Researchers evaluated the performance of microbial cell-free DNA testing for the diagnosis of head and neck infections in pediatric patients

Ear, nose, and throat (ENT) infections are one of the most common reasons for prescribing antibiotics to children. Although some ENT infections can be simple to identify and diagnose, others are more severe that require immediate attention and care. To identify the microbes causing the infection, clinicians collect and analyze samples using surgical procedures and traditional culturing methods. However, the results of culturing assays take time to be available, and doctors are forced to prescribe broad-spectrum antibiotics in the meantime. This in turn leads to increased healthcare costs and complications such as hospital-derived infections in children. Therefore, a diagnostic assay with lesser turnaround time would greatly help clinicians to identify pathogens quickly and allow for better and timely clinical interventions in pediatric patients.

Recent studies in this field have indicated microbial cell-free DNA (mcfDNA) testing as a viable assay capable of identifying pathogens from the bloodstream. However, this technique has not been studied for use in severe infections of the head and neck regions in children.

To fill this gap, a group of researchers led by Assistant Professor Kara Meister from the Stanford University School of Medicine, USA, studied the utility of mcfDNA testing in predicting causative organisms behind head and neck infections in children. Their findings were published online on January 6, 2025, in Pediatric Investigation. Dr. Meister explains the rationale behind their study, “The head and neck area has several highly vascularized regions such as the sinonasal cavity and the oropharynx. Therefore, we anticipate that significant infections in these regions will produce enough mcfDNA signal to be detectable on commercial testing.”

The researchers conducted a prospective, diagnostic study on 26 pediatric patients admitted at the Lucile Packard Children’s Hospital, suspected with acute and complex infections of the head and neck. 2.5 milliliters of blood from each patient was submitted for mcfDNA testing. A control population of 99 patients were also selected who were admitted for surgical procedures not pertaining to infections such as cochlear implants. “The primary objective of this study was to examine the diagnostic performance of mcfDNA testing as compared with microbiological and clinical data including conventional microbiological diagnostic tests, radiological studies, and clinical adjudication,” Dr. Meister offers to explain the main goal of their study.

The results from mcfDNA testing were classified as ‘Consistent with infection’, ‘Unclear’, ‘Not consistent with clinical presentation’, or ‘Contaminant’. The researchers found that in seven out of 26 patients (26.9%) the mcfDNA testing predicted infectious organisms consistent with that of traditional culturing tests. These patients had acute, invasive infections, with most of them not being exposed to antibiotics at the time of testing. However, in two out of 26 patients (7.7%), a possible causal organism was identified via mcfDNA testing but the findings differed from that of traditional culturing tests. In these cases, the identity of the causative organism was unclear.

For 10 patients no results were found from mcfDNA testing, and were classified under ‘Not consistent with clinical presentation’. Five of these patients had prior antibiotic exposure and had less severe infections. However, in seven out 26 patients (26.9%) mcfDNA testing showed significant contamination by other pathogens and were classified as ‘contaminant’ results. Interestingly, the researchers reported that some patients in the control population also showed results for mcfDNA tests. In fact, they were able to detect 25 distinct pathogens from the control population.

Dr. Meister comments on the results of their study, “Overall, while mcfDNA testing showed promise in predicting causative organisms in some cases of acute, invasive infections, its utility was variable in this cohort and was potentially influenced by factors such as antibiotic exposure and the possible influence of contamination.”

To summarize, plasma based mcfDNA testing offers a less invasive and faster alternative to standard testing methods. While further research is required to evaluate the optimal use and interpretation of mcfDNA tests, this study sheds light on the potential application of mcfDNA testing for detecting specific pathogens leading to targeted antibiotic therapies in pediatric patients.
Reference
Title of original paper: Efficacy of microbial cell-free DNA testing for detecting pathogens in pediatric patients with head and neck infections—An initial study
Journal: Pediatric Investigation
DOI: 10.1002/ped4.12462

About Dr. Kara Meister
Dr. Kara D. Meister, MD, FAAP, FACS is a pediatric otolaryngologist and head & neck surgeon at the Stanford University School of Medicine, USA, and now she serves as an Assistant Professor in their Department of Otolaryngology. She received her medical degree from the Medical University of South Carolina and completed her otolaryngology residency at the University of Pittsburgh. Dr. Meister’s research interests include thyroid cancer, head & neck masses, and Graves' disease. She is specially interested in the influence of the environment and pollutants (such as microplastics) on children’s health. She currently serves as the Associate Clinical Chief of Pediatric Otolaryngology and enjoys advocacy work with the American Academy of Pediatrics Button Battery Taskforce.