Impact of the Syrian conflict on vector-borne disease trends in Syria and neighboring countries: A one health ProMED analysis between 2003 to 2018

Abstract

Background: Syria's uprising which escalated into conflict in 2011 has displaced half of the pre-war population of 22 million with most of the 5 million Syrian refugees residing in Turkey, Lebanon, Jordan and Iraq. The aim of this study is to analyze ProMED reports from the region with the aim of understanding the impact of conflict on vector-borne disease (VBD) trends among both humans and animals. ProMED is a digital, global outbreak reporting system that uses formal and informal sources to rapidly publish reports on emerging infectious diseases. Methods and materials: The ProMED search engine was queried for outbreak events occurring in Syria and surrounding countries (Turkey, Lebanon, Jordan, Iraq) between 2003–2018. The latter countries were selected as the main Syrian-refugee hosting countries. Posts were deduplicated and the most recent posting was saved. Suspected and confirmed case counts, species affected, and date of event were manually extracted. Posts included human and animal sources. VBD events were defined using WHO, OIE, and NIAID criteria. Results: 743/1961 (38%) of initial reports were retained, and 125/743 (17%) of all events were due to a VBD. The number of VBD events began increasing annually in 2011 and reached its peak in 2017. A comparison between the eight years before the Syrian Conflict and eight years after its onset revealed an increase in VBD events from an average of 2.9/year to 12.8/year, reflecting a 343% increase (p < 0.05). The three most common VBD during the Syrian Conflict were leishmaniasis (62%), Lumpy Skin Disease, and Crimean-Congo hemorrhagic fever. On a country level, Syria (32), Iraq (30), and Turkey (27) showed the highest numbers of VBD events. Conclusion: This study finds that VBD events increased in Syria and surrounding countries after the onset of the Syrian conflict. This is likely due to the disruption of vector-control mechanisms, the destruction of health and sanitation infrastructure in Syria and the strains on these infrastructures in neighboring countries. These trends support increased attention to vector-control health measures during conflict as well as ongoing, enhanced disease surveillance.