Charlotte, NC—Taking a sample of a single stool and using multiple PCR panels can identify more acute gastroenteritis pathogens—and do so more rapidly—than a conventional workup, according to a new study. The process was found to be effective at detecting diarrhea-causing Escherichia coli and enteric viruses, among others.

The new study on better ways to identify acute gastroenteritis involved nearly 40,000 hospital visits from a geographically diverse healthcare database. It was published in the Journal of Clinical Microbiology.

Using multiple PCR panels, “Fewer patients received antibiotics, required additional visits or diagnostic tests, or were hospitalized for gastroenteritis within 30 days [of index visit],” explained Rena C. Moon, MD, MPH, principal research scientist, PINC AI Applied Sciences in Charlotte. She pointed out that conventional workups often include testing a stool culture for a single suspect species of pathogen, use of a single pathogen PCR test, or identifying a pathogen using microscopy, immunology, or an ova and parasites test.

“Earlier studies showed that large multiplex PCR panels improve the speed and accuracy of diagnostic testing in patients with acute gastroenteritis, but their impact on costs and clinical outcomes had been uncertain,” explained coauthor Ferric C. Fang, MD, professor of laboratory medicine, pathology, and microbiology at the University of Washington School of Medicine in Seattle. “Our study shows that the benefits of multiplex panels can be achieved without increasing overall healthcare costs, and also facilitates more appropriate use of antibiotics.”

“This study illustrates the power of big data to analyze the healthcare impacts of diagnostic testing, and help laboratories select testing approaches that improve meaningful clinical outcomes,” Dr. Fang said.

The retrospective observational study sought to assess the relationship between diagnostic method (traditional work-up [TW], multiplex PCR panel with <12 target pathogens [PCR <12], or multiplex PCR panel with ≥12 target pathogens [PCR12]), and diagnostic yield, healthcare resource use (HRU), and cost in adult outpatients visiting U.S. hospitals for acute infectious gastroenteritis (AGE).

The researchers used data from PINC AI Healthcare Database from January 1, 2016, to June 30, 2021, analyzing adult patients with an AGE diagnosis and stool testing performed during an outpatient visit.

The results indicated that, among 36,787 patients, TW was most often performed (57.0%), with PCR12 testing more frequent in patients from large, urban, and teaching hospitals, compared with TW (all P <.01).

“PCR12 was associated with a higher mean index visit cost (by $97) but lower mean 30-day AGE-related follow-up cost (by $117) than TW,” according to the authors, who added, “Patients with PCR12 had a lower 30-day AGE-related hospitalization risk than TW (1.7% versus 2.7% P <.01).”

The study noted that, among the 8,451 patients with microbiology data, PCR12 was associated with:

• Fewer stool tests per patient (mean 1.61 vs. 1.26)
• Faster turnaround time (mean 6.3 vs. 25.7)
• Lower likelihood of receiving in-hospital antibiotics (39.4% vs. 47.1%, all P <.01) than TW.

In addition, according to the researchers, a higher percentage of patients with PCR12 had a target pathogen detected (73.1%) compared with PCR <12 (63.6%) or TW (45.4%, P <.01). “Thus, we found that large multiplex PCR panels were associated with lower 30-day AGE-related follow-up cost and risk of AGE-related hospitalization, and increased diagnostic yield compared to TW,” they wrote.

Background information in the article advised that diagnostic evaluation for AGE is recommended during known or suspected outbreaks, in immunocompromised patients at increased risk for complications, and for patients at a high risk of spreading the disease to others.

“In addition, diagnostic stool testing can enable specific directed therapy and provide clinical benefits in patients with dysentery, moderate-severe illness, or symptoms lasting >7 days,” the authors add.

They suggest that traditional diagnostic methods, such as bacterial culture, antigen testing, microscopy with and without special stains and immunofluorescence, can be time-consuming and difficult to coordinate laboratories. “Traditional methods also have lower sensitivity, require trained microbiologists to perform), and fail to identify a microbial etiology in most cases of AGE,” the researchers wrote. “For patients in whom diagnostic stool testing is indicated, such limitations may adversely impact health care costs and clinical outcomes—isolation protocols may be inappropriately applied, antibiotic administration may not be timely, and some patients may require additional testing or hospitalization due to delays in diagnosis.”

On the other hand, multiplex gastrointestinal (GI) PCR panels, including bioMérieux BioFire FilmArray GI Panel, Luminex xTAG GI Pathogen Panel, Luminex VERIGENE Enteric Pathogens Test, Applied BioCode GI Pathogen Panel, BD MAX Enteric Bacterial/Viral/Parasite Panels, and Hologic Prodesse ProGastro SSCS Assay, have the ability to simultaneously detect many of the common agents of AGE, including bacteria, parasites, and viruses. “Such panels can facilitate accurate and timely identification of AGE pathogens to reduce transmission and appropriately target therapy to shorten the duration of symptoms, prevent complications, and optimize health care resource use (HRU),” according to the study.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.

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