I now have comprehensive, authoritative information from WHO, PAHO, UNHCR, ECDC, and peer-reviewed sources to write a thorough explanation of EWARS. Here it is:
EWARS - Early Warning, Alert and Response System
1. Definition and Background
EWARS (Early Warning, Alert and Response System) is a WHO-developed digital surveillance system designed to rapidly detect disease outbreaks in emergency and humanitarian settings - such as conflict zones, post-disaster areas, and refugee camps - and trigger an immediate public health response.
It was born out of a tragic lesson: in
South Sudan in 1999, a 6-month delay in detecting a relapsing fever outbreak led to
more than 2,000 deaths. This event catalyzed the development of a systematic early warning mechanism for emergencies. EWARS has since been deployed in over
31 countries, including Sudan, Syria, Yemen, South Sudan, Somalia, Haiti, Colombia, and Nigeria. -
PMC5711309
The overall aim of EWARS is to reduce excess morbidity and mortality due to epidemic-prone diseases and other public health hazards in emergency-affected populations.
2. What is EWAR vs EWARS vs EWARN?
These are related but distinct concepts:
| Term | Full Form | Meaning |
|---|
| EWAR | Early Warning, Alert and Response | The general concept/process of detecting and responding to health signals |
| EWARS | Early Warning, Alert and Response System | WHO's specific software and technology platform that operationalizes EWAR |
| EWARN | Early Warning, Alert and Response Network | A network of health partners that collectively implements EWAR in a region (used in WHO EMRO countries like Syria, Iraq, Afghanistan) |
3. Core Objective
"To support the early detection and rapid response to acute public health events of any origin." - PAHO/WHO
Specifically, EWARS aims to:
- Detect outbreaks before they spread and claim lives
- Provide a simple, cost-effective surveillance infrastructure where none exists
- Work in settings with no reliable internet or electricity
- Connect field health workers to decision-makers in real time
- Generate automated epidemiological reports to inform response
4. Three Core Components of EWAR
According to the UNHCR/WHO operational framework, EWAR has three interconnected components:
A. Early Warning (Signal Detection)
- The rapid detection of signals that may indicate a potential acute public health event.
- Uses two complementary surveillance approaches:
| Type | Description |
|---|
| IBS (Indicator-Based Surveillance) | Structured, routine reporting from health facilities using standardized case definitions and counts (e.g., weekly disease tallies) |
| EBS (Event-Based Surveillance) | Unstructured reports from any source - community members, rumors, media, health workers - that something unusual is happening. Can be implemented faster than IBS at emergency onset |
- Alert thresholds are pre-set for each disease. When a threshold is crossed, the system automatically flags the event for urgent investigation.
B. Alert (Verification and Triage)
- Upon receiving a signal, the system activates an immediate investigation to verify whether the event represents a true outbreak threat.
- Verification typically occurs within 24 hours of alert generation.
- Alerts are triaged as: Discarded (false alarm), Monitored (watch and see), or Requires Response (confirmed outbreak).
In Nigeria's Borno State (2015-2020), of 13,737 alerts generated: 89.6% were verified within 24 hours; 20.3% required monitoring; only 0.1% required a full response. -
PMC12482565
C. Response (Action)
- Once an alert is verified as a real event, EWARS supports rapid public health response including:
- Outbreak investigation (case-based line listing with GPS coordinates)
- Generic immediate control measures
- Agent-specific control measures (e.g., vaccination, case isolation, water chlorination)
- Real-time epidemic curves, maps, and dashboards
- Automated daily outbreak bulletins shared with partners
5. EWARS Technology Platform
EWARS is made up of 3 key software components:
i. EWARS Mobile (Data Collection)
- A mobile app installed on smartphones distributed to health workers at reporting sites (clinics, health posts)
- Workers submit weekly aggregate reports and immediate case alerts using pre-configured digital forms
- Works offline - data queues and submits when network is available
- Provides SMS feedback to facilities: report receipt confirmations, overdue reminders, and instant alert notifications
ii. EWARS DataHub (Server/Analysis)
- A local server that receives, stores, and processes all incoming data
- Generates automated epidemiological bulletins, epidemic curves, and maps
- Works fully offline - no internet required
- Allows customized analysis, line-list export, and anonymization of data for partner sharing
- Hosts alert threshold logic and sends alert notifications
iii. EWARS Exchange (Online Dashboard)
- An online platform for when internet connectivity is available
- Allows broader data sharing with national authorities, WHO, and partner organizations
- Supports integration with national surveillance systems
6. EWARS "in a Box"
"EWARS in a box" is a pre-packaged, ready-to-deploy physical kit developed by WHO containing all hardware and software needed to establish surveillance in the field.
