CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
Anne Ford
November 2016—Raquel M. Martinez, PhD, D(ABMM), is very happy in her role as director of clinical and molecular microbiology at Geisinger Health System, Danville, Pa. But in another universe she might have applied her skills to television journalism instead. That’s because like any good interviewer, she not only values sensitivity and specificity but also is fond of asking crucial questions such as “When?” “Who?” and “Where?”
That Mike Wallace-like skill set was on full display during “NAATs for Respiratory Pathogen Detection: Does the How, When, and Where Matter?” a talk she gave at the ASM Microbe meeting earlier this year.
A yearly algorithm, a triage system, and a dashboard keep molecular testing for respiratory pathogens on track at Geisinger. Random-access testing and a reduced TAT are saving the health system millions, says Dr. Martinez (left), here with Barb Heiter, BS, MT(ASCP).
In her presentation and in conversation with CAP TODAY, Dr. Martinez outlined Geisinger’s extensive efforts in respiratory pathogen detection, the goal of which is to determine exactly which assays should be used for respiratory pathogen nucleic acid amplification, when those assays should be performed, and in what settings, and which include the use of a diagnostic algorithm. For Geisinger, the how, when, and where do matter—and they matter very much indeed.
Geisinger, a fast-growing health network with 12 hospital campuses, aims to standardize its laboratory processes and adopt best practices in microbiology. Donna M. Wolk, MHA, PhD, D(ABMM), Geisinger’s system director for clinical and molecular microbiology, elected in January 2013 to stop offering rapid antigen testing on the grounds that such testing is inferior to nucleic acid amplification testing. “Geisinger’s comparison of molecular and antigen testing confirmed published reports that the antigen test’s sensitivity and specificity were lacking, and we never looked back,” Dr. Martinez says.
Centers for Disease Control and Prevention guidelines say antigen testing results should be confirmed with a molecular method, owing to the speed and accuracy of those molecular methods. “And we are baffled that some hospitals and many urgent care clinics and office laboratories continue to use inaccurate antigen-based methods. Antigen testing, prone to both false-negative and false-positive results, serves only to delay an accurate result and diagnosis,” Dr. Martinez says. She and Dr. Wolk are committed to providing their patients and providers with faster and more accurate methods, she says, and to proving the downstream impact of rapid technology. “Our advice to anyone fielding requests to continue performing rapid antigen testing is ‘Just say no.’”
In 2009, when the laboratory still performed culture and DFA for respiratory pathogen testing, the average time to result was 67.13 hours—nearly three days. In 2011, a batch-based multiplex PCR was implemented. “We batched them once a day, Monday through Friday, and we were able to decrease our turnaround time by almost 30 hours,” Dr. Martinez says. Then, in late 2012, the laboratory adopted a non-batched multiplex test for respiratory pathogens, and the average turnaround time dropped—first to 11.68 hours, then to 5.9 in 2013 by distributing technology to more of the hospitals, and then to where it stands now at the end of the 2016 respiratory season, 2.83 hours.
With the goal of reducing large-panel testing—thereby reducing costs, lowering turnaround time, and maximizing efficiency—the Geisinger laboratory collaborates with infectious disease clinicians, pharmacists, and infection prevention teams to support an algorithm that defines which patients should receive which type of nucleic acid amplification testing and at what time of year. The algorithm is revised annually before the start of flu season. Samples are collected and submitted in universal transport media, with nasopharyngeal swabs preferred for upper respiratory tract samples and 1 mL bronchoalveolar lavage for lower respiratory tract samples. Samples from inpatients, emergency room admissions and observation units, and high-risk outpatient groups are tested with a multiplex PCR panel (available year-round). Samples from low-risk outpatients and non-admitted ER patients are tested with abbreviated panel testing for influenza A and B and respiratory syncytial virus (available Nov. 1–April 30, when those viruses are highly prevalent).