As the role of clinical laboratories grows more prominent in the diagnosis and treatment of patients with infectious diseases, there is mounting pressure on both the labs and the diagnostic tests they select. Today’s infectious disease tests must do much more than simply detect the presence or absence of a specific pathogen—they also have to be able to identify antibiotic resistance markers, scale up or down based on demand, support rapid assay development as new threats emerge, secure reimbursement coverage, and much more.
And, of course, this all must be done in a timeframe that enables meaningful clinical decision-making. Because rapid molecular diagnostics have shorter turnaround times than conventional assays, they are the most likely option for meeting enough of these requirements to be viable for routine lab use.
With all of these needs, perhaps the most important feature that clinical lab experts should look for when considering an infectious disease test is flexibility. Diagnostic platforms and assays that provide flexible scalability, pricing, and testing options can address the many competing constraints faced by busy clinical laboratories. On the other hand, systems without such flexibility will almost always fall short of meeting the demands of today’s labs. By focusing on flexibility as a key requirement, lab managers can enable their teams to achieve greater success both increasing efficiency and for treating patients.
Infectious disease tests offer a few types of flexibility, and while all are useful, many tests come with multiple limitations. Here’s a quick review of the various factors that can help clinical lab managers determine which are most important for their patients and testing needs:
Certain infectious diseases, such as influenza, have seasonal spikes. While labs need to be able to offer tests for these pathogens at any time of year, it is essential to have a testing platform that allows the ability to scale up or down depending on current demand. A one-assay-at-a-time system that works nicely in the off-season would be easily overwhelmed once flu season begins. Similarly, a high-throughput system that works well for high-demand use would be inefficient during the off-season. For these types of tests, labs might look for multiplex platforms that allow both stat and batch testing—making it easier to scale up and down as needed.
Among molecular diagnostics, the pendulum has swung back and forth between syndromic and targeted testing. Ideally, labs wouldn’t have to choose one or the other—the best multiplex molecular tests allow clinical experts to determine the range of testing for each patient’s specific needs. The recent development of flexible testing offers labs new options for assay content. With flexible testing, clinical labs run a syndromic-style panel, but only report results for the specific pathogens ordered by a healthcare provider. If all of those results are negative, the provider can request immediate unmasking of additional results from that test without rerunning it, and add results until a positive result is detected. Labs only pay for the results that are reported, helping to minimize testing costs for their patients. This built-in pricing flexibility is just as important as the actual testing flexibility. Even if flexible testing is not available, clinical lab managers can still focus on diagnostic platforms that support both targeted and syndromic panels for optimal utility.
Because antibiotic resistance is one of the most pressing public health threats, clinical labs must implement assays that can identify not only the causal pathogen, but also its drug resistance markers. Culture-based diagnostics simply cannot provide these answers quickly enough to meaningfully impact patient treatment. Molecular tests offer the flexibility to perform both organism identification and resistance detection—often in the same assay—with no extra processing time required.
IVDs and LDTs
While the testing portfolios in some clinical labs are heavily skewed towards lab-developed tests (LDTs), others focus primarily on commercially available, FDA-cleared in vitro diagnostic (IVD) assays. With lab space at an increasing premium, too often, lab directors must choose diagnostic platforms that support only one of these testing types. A system that can run both IVDs and LDTs would maximize efficiency while minimizing the physical footprint of these instruments—a feat made possible by streamlining thermal cycling profiles so they are universally adapted for all assays. This allows labs to run their favorite off-the-shelf IVDs, but also to respond to emerging infectious disease threats by quickly developing new LDTs.
Ease of use
Systems that are difficult to learn or temperamental to operate will inevitably become obsolete. If a test is nearly impossible to run, the most flexible platform in the world is worth very little to a clinical lab. Diagnostic platforms that are push-button easy are becoming almost essential, especially because they allow lab members to delegate their time across all of their tasks more efficiently. Automated, load-and-go systems also reduce the opportunity for error, and can even send results to a central monitoring system, eliminating the need to view results on the actual instrument. Ease of use is increasingly important considering the continued shortage of medical laboratory professionals in the workforce. The American Society of Clinical Laboratory Science reported an average vacancy rate of 7.3% in a 2016–2017 survey. Some reasons for this shortage include retirement of an aging workforce, increased demand for laboratory services, changes in laboratory technology, and vacancy rates that exceed the number of new graduates.1
On the Horizon
Looking ahead, it seems safe to predict that the demand for infectious disease testing services will continue to grow, and the patient’s journey will be increasingly reliant on these test results. Lab managers must make careful and strategic choices about which diagnostic technologies are worth investing in. By focusing on flexibility, in addition to specific test requirements, labs can ensure that the platforms they choose will benefit both their workflows and their treatment strategies, while adhering to increasingly stringent reimbursement policies. As the infectious disease testing field evolves, clinical labs that can adapt to evolving needs will be best equipped to deliver reliable, clinically actionable results to physicians and patients.
1. Flanigan, J. Addressing the Clinical Laboratory Workforce Shortage. The American Society for Clinical Laboratory Science. Cited 2020 Feb. Available from: https://www.ascls.org/position-papers/321-laboratory-workforce/440-addressing-the-clinical-laboratory-workforce-shortage.