Evaluation of acute flaccid paralysis surveillance performance before and during the 2014-2015 Ebola virus disease outbreak in Guinea and Liberia.

Introduction: the number of wild poliomyelitis cases, worldwide, dropped from 350,000 cases in 1988 to 33 in 2018. Acute flaccid paralysis (AFP) surveillance is a key strategy toward achieving global polio eradication. The 2014 Ebola virus disease (EVD) epidemic in West Africa infected over 28,000 people and had devastating effects on health systems in Guinea, Liberia, and Sierra Leone. We sought to assess the effects of the 2014 Ebola outbreak on AFP surveillance in Guinea and Liberia.

Methods: a retrospective cross-sectional analysis was performed for Guinea and Liberia to evaluate EVD´s impact on World Health Organization (WHO) AFP surveillance performance indicators during 2012-2015.

Results: both Guinea and Liberia met the WHO target non-polio AFP incidence rate nationally, and generally sub-nationally, prior to the EVD outbreak; rates decreased substantially during the outbreak in seven of eight regions in Guinea and 11 of 15 counties in Liberia. Throughout the study period, both Guinea and Liberia attained appropriate overall targets nationally for "notification" and "stool adequacy" indicators, but each country experienced periods of poor regional/county-specific indicator performance.

Conclusion: these findings mirrored the negative effect of the Ebola outbreak on polio elimination activities in both countries and highlights the need to reinforce this surveillance system during times of crisis.