How Early Warning, Alert, and Response Systems Save Lives in Emergencies

When disaster strikes, whether from natural calamities, armed conflicts, or disease outbreaks, health systems often crumble just when they’re needed most. People displaced from their homes crowd into temporary shelters with limited access to clean water and healthcare. In these vulnerable moments, infectious diseases can spread rapidly, turning a crisis into a catastrophe. This is where Early Warning, Alert, and Response Systems step in to save lives.

What makes EWAR systems critical during emergencies 🔗

Early Warning, Alert, and Response Systems, commonly known as EWAR, function as the frontline defense against disease outbreaks during humanitarian crises. These systems are designed to detect disease outbreaks quickly before they spread, allowing health authorities to respond immediately.

The primary goal is straightforward: reduce preventable illness and death caused by epidemic-prone diseases during emergencies. EWAR was first implemented in South Sudan in 1999 after a relapsing fever outbreak response was delayed by six months, resulting in over 2,000 deaths. This tragedy underscored the urgent need for rapid disease detection systems in crisis situations.

During emergencies, routine public health surveillance systems often become disrupted, underperforming, or completely non-functional. EWAR fills this critical gap by providing a temporary surveillance mechanism that can be deployed rapidly, sometimes within 48 hours of an emergency declaration.

How EWAR systems work in the field 🔗

EWAR operates through a structured three-phase approach. The early warning phase involves continuous data collection from health facilities and community sources. Health workers use simple case definitions adapted for each emergency situation, reporting cases through mobile phones or other available communication channels.

The alert component automatically triggers when predefined thresholds are exceeded. For example, a single case of cholera, measles, or yellow fever may indicate an outbreak requiring immediate investigation. These alerts generate immediate notifications via SMS or email to rapid response teams.

The response phase activates public health measures based on confirmed alerts. This includes outbreak investigation, laboratory confirmation when possible, targeted interventions like vaccination campaigns, and continuous monitoring of disease trends.

EWARS in a box: bringing surveillance to remote areas 🔗

EWARS in a box contains essential equipment to establish surveillance activities in difficult field settings without reliable electricity or internet. The kit includes 60 mobile phones, laptops, a local server, solar generators, and solar chargers. A single kit costs approximately $15,000 and can support surveillance for 50 clinics serving roughly 500,000 people.

Diseases and threats monitored by EWAR 🔗

EWAR systems focus on epidemic-prone communicable diseases that pose immediate threats to displaced and affected populations. The specific diseases monitored vary based on the context and epidemiological risk profile of each emergency.

Priority diseases requiring immediate action 🔗

Certain diseases demand immediate response due to their rapid transmission potential. EWAR systems have successfully detected major outbreaks including polio reemergence in Syria and Somalia in 2013, hepatitis E in South Sudan, and measles in Iraq. Cholera outbreaks represent another critical threat, particularly in settings with compromised water and sanitation systems.

Watery diarrhea, bloody diarrhea, acute respiratory infections, and meningitis are monitored through syndromic surveillance. Laboratory confirmation may be delayed or unavailable in emergency settings, so health workers rely on simplified case definitions to identify potential cases quickly.

Zoonotic diseases and environmental hazards 🔗

EWAR systems also monitor zoonotic diseases that can jump from animals to humans. Population displacement often brings people into closer contact with livestock or wildlife, increasing exposure risk. Environmental hazards like chemical contamination from damaged infrastructure may also be tracked depending on the emergency context.

The system maintains flexibility to adapt to emerging threats. When unusual disease patterns or unexplained clusters of illness appear, EWAR protocols trigger investigation even if the condition wasn’t originally on the priority list.

Navigating challenges in emergency settings 🔗

Implementing EWAR during humanitarian crises presents unique obstacles that differ significantly from routine surveillance in stable environments.

Infrastructure disruption and access limitations 🔗

Natural disasters and armed conflicts destroy health facilities, communication networks, and transportation infrastructure. In conflict zones, insecurity may prevent surveillance staff from reaching affected populations or limit their ability to conduct outbreak investigations. During Syria’s crisis, surveillance teams operated remotely from Turkey due to security concerns, coordinating field activities through innovative use of available technology.

