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Doctor at Rhode Island Hospital Develops Ebola Virus Diagnostic Tool
Adam C. Levine, MD, an emergency medicine physician at Rhode Island Hospital who treated Ebola-infected patients in Liberia last year, has used his field experience to create a tool to determine the likelihood that patients presenting with Ebola symptoms will actually carry the virus. His research was published online April 3 in the Annals of Emergency Medicine.
Ebola virus disease (EVD) has affected 24,000 persons during the current epidemic, which is the largest recorded outbreak of EVD in history. More than 10,000 people have died in West Africa, mainly in Sierra Leone, Liberia, and Guinea.
Because the initial symptoms are not specific to EVD, diagnosing the disease remains a significant challenge. This is the first time that researchers scientifically derived a clinical prediction model, the Ebola Prediction Score, for patients with suspected EVD who await laboratory confirmation.
“There is a lag time between a suspected case and a confirmation,” Levine said. “The Ebola Prediction Score will help clinicians risk-stratify patients already meeting one or more suspect definitions of EVD.”
Typical predictors for EVD include fever, nausea/vomiting, diarrhea, fatigue, abdominal pain, loss of appetite, muscle pain, joint pain, headache, difficulty breathing, difficulty swallowing, hiccups, unexplained bleeding, and exposure to a suspected or confirmed EVD patient within 21 days. In Levine’s Ebola Prediction Score tool, six of those symptoms — contact with a sick person, diarrhea, loss of appetite, muscle pain, difficulty swallowing, and the absence of abdominal pain –– create the model. A scoring system based on these signs may help clinicians determine who is most likely to require isolation while laboratory tests confirm the diagnosis.
“Admitting a patient who is unlikely to have EVD to an ETU [emergency tactical unit] in a rural setting or to a community-based isolation center puts that patient at risk for exposure,” Levine said. “Determining which patients to admit for definitive testing and treatment required balancing the epidemiologic imperative to break the train of transmission in the community against the ethical imperative to ‘do no harm’ to each individual patient, all within the context of severe resource constraints.”
Patient data were collected during routine clinical care at the 52-bed Bong County ETU in Liberia during its first 16 weeks of operation. EVD test results were available for 382 of the 395 patients admitted to the ETU during the study period. A total of 160 patients (42%) tested positive for EVD.
According to Levine, while the Ebola Prediction Score can help determine who is more likely to have EVD and treat them accordingly, better testing needs to be a focus. “Given the inherent limitations of clinical prediction models, a low-cost, point-of-care test that can rapidly and definitively exclude EVD in patients should be a research priority,” he said.
Sources: Rhode Island Hospital; April 3, 2015; and Annals of Emergency Medicine; April 3, 2015.