Determining whether a microbe is actually causing disease has become one of the most important and challenging questions in infectious diseases. New diagnostic technologies are generating unprecedented amounts of data, but clinicians still face a familiar dilemma: Is what’s being detected actually responsible for a patient’s illness?
That question is the basis of “Is This Infectious? Pediatric Physician Scientists on the Case!,” Saturday, Oct. 24, at 10:30 a.m. ET, featuring speakers Sanjay Jain, MD, professor at Cincinnati Children’s Hospital Medical Center; Elizabeth Ann Enninga, PhD, associate professor of obstetrics and gynecology at Mayo Clinic College of Medicine and Science; and Charles Langelier, MD, PhD, professor at University of California San Francisco.
Moderated by Allison Bartlett, MD, MS, professor of pediatric infectious diseases at University of Chicago Medicine, and Lilliam Ambroggio, PhD, MPH, professor of pediatrics at Children’s Hospital Colorado, the session will showcase how emerging technologies are helping investigators distinguish infection from noninfectious disease states and generate insights that can improve patient care.
Dr. Jain will look at pathogen-specific molecular imaging, an emerging approach designed to identify infections noninvasively and with greater precision than conventional diagnostic methods.
The technology seeks to address a longstanding challenge in medicine: distinguishing between infection and other causes of inflammation. By visualizing pathogens directly, rather than relying solely on cultures or indirect markers of infection, clinicians may be able to achieve greater diagnostic certainty and make more informed treatment decisions.
The presentation will highlight how advances in imaging science are moving beyond the simple detection of disease and toward a deeper understanding of where infections are occurring, how extensive they are and whether patients are responding to therapy. As diagnostic capabilities continue to evolve, such approaches could help reduce unnecessary antimicrobial use while improving the accuracy and timeliness of care.
Looking Beyond Pathogens in the Placenta
Dr. Enninga will focus on chronic villitis, a placental inflammatory condition that can have significant consequences for both mothers and children.
Using metagenomic approaches developed in her laboratory, Dr. Enninga and colleagues are investigating a fundamental question: Is chronic villitis caused by infection, or is something else driving the inflammation? The answer has important implications for counseling patients about future pregnancies and long-term outcomes.
“If it’s not the infectious etiology or the infectious cause, we are finding that that has significant ramifications or consequences for the next pregnancy,” Dr. Enninga said. “We want to be able to give our clinician colleagues that are seeing these moms the best information so that they know what to watch out for and how to counsel their patients.”
Her team’s findings suggest that most placentas diagnosed with villitis do not have an infectious cause. At the same time, advances in sequencing have revealed previously unrecognized viral associations, including cases involving enterovirus infection.
The work is also revealing why clinicians should pay closer attention to placental pathology. Dr. Enninga said emerging data from thousands of cases suggest children exposed to villitis experience higher rates of hospitalization, antibiotic use, infections and adverse neurodevelopmental outcomes in early childhood.
“We’re starting to realize there’s actually a treasure trove of information about that pregnancy just hiding in plain sight in that placenta,” she said.
Differentiating Colonization From Infection
Dr. Langelier’s presentation will tackle another question with major implications for pediatric care and antimicrobial stewardship: How can clinicians tell whether a detected respiratory pathogen is causing disease or simply residing harmlessly in the airway?
Dr. Langelier and colleagues studied more than 300 critically ill children, using metagenomic sequencing to simultaneously evaluate pathogens, the respiratory microbiome and the host immune response. Their goal was to distinguish true infection from incidental pathogen carriage, a common phenomenon that frequently leads to antibiotic exposure.
“Someone comes into the hospital, they have some type of respiratory symptoms. You detect anything, the intuition is to treat it just in case that’s causing the problem,” Dr. Langelier said. “It turns out that a large fraction of people just carry pathogens in the respiratory tract, even in states of health.”
The study found markedly different biological signatures between infection and colonization. True infections were associated with strong host inflammatory responses and disruption of the respiratory microbiome, while patients with incidental pathogen carriage more closely resembled uninfected controls.
"There’s this huge unmet need for a test to distinguish these two states: infection from incidental pathogen carriage or colonization,” Dr. Langelier said.
Researchers hope the findings could eventually support rapid diagnostics based on a limited set of biomarkers rather than comprehensive sequencing, helping clinicians make more informed treatment decisions while reducing unnecessary antibiotic use.