A review of the performance of the early warning alert and response system (EWARS) in conflict-affected Borno State, Nigeria: a five-year descriptive analysis.

BACKGROUND

The northeastern region of Nigeria has been experiencing a protracted humanitarian crisis, characterized by conflict, displacement, and a severely disrupted health system. The Early Warning Alert and Response System (EWARS) was implemented in 2016 to strengthen disease surveillance in this challenging context.

METHODS

This study employed a descriptive design to evaluate the performance of EWARS in Borno State, Nigeria, over a five-year period (2016-2021). The data sources included weekly health facility reports and the EWARS alert log. Key performance indicators, including timeliness and completeness of reporting, were analyzed.

RESULTS

EWARS coverage expanded significantly, reaching 341 health facilities across 25 local government areas. The timeliness of reporting ranged from 6 to 85%, with a median of 65.5% (95% CI: 59-73%). A statistically significant positive Pearson correlation was observed between timeliness and the duration of implementation (r = 0.45, p < 0.001). Completeness of reporting ranged from 42 to 96%, with a median of 68% (95% CI: 62.0-76.25%) and a weaker but significant positive correlation (r = 0.19, p < 0.001). A total of 13,737 alerts were generated, of which 89.6% were verified within 24 hours. However, only 0.1% required an immediate public health response. While systematically recorded data on response activities were limited, verified alerts-particularly for measles and cholera-reportedly triggered vaccination campaigns, case investigations, and WASH interventions.

CONCLUSIONS

The EWARS system demonstrated significant operational value in strengthening disease surveillance and triggering early warning alerts in the conflict-affected Borno State. Despite not meeting all national performance targets, the system showed improvements over time and supported early detection and verification of potential outbreaks. Its utility as a first-line surveillance tool is evident, though future efforts should prioritize integrating response documentation and event-based surveillance components to strengthen public health impact assessment.