Advances in Point-of-Care Testing and Tips for Clinicians

The recent American Society for Microbiology (ASM) Microbe 2017, held June 1-5 in New Orleans, Louisiana, included presentations on point-of-care (POC) testing in infectious disease. One study, for example, supports the value of measuring procalcitonin in-house for same-day results to guide treatment, save antibiotic use, and improve the quality of care.¹

According to other findings, the rapid Nanosphere Verigene® Blood Culture Gram-negative panel could be beneficial in an antimicrobial stewardship program, and targeted panfungal polymerase chain reaction (PCR) amplicon sequencing could facilitate accurate and timely identification of fungi causing invasive fungal disease when conventional methods fail to produce a diagnosis.^2,3 Additional results indicate that PCR tests may be quick and sensitive tools for the detection of Staphylococcus aureus and methicillin resistance in pediatric patients.⁴

Also presented at the meeting was a report from the American Academy of Microbiology called Changing Diagnostic Paradigms for Microbiology, which reviews the latest developments in POC and near-patient testing and provides recommendations on their use in various clinical settings.⁵ 

To learn more about the report and the state of POC testing in the field, Infectious Disease Advisor interviewed Melissa B. Miller, PhD, D(ABMM), F(AAM), the steering committee chair of the colloquium that developed the document. Dr Miller also holds the following titles at the University of North Carolina at Chapel Hill School of Medicine: professor in the department of pathology & laboratory medicine; director of the clinical molecular microbiology laboratory; and associate director of the clinical microbiology-immunology laboratory.

Infectious Disease Advisor: What prompted the creation of the new report? 

Melissa B. Miller, PhD, D(ABMM), F(AAM): Clinical laboratories are currently facing many challenges such as workforce shortages, healthcare consolidation, and reimbursement. In addition, diagnostic technology has become so advanced that results can be available much more quickly than is often possible in a centralized testing facility. In some cases, rapid molecular tests have become just as accurate as tests available in large laboratories.

We realized that combining the challenges our central laboratories face with the opportunities that rapid molecular POC testing offer may have a positive impact on both areas. We wanted to develop recommendations as this technology matures and starts to be used at the site of the patient encounter so we can assure the best possible outcome for patient care. 

Infectious Disease Advisor: What are some of the top recent developments in the areas of POC and near-patient testing for infectious diseases?  

Dr Miller: The greatest development is molecular POC and near-patient testing. Many of our laboratories have been using moderate complexity molecular tests that are conducive to near patient testing, but often still performed in the central laboratory. Although results are faster than many older molecular tests that were performed only once a day, the central microbiology laboratory is often not able to achieve the same quick turnaround time that might possibly be obtained in a physician’s office. By placing these molecular tests in settings such as the emergency department or intensive care unit (ICU), they may have greater impact on clinical decision making. 

What is very exciting is that we now have Clinical Laboratory Improvement Amendments (CLIA)-waived molecular tests that can be performed in physician offices. These tests are simple to perform, do not require a laboratorian, and do not require that specimens be sent to a central laboratory. While we have had CLIA-waived tests for infectious disease for a long time — such as influenza or strep rapid tests — they did not perform as well as tests done in the central microbiology lab. Now these tests are molecular and are just as accurate as the tests we do in the main microbiology lab. 

Infectious Disease Advisor: What should be the next steps in terms of research and development in this area?

Dr Miller: The technology is here — tests are being developed that perform just as well as tests we do in the laboratory. We need more highly accurate molecular POC tests on the market for infectious diseases. What would be particularly exciting is a test that combines pathogen and host markers to accurately determine infection vs noninfection and bacterial vs viral infection. Research in this area was highlighted at Microbe 2017. 

The colloquium participants spent a significant amount of time discussing the need for studies investigating patient outcomes and the cost-effectiveness of these tests after implementation. We don’t want to implement tests just because they are fast; we want to implement tests that are going to have a positive impact on patient care. This may be deciding whether to use an antibiotic vs no antibiotic, which could have an impact on our efforts in fighting antimicrobial resistance, or identify an outbreak sooner, which could have an impact on entire communities through public health measures. The opportunities are exciting, but we should carefully consider not only the potential impact of using POC testing but also the potential challenges. That is the goal of the colloquium report. 

Infectious Disease Advisor: What are the immediate takeaways for our audience of infectious disease clinicians?

Dr Miller:

• With the implementation of POC testing, we will need to reassess patient workflow through clinical practices to allow for the most efficient use of these tests and minimize patient wait time. 
• It will be imperative to have POC and clinical microbiology experts involved in the process to enable safe and effective use of the tests and promote proper test interpretation. 
• Physicians should discuss the available tests with a clinical microbiologist as all tests are not created equally.
• Physicians implementing these tests in the clinic setting should ensure that results are reported in the patient electronic medical record.
• This is an exciting time for infectious disease diagnostics! We have the opportunity to work together to enhance the patient encounter by offering advanced diagnostics at the site of visit. However, there are considerations such as specimen collection, which test to use, and procedural cautions, such as contamination, which are important.
• We will need our clinical colleagues’ help to perform outcome studies aimed at determining the cost-effectiveness and impact on patient outcome of these tests.

References

1. Patel S, Akpoji U, Wilson BM, et al. Turnaround time of procalcitonin result is key to improve antibiotic use at a VA medical center. Presented at: American Society for Microbiology (ASM) Microbe 2017; New Orleans, Louisiana; June 1-5. Session 042; Presentation 196.
2. Beckman M, Haslam D, Courter J, Washam M, DeBurger B, Mortensen J. The reliability of the nanosphere verigene gram-negative panel for use in an antimicrobial stewardship program in a pediatric hospital. Presented at: American Society for Microbiology (ASM) Microbe 2017; New Orleans, Louisiana; June 1-5. Session 042; Presentation 201.
3. Gomez CA, Budvytiene I, Zemek A, Banaei N. Accuracy of panFungal PCR sequencing for diagnosis of invasive fungal disease directly from clinical samples. Presented at: American Society for Microbiology (ASM) Microbe 2017; New Orleans, Lousiana; June 1-5. Session 266; Presentation 6.
4. Wang H, Antonara S, Salamon D, Burch C, Leber AL. Direct detection of Staphylococcus aureus and methicillin resistance in a variety of pediatric samples using laboratory-developed PCR assays. Presented at: American Society for Microbiology (ASM) Microbe 2017; New Orleans, Lousiana; June 1-5. Session 058; Presentation 440.
5. Diagnostic paradigms for microbiology, May 2017. American Academy of Microbiology. Changing. Washington, DC. https://www.asm.org/index.php/colloquium-reports/item/6421-changing-diagnostic-paradigms-for-microbiology Published May 24, 2017. Accesses June 8, 2017.