Contents of the Box:
- 60 mobile phones (for data collection at health facilities)
- Laptops (for data management and analysis)
- A local server (DataHub - works offline)
- Solar generator and solar chargers (for areas without electricity)
- Network equipment and accessories
- Pre-loaded surveillance software
Key Specifications:
| Feature | Detail |
|---|
| Cost | ~US$ 15,000 per kit |
| Coverage | 50 fixed or mobile clinics; ~500,000 people |
| Deployment time | Can be configured within 48 hours of emergency declaration |
| Electricity | Not required (solar powered) |
| Internet | Not required (offline-capable) |
| Mobile network | Required (for SMS alerts) |
7. Diseases and Conditions Monitored
EWARS uses syndromic case definitions because laboratory confirmation is often unavailable in emergency settings. Priority diseases typically monitored include:
| Category | Examples |
|---|
| Vaccine-preventable | Measles, yellow fever, acute flaccid paralysis (polio indicator) |
| Diarrheal diseases | Acute watery diarrhea (cholera indicator), bloody diarrhea |
| Vector-borne | Malaria, dengue |
| Respiratory | Acute respiratory infections, meningitis |
| Hemorrhagic fevers | Viral hemorrhagic fever |
| Others | Severe acute malnutrition, neonatal tetanus, relapsing fever |
In conflict-affected Borno State, Nigeria, the most frequent alert triggers were
measles (44.3%), malaria (22.2%), acute flaccid paralysis (7.8%), and acute watery diarrhea (6.7%). -
PMC12482565
8. EWARS Alert Threshold System
Each disease has a pre-defined alert threshold - a numerical trigger based on case counts or rates. When the threshold is crossed:
- The system automatically generates an alert
- Alert is sent via SMS to surveillance officers
- A 24-hour verification is initiated
- If confirmed, a public health response is activated
Thresholds can be simple (e.g., 1 case of acute flaccid paralysis = immediate alert) or complex algorithmic rules depending on disease severity and epidemic potential.
9. EWARS Implementation Process
EMERGENCY DECLARED
↓
Rapid needs assessment (existing surveillance capacity?)
↓
Configure EWARS (diseases, thresholds, reporting sites, case definitions)
↓
Deploy EWARS in a Box → Train health workers
↓
Weekly aggregate reporting + Immediate case alerts
↓
Automated alert generation → 24h verification
↓
Response activation (investigation, control measures)
↓
Weekly epidemiological bulletins → Feedback to facilities
↓
Post-emergency: Re-integrate into national surveillance system
10. Governance and Partners
- EWARS is led and managed by WHO in coordination with:
- Ministries of Health (national ownership)
- UNHCR (refugee settings)
- UNICEF, MSF, NGOs (health facility network)
- US CDC (technical support and evaluation)
- ECDC (European contexts)
Local health workers are trained by WHO to use and maintain the system. After the emergency phase ends, EWARS is designed to re-integrate back into the national surveillance system.
11. EWARS vs Routine Surveillance Systems
| Feature | EWARS | Routine National Surveillance |
|---|
| Setting | Emergencies, conflicts, disasters | Stable, peacetime settings |
| Deployment | Within 48 hours | Years to develop |
| Electricity needed | No (solar) | Yes |
| Internet needed | No (offline) | Usually yes |
| Case definitions | Syndromic (clinical) | Often lab-confirmed |
| Purpose | Outbreak detection + response | Trend monitoring + policy |
| Data flow | Mobile → DataHub → Exchange | Facility → District → National |
12. Where EWARS Has Been Used
EWARS and EWARN have been implemented in: Sudan/Darfur (2004 - first deployment), South Sudan, Syria, Iraq, Yemen, Somalia, Afghanistan, Libya, Nigeria (Borno State), Haiti (post-earthquake), Colombia (floods), Mauritania, and many others.
Summary
EWARS is WHO's answer to a critical gap in global health security - the breakdown of disease surveillance in humanitarian crises. By packaging simple, offline-capable technology into a portable kit that can be deployed within 48 hours, EWARS enables health workers in the most challenging environments to detect outbreaks early, alert the right people quickly, and respond before diseases spiral into epidemics. It is a practical bridge between the chaos of emergencies and the structured response needed to save lives.