Tracking progress toward global polio eradication--worldwide, 2009-2010.

Since the Global Polio Eradication Initiative (GPEI) began in 1988, progress has been tracked by 1) surveillance comprised of detection and investigation of cases of acute flaccid paralysis (AFP), coupled with environmental surveillance (sewage testing) in selected areas, and 2) timely testing of fecal specimens in accredited laboratories to identify polioviruses. The sensitivity of AFP case detection and the timeliness of AFP investigations are monitored with performance indicators. Polioviruses are isolated and characterized by the Global Polio Laboratory Network (GPLN). This report assesses the quality of polio surveillance and the timeliness of poliovirus isolation reporting and characterization worldwide during 2009--2010. During that period, 77% of countries affected by wild poliovirus (WPV) met national performance standards for AFP surveillance; underperforming subnational areas were identified in two of four countries with reestablished WPV transmission and in 13 of 22 countries with WPV outbreaks. Targets for timely GPLN reporting of poliovirus isolation results were met in five World Health Organization (WHO) regions in 2009 and in four of six regions in 2010; targets for timely poliovirus characterization were met in four WHO regions in 2009 and in five regions in 2010. Monitoring of surveillance performance indicators at subnational levels continues to be critical to identifying surveillance gaps that might allow WPV circulation to be missed in certain areas or subpopulations. To achieve polio eradication, efforts are needed to further strengthen AFP surveillance, implement targeted environmental surveillance, and ensure that GPLN quality is maintained.