Predictors of severe leptospirosis: a review.

objectiveLeptospirosis is a zoonosis of global importance with a wide array of clinical outcomes. The clinical course of leptospirosis varies from an undifferentiated mild febrile illness to multiorgan dysfunction and death. Severe leptospirosis requires input from multiple specialties and management in the intensive care setting. Predicting severe disease manifestations early during the course of illness helps to triage patients to appropriate treatment settings, which greatly improves the outcome.

methodsA narrative literature search was conducted by searching for relevant articles including cohort studies, experimental studies, case-control studies and cross-sectional analyses published on leptospirosis disease severity.

resultsStudies have identified clinical parameters such as dyspnoea, oliguria, hypotension and icterus in isolation or in combination to be useful in predicting severe disease manifestations of leptospirosis. In addition, laboratory (haematological and biochemical) parameters, immunological, vascular endothelium-related markers and selected microRNAs have been identified as potential markers of severe disease in leptospirosis. Even though none of the markers are validated as severity predictors to date, patient characteristics such as age, haematological and biochemical parameters are potential predictors of severe leptospirosis that could be utilised in resource poor settings.

conclusionA wide array of clinical parameters and laboratory markers have been identified in literature as potential predictors of severe leptospirosis. Validation of these markers in appropriate settings would lead to the development of severity prediction models in the future.