A new surveillance report from Public Health England (PHE) shows a mixed picture in the battle against antimicrobial resistance (AMR), with little change in the proportion of antibiotic-resistant isolates detected in the country's healthcare system over the past 5 years but an upward trend in the number of resistant bloodstream infections.
The fourth annual report from the English Surveillance Program for Antibiotic Utilisation and Resistance (ESPAUR), which includes data from 2012 through 2016, also shows a 5% overall reduction in antibiotic consumption, driven largely by less antibiotic use in the primary care setting.
The report was released on the same day that PHE launched its Keep Antibiotics Working campaign. The campaign, which is aimed at the general public, warns that antibiotics aren't needed for minor ailments like coughs, earaches, and sore throats, and that taking unnecessary antibiotics can encourage antibiotic resistance. PHE estimates that up to a fifth of antibiotic prescriptions written in England are unnecessary, and that as many 5,000 people die each year from drug-resistant infections.
The English government has set a goal of cutting the number of gram-negative bloodstream infections and inappropriate antibiotic prescriptions in half by 2021.
Resistance trends in gram-negative bacteria
The ESPAUR report focuses on trends in resistance among gram-negative bacteria that cause bloodstream infections, with Escherichia coli being the most frequent cause. The data showed that in 2016, 40.8% of E coli bloodstream isolates were resistant to co-amoxiclav, the most common antibiotic used to treat hospital infections, and 1 in 5 isolates were resistant to at least one other key antibiotic.
Over the 5-year period, the proportion of E coli bloodstream isolates resistant to co-amoxiclav (37.3% to 40.8%), ciprofloxacin (18.1% to 18.7%), third-generation cephalosporins (10.8% to 12.4%), gentamicin (9.3% to 10.1%), and piperacillin-tazobactam (9.6% to 11.8%) increased but remained relatively stable overall. The proportion of E coli bloodstream isolates showing multidrug-resistance (to at least 3 drugs) was also stable, ranging from 3% to 5%.
But the data also showed that the incidence of E coli bacteremia increased by 24.3% over the 5-year period, climbing from 32,405 cases in 2012 to 40,272 cases in 2016, an indication that the burden of resistance in the English healthcare system continues to grow.
The same trend was observed with Klebsiella pneumoniae and Pseudomonas aeruginosa, two other gram-negative pathogens that cause bloodstream infections. While the proportion of K pneumoniae and P aeruginosa bloodstream isolates resistant to key antibiotics also remained relatively stable from 2012 through 2016, the number of bloodstream infections caused by these pathogens rose from year to year. And the numbers could be even higher, since reporting of bacteremia caused by K pneumoniae and P aeruginosa is voluntary (reporting of E coli bacteremia is mandatory).
"This serves to highlight the importance of infection prevention and control as a key intervention for tackling AMR," the authors of the report write.
The report also found that drug resistance was common in the more than 1 million urinary tract infections (UTIs) in 2016, with low levels of resistance to the first-line therapy nitrofurantoin (2.7% in community settings and 3.2% in acute care settings) and much higher levels of resistance to trimethoprim (34% and 37%, respectively). Resistance to ciprofloxacin, which is used to treat complicated UTIs, was seen in 12% and 15% of urine isolates in community settings and acute care settings, respectively.
Another concerning finding was that while resistance to carbapenems in bloodstream isolates of E coli and K pneumoniae remained low, the detection of carbapenemase-producing Enterobacteriaceae (CPE) isolates continues to increase year to year. CPE are frequently resistant to multiple classes of antibiotics. As a result, the authors say that surveillance for CPE and other multidrug-resistant strains of bacteria is being expanded.
Declining antibiotic consumption
The data on antibiotic consumption, meanwhile, suggest that efforts by England's National Health Service (NHS) to reduce antibiotic prescribing are having an impact, particularly in primary care.
According to the report, antibiotic consumption in England declined by 5.1% in primary and secondary care settings from 2012 through 2016, falling from 22.6 to 21.4 defined daily doses (DDD) per 1,000 inhabitants per day. Over this period, decreasing consumption was observed across most major classes of antibiotics—penicillins (-7.4%), cephalosporins (-28.6%), quinolones (-5.8%), macrolides (-6.6%), and sulfonamides and trimethoprim (-12.3%).
The decline in consumption was driven mainly by reduced prescribing in the primary care setting, where nearly 75% of antibiotics are prescribed. The data show that consumption in primary care decreased from 17.3 to 15.9 DDD per 1,000 inhabitants per day over the 5-year period, a decline of 8.1%. This figure included an 11.5% decline in prescribing by dentists. Other settings within the primary care designation, including after-hours and walk-in clinics and urgent care, saw an increase in prescribing.
Antibiotic consumption also climbed in secondary care settings, rising from 3.58 to 3.81 DDD per 1,000 inhabitants per day from 2012 through 2016, a 6.5% increase. The authors say this increase, which occurred mainly among hospital inpatients, reflects increased hospital activity. Notably, the 5-year period saw rising consumption of ultra-broad-spectrum antibiotics like piperacillin/tazobactam, carbapenems, and colistin. Increasing use of these drugs is a particular concern in English hospitals because they represent the last line of defense against serious, multidrug-resistant infections.
Oct 23 ESPAUR Report 2017
Oct 23 PHE Keep Antibiotics Working campaign