965. Applying Clinical Prediction Tools to Patients with Lassa Fever

Abstract

Background. Clinical prediction tools such as the Quick Sequential Organ Failure Assessment (qSOFA) and the Modified Early Warning Score (MEWS) have been used to predict mortality from sepsis in high-income countries, but their application to low-and middle-income countries have been limited. Lassa fever is a viral hemorrhagic fever endemic to West Africa with a case fatality ratio for hospitalized patients of up to 69%. The purpose of this study was to evaluate existing clinical prediction tools for critical illness in predicting adverse outcomes in patients with Lassa fever. Methods. We conducted a retrospective cohort study of patients admitted to the Kenema Government Hospital Lassa ward in Sierra Leone between 2012 and 2017. Patients were required to meet the World Health Organization case definition for suspected Lassa Fever to be admitted to the ward. We included patients who had laboratory-confirmed Lassa fever via ELISA tests for Lassa Ag or IgM. Control samples were included with negative ELISA tests for Lassa Ag and IgM. We compared criteria for qSOFA, MEWS, Systemic Inflammatory Response Syndrome (SIRS), and Universal Vital Assessment (UVA) among the Lassa Ag+ (patients with acute viremia), Ag-/IgM+ (patients who cleared the virus and developed an immune response), and Ag-/IgM-(control) groups. Results. There were 157 patients included in this preliminary analysis. Of patients in the Ag+ group, the mean age was 20.2 years and 40.8% were female. Patient demographics were similar among all groups. Clinical outcomes significantly differed among the groups, with the highest in-hospital mortality at 62.5% in the Ag+ group. For each clinical prediction tool, mean scores significantly differed among groups (P < 0.05; see table). The highest scores were consistently seen in the Ag+ group. Conclusion. Patients with acute viremia for Lassa fever had higher scores for clinical prediction tools compared with controls, which imply a higher risk of mortality. Additional research is needed on the sensitivity and specificity of these tools for mortality due to Lassa fever. (Table Presented).