An interview with Dr Norman Moore, conducted by James Ives (MPsych)
As we enter colder months the rate of illnesses is set to rise. Without testing for specific viruses or pathogens how do doctors know what to prescribe patients? What is typically the diagnostic gold standard approach?
During the winter months, patients frequently present with respiratory symptoms like coughing, sneezing and fever that could be caused by one of several bacterial and viral infections including influenza, respiratory syncytial virus (RSV) or bacterial pneumonia.
In many cases, these patients are treated empirically, meaning that doctors will treat based on previous experience, because until recently accurate screening was not possible within an actionable timeframe, i.e., during a patient’s visit.
While in many cases, a healthcare provider’s (HCP) assessment of symptoms is correct, studies have shown that evaluating patients for infectious diseases based on clinical symptoms alone is inaccurate.1
Today, rapid tests administered at the point of care are widely available and arm HCPs with accurate real-time results that can improve their treatment decisions. These tests also address an inherent problem with the "gold standard" of lab-based culture tests, which are sensitive and low-cost, but can result in delays of up to four days because they rely on growing the bacteria or viruses.
During this delay, there is a risk for transmission of an antimicrobial-resistant organism to multiple patients. With the availability of newer, more accurate rapid diagnostics, these time frames can be reduced dramatically. For example, new technologies can dramatically reduce reporting times from several days to only minutes.
What are the advantages and disadvantages of empirically diagnosing and treating patients? How can this affect the best outcomes for the patients?
In cases where HCPs accurately assess symptoms, empirical treatment quickly links patients to the correct therapy. However, in other cases patients may be inappropriately prescribed an antibiotic that does not address the underlying infection, which not only compromises their outcomes but also increases the risk of transmitting the disease to others.
On a larger scale, the overuse of antibiotics contributes to antibiotic resistance. This is especially prevalent in hospitals, where Emergency Department physicians treating symptomatic patients often prescribe broad-spectrum antibiotics empirically in place of targeted narrow-spectrum therapies. This practice has driven an increase in resistant bacteria and the spread of healthcare-associated infections such as MRSA and C. difficile.
What rate of antibiotics are prescribed in error? What factors contribute to this?
According to the U.S. Centers for Disease Control and Prevention (CDC), up to 50% of all antibiotics prescribed are not needed or not optimally effective as prescribed".2
In many healthcare settings, diagnostic uncertainty is a limiting factor for optimal antimicrobial stewardship and can lead to the overuse and misuse of antibiotics as clinicians attempt to “second guess” a diagnosis.
Today, rapid tests are available for many of the conditions that are commonly misdiagnosed or treated empirically, and utilizing these tests would have an immediate and positive impact on decreasing the overuse of antibiotics.
A good example is Strep A. Data show that when Strep A is diagnosed empirically, it is confirmed to be the cause of the illness in only 15% - 30% of cases; however, antibiotics are prescribed in 55% - 75% of cases.3
What effect would rapid POC systems make to the way that antibiotics are prescribed?
Many studies have demonstrated that antibiotic stewardship programs that include point-of-care testing have a significant impact on the responsible use of antibiotics. In certain parts of Europe, near-patient testing is more widely implemented as part of antimicrobial stewardship, and results clearly demonstrate its effectiveness.
In parts of Scandinavia and Switzerland, a simple point-of-care test for the biomarker C-reactive protein (CRP) test is widely used and is helping physicians discern, in less than five minutes, serious illness from often self-limiting illnesses like acute bronchitis or other respiratory tract infections, which may not need to be treated by antibiotics.
In a 2011 multinational study, point-of-care testing for group A streptococcus and CRP contributed to significant reductions in antibiotic prescribing for respiratory tract infections — as much as 20% in one country.
Covering three flu seasons, a U.S. retrospective study showed that patients diagnosed with a rapid influenza diagnostic test (RIDT) were less likely to receive antibiotics compared to those who were not tested with RIDTs.
While those diagnosed with the RIDT were three times more likely to receive antivirals as those not diagnosed with RIDTs.3
Why is rapid diagnosis of patients not often discussed as a potential solution to the antibiotic resistance crisis? What impact do you think rapid POC diagnostic devices would have on the fight against antibiotic resistance?
