Skip to content

Download PDF

Introduction

1. What is EWAR?

  • EWAR stands for "Early Warning, Alert and Response".
  • It is one of the most immediate and important functions of surveillance.

2. What is the objective of EWAR?

The objective of EWAR is to support the early detection and rapid response to acute public health events of any origin.

3. EWAR and Health Security

  • The 2005 International Health Regulations state that countries must strengthen their frontline capacity to detect, assess, notify, and report events involving disease or death above expected levels for the particular time and place in all areas of the country.

  • The EWAR function of the surveillance system forms the backbone for achieving this core capacity.

  • EWAR emphasizes direct links between communities and all levels of the health system to achieve early detection and response to outbreaks and other public health emergencies.

4. What do we mean by an emergency?

  • The WHO's Emergency Response Framework (ERF) states that WHO country offices must establish or strengthen EWAR within 7 to 14 days after the onset of an emergency being declared.

An emergency may include one or more of the following:

  • Complex humanitarian emergencies (situations of war or civil strife affecting large civilian populations with food shortages and population displacement)
  • Natural disasters (e.g. floods, tsunamis, earthquakes)
  • Food insecurity and famine
  • Large-scale disease outbreaks that overwhelm national capacity
  • Food contamination, chemical or radio-nuclear spills, and public health emergencies due to other hazards

5. Why is EWAR important in emergencies?

One of the most urgent priorities in an emergency is to establish a functioning EWAR system to rapidly detect and respond to outbreaks.

  • In emergencies, the existing national surveillance systems may be underperforming, disrupted or non-existent.

  • Emergencies also create risk factors for the transmission of communicable diseases which can result in high levels of excess morbidity and mortality.

6. What are the main components of an EWAR system?

  • EWAR can be most easily understood as a system composed of three core components.

Basic

  • In this guidance, each of these components is broken down and described in more detail.
Component Description
Early Warning Early warning refers to the organised processes to collect and report data from a range of different sources, in order to trigger potential alerts to public health events.

These sources of early warning data are categorised as indicator-based surveillance and event-based surveillance.
Alert Alert refers to the systematic process of verification and risk assessment of acute public health alerts to initiate a rapid response where needed.

Regardless of the source of the information, all alerts should be managed according to a standardised workflow.
Response Response refers to any public health action that is initiated based on the verification and risk assessment of alerts.

This guidance focuses on role of EWAR in strengthening surveillance duting the response to acute public health events.

Detailed