Superbugs spreading into the community
Antibiotics prescribed by family doctors are increasingly failing to eliminate infections in a worrying sign that the problem of antibiotic resistance is spreading well beyond hospitals.
A large British study has found that more than one in every 10 antibiotics prescribed in the primary care setting are failing, and that the failure rate has increased in the past 20 years.
The research, involving data gleaned from 14 million patients who received 11 million antibiotic prescriptions between 1991 and 2012, found that pneumonia, bronchitis and other lower respiratory tract infections were becoming the most intractable to treat – the failure rates for antibiotics prescribed for these infections jumped 35 per cent in the period covered by the study.
The Cardiff University study adds to evidence that the effectiveness of antibiotics is waning.
The World Health Organisation has warned that rising antimicrobial resistance threatened the effective prevention and treatment of an ever-increasing range of infections, and posed an “increasingly serious threat to global public health”.
In Australia, highly drug resistant infections such as methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Gram-negative bacteria are becoming increasingly common in hospitals, and cases of multidrug- and cephalosporin-resistant gonorrhoea have emerged.
In a report prepared for the Federal Health Department, a team of Adelaide University researchers led by Professor John Turnidge confirmed the prevalence of antibiotic-resistant strains of disease-causing bacteria such as E.coli was steadily rising.
“The research has shown that we're having steadily increasing resistance now, to the point where we're seeing more than 5 per cent of strains being resistant to multiple antibiotics,” Professor Turnidge told the ABC. “Previously people think of the resistance as being in hospital. We now know it's very much a community problem as well.”
The Adelaide University team found general community resistance to three types of antibiotics in more than 7 per cent of E.coli samples taken from 29 health centres, compared with 4.5 per cent four years earlier.
Professor Turnidge said a culture of entitlement around the prescription of antibiotics was fuelling the problem – a point underlined by the Cardiff University study.
“There is a strong link between the rise in antibiotic treatment failure and an increase in prescriptions,” Cadiff University School of Medicine researcher Professor Craig Currie said. “Between 2000 and 2012 the proportion of infections being treated with antibiotics rose from 60 to 65 per cent, which is the period in which we see the biggest increase in antibiotic failure rates.”
Professor Currie said failure was most marked where the antibiotic prescribed was not considered a first-choice treatment for infection involved.
“We need to ensure that patients receive the appropriate medication for their condition, and minimise any unnecessary or inappropriate treatment which could be fuelling microbial resistance to antibiotics, prolonging illness and, in some cases, killing people,” he said.
For the Cardiff University study, an antibiotic treatment was considered to have failed if, within 30 days, a different drug was prescribed, a patient was hospitalised because of an infection-related diagnosis, a patient was referred to in infection-related specialist, of a patient died with an infection-related diagnosis.
Professor Currie said his research emphasised that superbugs were not just a problem in hospitals, but also in the broader community.
“There is a mistaken perception that antibiotic resistance is only a danger for hospitalised patients, but recent antibiotic use in primary care is the single most important risk factor for an infection with a resistant organism,” he said. “Furthermore, what happens in primary care impacts on hospital care, and vice versa.”
The study was funded by Abbott Healthcare Products and has been published in the British Medical Journal.
Published: 30 Sep 2014