Cholera Outbreak in Yemen: Timeliness of Reporting and Response in the National Electronic Disease Early Warning System.

Introduction: In Yemen, the largest cholera epidemic of modern times started in late 2016. By March 2018, more than one million cases had been reported. A national electronic Disease Early Warning System (eDEWS) for infectious disease surveillance was established in 2013.

Aim: This study assessed the eDEWS's timelines for reported cholera cases.

Methods: Quantitative data published in eDEWS and the Weekly Epidemiological Bulletin of the Yemen Ministry of Health from March 2013 until March 2018 were analyzed. For assessing the early detection of cholera cases, 262 weekly bulletins were reviewed. The raw data of the immediately generated eDEWS alerts during the first outbreak wave were used to assess response timeliness.

Results: Reported cholera incidence peaked at 1,698 cases (first wave) in 2016 week 49, and then reached 46,667 cases (second wave) in 2017 week 26. The mean time period between reporting and the first response was 2.85 days. Only 31% of the eDEWS alerts were verified within the first 24 hours, and the majority (83%) were verified within one week. There were major differences in the timeliness between the governorates, ranging from 8%-62% for reporting within the first 24 hours.

Conclusion: The eDEWS is able to detect and alert health authorities about cholera cases even under conditions of ongoing war and civil war, however, the timeliness of the response needs improvement.