Power outages and lack of internet connectivity complicate data transmission. This is why EWARS in a box includes solar equipment and offline data collection capabilities, allowing surveillance to continue even in areas without electricity or communication networks.

Overwhelmed healthcare systems 🔗

Emergency situations strain even robust health systems. Health facilities become overwhelmed with patients, staff shortages worsen, and medical supplies run low. Adding surveillance activities to already burdened healthcare workers requires careful planning and simplified data collection processes.

EWAR addresses this by focusing on a limited number of priority diseases and reducing reporting frequency to weekly rather than daily, except for immediate alert conditions. This minimizes the burden on healthcare workers while maintaining effective outbreak detection.

Displaced populations and mobile communities 🔗

Tracking disease patterns becomes challenging when populations are constantly moving. People fleeing conflict or disaster may cross international borders, settle temporarily in one location before moving again, or disperse across multiple camps and settlements. This mobility makes it difficult to establish accurate denominators for calculating disease rates and to follow up on suspected cases.

Community-based surveillance helps address this gap by training community health workers and volunteers to identify and report unusual health events. This extends the surveillance network beyond health facilities into camps and settlements where displaced people live.

Laboratory capacity constraints 🔗

Confirming suspected cases through laboratory testing is often impossible during the acute phase of emergencies. Laboratory facilities may be destroyed, specimens cannot be safely transported, or testing reagents are unavailable. EWAR compensates by using syndromic case definitions that allow for immediate action based on clinical symptoms rather than waiting for laboratory confirmation.

Coordination among multiple partners 🔗

Humanitarian responses typically involve numerous organizations including government health authorities, United Nations agencies, international NGOs, and local community groups. Establishing a unified surveillance system that all partners contribute to requires extensive coordination and agreement on reporting formats, case definitions, and communication channels.

Success stories demonstrating EWAR impact 🔗

Real-world implementations demonstrate EWAR’s effectiveness in preventing large-scale outbreaks. Following Pakistan’s devastating 2010 floods affecting 18 million people, rapid expansion of the Disease Early Warning System helped identify disease trends early. Proactive preparedness activities prevented a major cholera outbreak despite widespread water contamination.

After Haiti’s 2010 earthquake displaced roughly 2 million people, the Internally Displaced Persons Surveillance System monitored communicable diseases across camps. The system provided critical epidemiological data from areas where no other health information would have been available.

In Somalia, faster outbreak response in urban areas using EWARS showed dramatic improvement. Response delays dropped from two months in 2008 to just 14-19 days in 2016 and 2018, demonstrating how established systems strengthen over time.

Looking ahead: strengthening emergency preparedness 🔗

EWAR represents a temporary measure designed to bridge gaps until routine surveillance systems recover. As emergencies transition to recovery phases, EWAR functions should be reintegrated into national surveillance systems rather than operating as permanent parallel structures.

Countries prone to disasters and conflict benefit from preparing EWAR protocols and training staff before emergencies occur. This pre-emergency preparedness allows for rapid system activation when crises strike, saving precious time during the critical early response period.

Ongoing development of standardized training materials, evaluation tools, and remote support protocols continues to improve EWAR effectiveness. As technology advances, systems can leverage mobile applications, automated alert generation, and real-time data visualization to enhance early detection and response capabilities.

What do you think? How might improved early warning systems have changed the course of recent health emergencies you’ve heard about? What role should technology play in expanding surveillance to remote and conflict-affected areas?

References

1. https://www.who.int/emergencies/surveillance/early-warning-alert-and-response-system-ewars
2. https://wwwnc.cdc.gov/eid/article/23/13/17-0446_article
3. https://emergency.unhcr.org/emergency-assistance/health-and-nutrition/disease-surveillance-thresholds
4. https://www.paho.org/en/health-emergencies/health-emergency-information-and-risk-assessment/early-warning-alert-and