From flu to pertussis, respiratory infections are challenging to diagnose because so many share common symptoms and patients often have little useful information about how or where they were exposed. Yet because of the prevalence of these illnesses, there’s a great deal of pressure on clinical labs to generate actionable results to support the physician’s decision-making process. For example, there were more than 11 million medical visits due to influenza alone during the 2015-2016 flu season, according to the U.S. Centers for Disease Control and Prevention (CDC).1
Multiplexed molecular testing
A major advance for diagnosing these infections came with the rise of multiplexed molecular testing. PCR-based tests are now widely considered the standard method, replacing serology, tissue culture, and other conventional tests.2 That shift has made it possible for labs to return more accurate results much faster, improving physicians’ ability to get the right treatment to the patient sooner.
Molecular testing may also prevent giving patients the wrong treatments, such as prescribing antibiotics for a viral infection. In light of the growing antimicrobial resistance problem, generating sensitive and specific results in a clinically meaningful timeframe is more important than ever. Clinical labs increasingly support antimicrobial stewardship programs that aim to rein in the spread of drug-resistant pathogens by avoiding the use of antibiotics for cases in which they are not appropriate. For respiratory infections, that means confirming a viral source as quickly as possible.
An effective way to empower clinical labs to diagnose respiratory pathogens is to provide as much flexibility as possible. This is imperative for managing costs when faced with variable sample volumes and target choices, for which selection is strongly influenced by patient demographics, and reimbursement. Flexibility is important when it comes to managing lab capacity, selecting the lab’s respiratory pathogen testing algorithm, managing variation in patient demographics, and balancing the testing results with reimbursement concerns.
Test volume
Capacity is a key consideration for all labs, but respiratory testing makes this parameter more complex. Naturally, high-capacity reference labs need a very different solution than low-volume labs. However, due to the seasonality of respiratory viruses such as influenza, even low-volume labs must be prepared for significant testing spikes. To prevent unexpected peaks in demand from crippling labs—and to ensure their ability to return results in a timely manner—all clinical labs must have access to workflows that can handle stat and batch testing to increase throughput as needed, with minimal hands-on time. Systems that allow for variable throughput sample processing are especially well suited to the ebb and flow of respiratory testing.
Testing methods
As molecular assays gained traction, the option became available to test a sample for all common respiratory infections at once. This approach can be ideal for some cases, but the clinician may deem it excessive for certain patients (e.g., outpatient clinic patients with mild influenza-like symptoms during flu season with no co-morbidities and no at-risk co-inhabitants of household). Each lab has unique challenges when selecting its respiratory pathogen testing algorithm based on such things as geography and the provider and patient networks served. With many different targeted tests, as well as broad panel tests available, labs have many options; in the best-case scenario, labs can even choose from these options on a case-by-case basis. This level of flexibility is essential for optimizing patient care and accelerating time to results.
Patient demographics
Infection susceptibility varies widely between a healthy 25-year-old and an elderly patient living in a nursing home. Clinical labs need to consider variations in the population when crafting their guidelines for respiratory testing. Groups that require atypical testing can include elderly patients, children, immunocompromised patients, and those who have recently traveled to areas of the world where different respiratory infections are endemic.3 In these cases, labs may want to expand on targeted testing of flu and respiratory syncytial virus with broader testing for respiratory illnesses, including some that could be considered rare among the general population.
Reimbursement concerns
Due to the rising costs of healthcare, labs are under significant budget pressure, being asked to do more with less. Labs must balance providing testing with the necessary performance and pathogen coverage with fiscal constraints, while always staying focused on the goal of serving the needs of the patients. Historically, both private and public payers have been hesitant to cover molecular panel testing, as the panels have been considered too broad and the technology too expensive. As payers move toward value-based reimbursement, flexible solutions with clearly defined clinical utility must be identified to achieve the needs of all of these stakeholders.
Target masking
To that end, a new approach that allows for target masking is delivering more flexibility for labs as they strive to adhere to patient treatment guidelines and the dynamic reimbursement landscape. With this method, labs have access to a panel with many different respiratory infection targets, but still retain the ability to tailor testing to the specific needs of each patient. Rather than running the full panel for all patients, labs can choose which targets to test; the other targets are masked. If after the test has been run all of the selected targets come back negative, the lab may choose to unmask additional results without running the entire assay again. Labs pay only for the targets that were reported. This cost-effective approach allows labs to begin with the most likely targets and expand only in cases where those targets failed to give a useful answer.
At this year’s Clinical Virology Symposium, a clinical lab director from UF Health Jacksonville reported that her lab had saved more than $95,000 in respiratory testing in 2016 by adopting this type of platform.4 As the reimbursement landscape continues to evolve, having flexible options such as target masking allows clinical labs to achieve their diagnostic goals without having to worry about changing test platforms with each payer coverage change.
Flexibility is the key
Clearly, the concept of “one size fits all” is not appropriate for respiratory pathogen testing given the dynamic needs of clinical laboratories. When it comes to testing for respiratory pathogens, the best assays, platforms, and methods will make it easy for lab staff to adapt quickly as their needs shift depending on season, patient, cost, and other factors. For clinical lab teams and diagnostic developers in this field, flexibility should be a guiding principle.
REFERENCES
- Rolfes MA, Foppa IM, Garg S, et al. Estimated influenza illnesses, medical visits, hospitalizations, and deaths averted by vaccination in the United States. [CDC website]. https://www.cdc.gov/flu/about/disease/2015-16.htm.
- Beck ET, Henrickson KJ. Molecular diagnosis of respiratory viruses. Future Microbiol. 2010;5(6):901-916. https://www.ncbi.nlm.nih.gov/pubmed/20521935.
- Baer SL, Colombo RE, Vazquez JA. Community-
acquired pneumonia (CAP). Medscape. Jun 16, 2017. http://emedicine.medscape.com/article/234240-overview#a2. - McCarter, Y. Respiratory virus testing using VERIGENE RP Flex. ASM Clinical Virology Symposium. May 8, 2017. Savannah, GA.
