Electronic Surveillance System for the Early Notification of Community-Based Epidemics (ESSENCE): Overview, Components, and Public Health Applications (Preprint)

Abstract

BACKGROUND The Electronic Surveillance System for the Early Notification of Community-Based Epidemics (ESSENCE) is a secure web-based tool that enables health care practitioners to monitor health indicators of public health importance for detection and tracking of disease outbreaks, consequences of severe weather, and other events of concern. The ESSENCE concept began in an internally funded project at the Johns Hopkins University Applied Physics Laboratory (JHU/APL), advanced with funding from the State of Maryland, and broadened in 1999 as a collaboration with the Walter Reed Army Institute for Research. Versions of the system have been further developed by JHU/APL in multiple military and civilian programs for timely detection and tracking of health threats. OBJECTIVE Aims of this article are to describe the components and development of a biosurveillance system increasingly coordinating all-hazards health surveillance as well as infectious disease monitoring among large and small health departments, to list key features and lessons learned in the growth of this system, and to describe the range of initiatives and accomplishments of local epidemiologists using it. METHODS Features of ESSENCE include spatial and temporal statistical alerting, custom querying, user-defined alert notifications, geographical mapping, remote data capture, and event communications. For visualization, configurable and interactive modes of data stratification and filtering, graphical and tabular customization, user preference management, and sharing features allow users to query data and view geographic representations, time series and data details pages, and reports. These features allow ESSENCE users to gather and organize the resulting wealth of information into a coherent view of population health status and communicate findings among users. RESULTS The resulting broad utility, applicability and adaptability of this system led to adoption of ESSENCE by the Centers for Disease Control and Prevention (CDC), numerous state and local health departments, and the Department of Defense (DOD) both nationally and globally. An open-source version SAGES is available for global, resource-limited settings. Resourceful users of the US NSSP ESSENCE have applied it to surveillance of infectious diseases, severe weather and natural disaster events, mass gatherings, chronic diseases and mental health, and injury and substance abuse. CONCLUSIONS With emerging high-consequence communicable diseases and other health conditions, the continued user-requirements-driven enhancements of ESSENCE demonstrate an adaptable disease surveillance capability focused on the everyday needs of public health. The challenge of a live system for widely distributed users with multiple different data sources and high throughput requirements has driven an novel, evolving architecture design.