By Dr. Avishay Bransky
Decentralized diagnostic testing is a fundamental component of a successful pandemic outbreak containment strategy. It is relevant at every stage of the outbreak, from initial detection to eventual resolution, as each individual pathogen presents specific diagnostic challenges.
The recent outbreak of COVID-19 has revealed significant deficiencies in diagnostic tools, which play a major role in managing the spread and treatment of this virus. It is important for us to learn from this situation to adapt in the near and long term, to ensure we are prepared for a future that could potentially hold even more lethal outbreaks.
Current Diagnostic Challenges in COVID-19 Management
There are several challenges that healthcare systems are facing as a result of the diagnostic tools currently in use for managing the COVID-19 crisis. The complete blood count (CBC) test is crucial to managing the treatment of coronavirus patients, as there are numerous indicators within this standard test that can help us identify the stage of the disease and its severity. It is also a fundamental tool in patient monitoring and clinical decision making. Some of these decisions become a matter of life and death, such as determining when to intubate, if a patient needs to be moved to the ICU, or whether antibiotics are needed. This test needs to be performed regularly, as the markers provided in a CBC test can help measure how the immune system is responding. There is currently no feasible point-of-care option to efficiently perform these tests regularly and rapidly.
Rather, the centralized nature of current lab testing leads to a workflow challenge that places healthcare workers and other patients at considerable risk of infection due to the lacking point-of-care solution. While there are point-of-care diagnostic devices in place for other elements of diagnosis, including for the measurement of blood gasses and chemistry, for the staple CBC test, the benchtop analyzers currently available and in use are neither mobile nor are they simple to use so as to meet point-of-care testing requirements for pandemic management. These benchtop analyzers, which sometimes act as POC diagnostic systems in the absence of a real solution, are complex, and require installation and trained technicians to operate them. Though benchtop analyzers can deliver results quickly, they are not suited for many of the care settings utilized during this pandemic, including bio contaminant units and secluded wards within hospitals. Therefore, CBC samples currently need to be sent to a central lab, making the turnaround time lengthy, which may put patients at an even greater risk.
Intensified COVID-19 testing has also led to shortages of testing reagents globally, both for COVID-19 and for other diagnostics. These supply issues pose a major barrier to effective pandemic management as well. The current systems in use require a sufficient supply of reagents to operate, and a lack of them can cause major delays in diagnosis and treatment.
The availability of true point-of-care solutions to decentralize diagnostics and provide rapid CBC testing would greatly improve the current situation being faced worldwide. The lack of affordable and effective diagnostics has been described as one of today’s most serious health security blind spots. There is a great need to implement innovative diagnostic technologies that are affordable and accessible.
Diagnostic Methods to Support Diagnosis and Clinical Decision Making
Rapid point-of-care CBC testing is essential for containment of outbreaks, even in the presence of an effective vaccine. There are two specific areas where point-of-care testing can assist in the current pandemic, and in any similar situation we may face in the future. The first is in initial diagnosis and screening. The second is in treatment management.
The tests for these two situations are different. For diagnosis, polymerase chain reaction (PCR) tests must be used. The PCR test is the most widespread and most specific diagnostic test for determining whether someone is currently infected with coronavirus. In the United States, nearly 1 million people have tested positive for coronavirus using the PCR test.
However, for treatment management, blood gas, blood chemistry and complete blood count (CBC) tests need to be performed regularly in order to analyze a number of indicators that can help to identify the stage of the disease and its severity, as well as assist in making clinical decisions. To gauge a COVID patient’s status, level of infection and immune system response, having data on lymphocytes, hemoglobin, platelets, and immature cell counts is crucial. For example, low lymphocyte levels and high white blood cell and immature cell counts have been shown to correlate to disease progression and severity. Having access to simple-to-use and portable point-of-care blood diagnostic solutions could alleviate the challenges faced by healthcare systems trying to contain and manage pandemic outbreaks.
Shortening diagnostic results delivery from the several hours it currently takes with centralized lab diagnostics, to a mere minute with a stronger and faster system would give care teams the ability to quickly assess patients’ needs and make decisions. The solution must be robust, portable and with a small footprint, and must be accessible. The ease of use of such a system would be paramount, ensuring that any member of the care team could perform the test easily, without requiring the presence of a technician.
Furthermore, a true point-of-care solution would eliminate the current workflow challenges facing care teams, which not only lengthen the time to capture diagnostic results, but also put healthcare workers and other patients at increased risk of infection. This is because the current workflow involves couriers running between labs and care units, walking through the hospital, using elevators and stairwells, or transporting blood samples via a pneumatic tube system, risking accidental contamination. Not unexpectedly, medical literature has already made clear that POC diagnostics would be the ideal solution in this pandemic to minimize the exposure risks inherent in the current workflow.
The reagent shortages can be alleviated as well. Rapid POC diagnostic innovations include the concept of “lab-on-a-cartridge” technology, allowing for fully automatic blood sample processing. Disposable cartridges with automatic sample preparation for point-of-care CBC testing can include all necessary reagents and are completely factory-calibrated. The reagents and sample remain safely within the cartridge during and after testing, preventing cross-contamination. With reagents built into the cartridge itself, there is no wastage, as only the volume of reagent required is included. In fact, with advanced hematology analyzers that utilize such cartridges, up to twenty times less reagent can be used, compared to the higher volume required with standard analyzers.
It’s clear that CBC testing must be untethered from the central lab with rapid and easy to use point-of-care devices to meet the quickly evolving circumstances inherent to pandemic situations now, and in the future. The importance of decentralized diagnostics in epidemic preparedness cannot be underestimated. Integration of effective point-of-care CBC testing into existing preparedness systems, and an overall strengthening of healthcare system diagnostic capacity will lead to faster containment of future outbreaks, with the potential to save many lives and substantially reduce the burden of centralized diagnostics.
Avishay Bransky, Ph.D., CEO and co-founder of PixCell, is an expert in microfluidics, with extensive industrial experience in applied physics, software and systems engineering. He is one of the inventors of the Viscoelastic Focusing technique, cell analysis methods and the microfluidic based cartridge. Dr. Bransky holds a B.A. in Physics, B.Sc. in Materials Engineering, and a Ph.D. in Biomedical Engineering, all from the Technion Israel Institute of Technology.