Mass General's EvalMpox Tool Helps Clinicians Spot Mpox Cases and Safely Rule Them Out

Across more than 100 clinical locations in Greater Boston, on Nantucket and Martha's Vineyard, in western Massachusetts and in southern New Hampshire, clinicians saw patients who walked in with a rash. Mpox was one possible explanation, but it is an uncommon disease, and few clinicians have much experience spotting it. A group at Massachusetts General Hospital built a tool meant to close that gap.

The tool is called EvalMpox. It is a clinical decision support system embedded in the electronic medical record. Rather than leaving a clinician to remember what to look for, it walks them through it: questions about possible mpox exposures, questions about symptoms, and a physical examination aimed at the characteristic mpox rash. Once the answers are entered, EvalMpox sorts the patient into one of two groups, "likely to have mpox" or "unlikely to have mpox."

The researchers, from Mass General, a founding member of the Mass General Brigham system, tested the tool across 668 patient visits. Their findings appear in Infection Control and Healthcare Epidemiology. Jacob Lazarus, MD, PhD, the lead author, is a physician investigator in the Division of Infectious Diseases in Mass General's Department of Medicine and an instructor in Medicine at Harvard Medical School. He described the project as a decision support tool built into the record that guides clinicians on key physical exam features and the important questions to ask when mpox is possible.

The patients the tool judged likely to have mpox resembled, in their characteristics, the patients who were confirmed to have the disease. Those flagged patients were prioritized for testing, and they were significantly more likely to test positive than the patients judged unlikely to have it.

The senior author, Erica S. Shenoy, MD, PhD, is Chief of Infection Control for Mass General Brigham and an associate professor of Medicine at Harvard Medical School. She said the program identified nearly all of the mpox cases diagnosed in the system during the study period. In her view, that underscores what decision support can add to early identification, isolation and management of patients with communicable diseases such as mpox. Early isolation matters because it reduces spread.

The tool also showed a high negative predictive value. In practice, when EvalMpox called a patient low risk, that person was very unlikely to have the infection. Shenoy stressed that this half of the result matters too. Early identification and isolation to prevent transmission cannot be overemphasized, she said, but it is just as important to have efficient ways to decide when isolation can end, and to reassure patients that they probably do not have an infection.

The team sees the approach reaching beyond mpox. Lazarus said that, drawing on lessons from the COVID-19 pandemic and the mpox outbreak, they are developing decision support tools for other emerging infections, including Ebola, Lassa fever and Marburg virus disease. They are also working on tools for more routine infections that affect how care is delivered because they require patient isolation. The next thing to watch is whether those tools perform as EvalMpox did.