Medical and public health organizations around the world have called on HCPs to implement antimicrobial stewardship programs to reduce the use of antibiotics. We are only now beginning to see greater discussion of the role of point-of-care testing in these programs.
Recently, Lord Jim O’Neill, the UK Commercial Secretary to the Treasury and Chair of the Review on Antimicrobial Resistance, released recommendations to fight the global threat of antimicrobial resistance (AMR).
Lord O’Neill’s landmark report is the first to focus on the role that rapid diagnostics can and should play in helping HCPs avoid prescribing unnecessary antibiotics and to narrow the spectrum of the antibiotics that are used.
It calls for high-income countries’ governments and regulators to support the use of rapid point-of-care tests by primary and specialty care providers. The report also calls on these countries to make it mandatory that by 2020 the prescription of antibiotics be informed by diagnosis, or by epidemiological data where tests are unavailable.
Why does the risk of antibiotic resistance increase over the cold & flu season?
Many patients, including children, present with respiratory symptoms during the winter months. Physicians often empirically treat these patients with azithromycin or fluoroquinolone, presumably believing that there is minimal harm in prescribing these broad-spectrum antibiotics.
However, these antibiotics do not treat viral infections like RSV, influenza or the common cold, and can leave patients vulnerable to infections such as C. difficile. In fact, a recent study found that 15% of 175 pneumonia patients treated with fluoroquinolone who did not previously have resistant microorganisms were found to have resistant microorganisms three months post-treatment.4
What recommendations would you give to help lower the rate of antibiotic resistance?
Implementation of rapid point-of-care testing is a key strategy to reduce the unnecessary prescribing of antibiotics and combatting antibiotic resistance.
Other recommendations include implementation of antibiotic stewardship programs, tracking the spread of resistant bacteria, taking infection control measures to reduce the spread of bacterial diseases, improving use of currently available antibiotics, and promoting the development of new antibiotics and new diagnostic platforms for detecting resistant bacteria.
Where can readers find more information?
The professional education site testtargettreat.com, from Alere and the Alliance for the Prudent Use of Antibiotics, provides clinical monographs, case studies and webinars on antibiotic stewardship and diagnostic strategies to support clinicians and boost global awareness of antibiotic resistance and effective interventions.
About Dr Norman Moore, Ph.D
Director of Scientific Affairs, Infectious Diseases, Alere
Norman Moore, Ph.D., is the scientific director of infectious disease for Alere. Dr. Moore plays an integral role in Alere’s antimicrobial stewardship campaign (Test Target Treat™), which focuses on educating healthcare professionals on the role of rapid diagnostics in enabling improved treatment decisions as a way to combat the antibiotic resistance crisis.
Dr. Moore holds multiple patents and was the original inventor of the rapid urinary antigen tests for Legionella and S. pneumonia, among other assays.
He has served on multiple National Institute of Allergy and Infectious Diseases (NIAID) grant committees, the Centers for Disease Control and Prevention (CDC) guideline group for rapid influenza testing, and the Clinical Laboratory Standards Institute guideline committee for point-of-care infectious disease testing, and the College of American Pathology Point-of-Care Committee.
Dr. Moore is a frequent speaker at industry events and publishes widely on topics related to antibiotic stewardship and point-of-care testing for infectious diseases.
Dr. Moore received his Bachelor’s Degree in biology and philosophy from Dartmouth College and his Ph.D. in microbiology from the University of New Hampshire.
- Monto AS, Gravenstein S, Elliott M, Colopy M, Schweinle J. Clinical signs and symptoms predicting influenza infection. Arch Intern Med. 2000;160(21):3243–3247.
- Centers for Disease Control and Prevention (CDC). Antibiotic resistance threats in the United States, 2013.
- Rapid influenza diagnostic tests increased antiviral use. J Ped Infect Dis (2013) doi: 10.1093/jpids/pit071. First published online: November 13, 2013.
- Goldstein, RC, G Husk, T Jodlowski, D Mildvan, D Perlman, and J Ruhe. Fluoroquinolone and ceftriaxone-based therapy of community-acquired pneumonia in hospitalized patients: The risk of subsequent isolation of multidrug-resistant organisms. American Journal of Infection Control. 2014. 42: 539-41