Epidemiological Analysis of Acute Flaccid Paralysis (AFP) Surveillance in Conflict-Affected Syria

Abstract

Syria has been polio-free since 1999; however, due to factors including mass displacement, insecurity, and the decreasing functionality of public health infrastructure, poliomyelitis (polio) reemerged in 2013-2014 and 2017. The aims of this study were to describe trends in the incidence and surveillance of the clinical diagnosis of polio, acute flaccid paralysis (AFP), in northern Syria over a three-year period during the ongoing conflict. We conducted a retrospective analysis of reported AFP incidence and surveillance among AFP cases in people under the age of 15 years from January 2018 to December 2020. We utilized data collected from the Early Warning Alert and Response Network (EWARN) operated by the Assistance Coordination Unit (ACU). A total of 1124 cases of AFP were reported in northern Syria during the study period. More than half of the children were under five years of age (n= 837, 68.9%) and 57.7% (n= 701) were male. All cases were classified as non-polio cases based on serology, with one case classified as polio compatible. Surveillance indicators were constantly above the minimum targets on a national level, with a significant increase in the adequacy of stool specimens and rank of reporter over the period studied. AFP surveillance data are the final measure of a country's progress towards polio eradication. While the ACU has strengthened the sensitivity and quality of the AFP surveillance system in northern Syria over time, additional efforts are needed to strengthen subnational sensitivity.