Summary
Analysis
Most US hospitals continue to use the insensitive EIA tests for C. difficile despite the introduction of superior tests. The most recent entrant to this niche is Cepheid, whose test runs in less then an hour, and has the advantage of high ease-of-use in a single disposable cartridge. The test can run simultaneously on the GeneXpert, along with a variety of other clinically relevant PCR-based tests. Cepheid is beginning to build a useful platform for hospitals ready to support rapid diagnostics. This platform enables real-time decision processes, which aid the clinician to use the appropriate antibiotic regimen, whilst reducing inappropriate antibiotic usage. The new C.diff. assay does not specifically identify the epidemic high-toxin producing strain, which would add to it's usefulness.
From the perspective of the patient, having the correct diagnosis is highly desirable, and allows the physician to build a more secure relationship. C. diff causes about 30,000 deaths annually in the US. The C.diff EIA currently in use is known to have inaccurate results, and often is ordered on several stool specimens to try to increase the yield. In severe disease, getting the right diagnosis fast and accurately is critical. As physicians we need to think hard about continuing to use the EIA, which adds a cloud of uncertainty to the physician-patient relationship in these tumultuous times in healthcare.
Currently, larger diagnostic companies are losing market share to smaller companies. For example, Becton-Dickinson offers a C. diff test, but it is run in batches on an older PCR-based platform, actually manufactured by Cepheid. Numerous startup companies are searching for ways to make microbiologic testing technologically up-to-date.
An over-arching question in diagnostics today revolves around adoption rates of newer, faster platforms. Will the GeneXpert be widely adopted by hospitals and reference labs in an era of cost-cutting and belt-tighting? It is difficult to predict the future, but today’s disruptive diagnostic technologies are likely to be increasingly attractive as part of the change paradigm we are seeing healthcare today. Evidence-based outcome trials likely will drive the adoption of innovative tests into medicine in the very near future.
