The Diagnostic Gap 

Antibiotic overuse in hospital and outpatient settings contributes significantly to the increasing prevalence of antibiotic resistance. At the heart of this problem is the challenge to accurately distinguish between bacterial infections (which warrant antibiotic therapy) and viral infections (for which antibiotic treatment is not required). Although current diagnostic tools for facilitating appropriate use of antibiotics are valuable in many clinical situations, they are often inadequate. 

Extended time to results

Existing diagnostic tools often require hours to days to provide information, whereas physicians typically need to decide whether to prescribe antibiotics within minutes, ideally during the patient’s visit to his/her primary care physician.

Failure to diagnose when the infection site is inaccessible

Available diagnostic technologies usually require direct sampling of the pathogen. Such sampling is often unfeasible if the infection site is inaccessible, for example in the case of sinusitis, middle-ear infection, bronchitis, etc.

False-alarms due to bacterial carriage

Today’s diagnostic technologies generally search for the presence of specific bacteria. However, many bacteria live as natural flora within our bodies without causing disease. For example, S. pneumonia is in the upper respiratory tract natural flora of 70% and 25% of healthy children and adults, respectively. Therefore, a diagnostic approach based on detecting specific bacteria can lead to false alarms and consequently over-prescription of antibiotics.

These limitations result in a diagnostic gap, which in turn often leads physicians to either over-prescribe (“just-in-case”) or under-prescribe (“watchful waiting”) antibiotics, both of which adversely impact patient care and health economics.

1. Little and Williamson, BMJ, 1994. 
2. Spiro et al., JAMA, 2006. 
3. Little P, BMJ, 2005.