Researchers have identified a promising way to predict bloodstream infections in children with high-risk leukemia days before the infection would be diagnosed using current standards of care. The test, named plasma microbial cell-free DNA sequencing (mcfDNA-Seq), detected infection-causing pathogens days before standard blood cultures, offering a potential approach to protecting vulnerable patients by allowing treatment to start before the patient gets sick. The study is published in The Lancet Microbe.

Bloodstream infections are a major threat to children undergoing treatment for leukemia. Chemotherapy weakens the immune system, making even common bacteria or fungi potentially life-threatening. These infections can quickly lead to sepsis, prolonged hospital stays, delayed chemotherapy and, in some cases, early mortality. Catching these infections early is critical, yet clinicians currently have no reliable method to identify infections before symptoms appear.

“We’re not good at predicting or preventing infections in children with cancer, and the consequences can be deadly, causing lasting damage or delaying chemotherapy, which reduces the chances of successful treatment,” said first and corresponding author Joshua Wolf, Ph.D., MBBS, St. Jude Department of Infectious Diseases. “Many infections still happen even with the best prevention strategies we have, so what we really need is a way to detect infections before they start, so we can treat kids earlier and save lives.”