in resistance are seen. Most prominent is the high ciprofloxacin resistance (16-20%) seen among men 20 years and older.
  • Klebsiella pneumoniae: resistance in blood isolates to cefo­taxime and ceftazidime was 6-7%. The number of reported pneumoniae ESBL from blood was 104 in 2020. As for E. coli, resistance to ciprofloxacin is now relatively high, 8-10% in isolates from urine and blood.
  • Staphylococcus aureus: Resistance to cefoxitin (which is indicative of MRSA) in isolates from blood and samples from skin and soft tissue was 2.3% and 2.2% respectively. The number of reported MRSA from blood was 98 in 2020.
  • Enterococcus faecalis and Enterococcus faecium: Vancomycin resistance in isolates from blood remains low (0% and 0.3%, respectively) and the high-lewel aminoglycoside resistance has decreased.
  • Clostridioides difficile: The incidence has decreased by 9% from 2016 to 2020 (60 cases per 100 000 inhabitants). No isolates were tested for antibiotic resistance.

Animal clinical isolates

Bacteria causing clinical disease in animals are mostly susceptible to antibiotics relevant for treatment. Respiratory pathogens from farm animals and horses are generally susceptible to bensylpenicillin, but penicillin resistance is common in Staphylococcus pseudintermedius from dogs and occurs in S.aureus from horses and S.felis from cats. Resistance in E.coli occurs in all animals but is most prominent in enteric isolates from young calves and pigs. Susceptibility testing for guidance in antibiotic therapy is warranted, especially for staphylococci, E.coli, and Brachyspira spp.

Indicator bacteria from healthy animals

Antibiotic resistance in E. coli from the intestinal flora of healthy animals serves as an indicator for the presence of resistance in an animal population. The prevalence of acquired resistance in such commensal bacteria also indirectly indicates the magnitude of the selective pressure from the use of antibiotics in an animal population. The prevalence of resistance in indicator bacteria from animals in Sweden is low, and the situation is favourable in an international perspective.

Last updated : 2021-08-25