Surveillance Systems to Track Progress Toward Polio Eradication - Worldwide, 2015-2016

Area of Science:

• Public Health
• Virology
• Epidemiology

Background:

• Global polio eradication initiatives have made significant progress, with four of six WHO regions certified polio-free by 2014.
• Wild poliovirus (WPV) transmission persists in Nigeria, Afghanistan, and Pakistan within the African and Eastern Mediterranean regions.
• Surveillance for acute flaccid paralysis (AFP) and environmental sampling are key methods for detecting poliovirus, including vaccine-derived polioviruses (VDPVs).

Purpose of the Study:

• To present poliovirus surveillance data for 2015-2016.
• To assess surveillance quality in 20 African and six Eastern Mediterranean countries reporting WPV or circulating VDPVs (cVDPVs).
• To identify surveillance gaps and areas for improvement to achieve polio eradication.

Main Methods:

• Analysis of acute flaccid paralysis (AFP) surveillance data, including nonpolio AFP rates and stool adequacy.
• Review of environmental surveillance data for polioviruses.
• Genomic sequencing of poliovirus isolates to map transmission and identify VDPVs.

Main Results:

• In 2016, 60% of African Region countries and 100% of Eastern Mediterranean Region countries met national surveillance quality indicators.
• Provincial-level variations in surveillance quality were observed.
• Countries affected by the Ebola outbreak were also included in the surveillance assessment.

Conclusions:

• While national surveillance indicators show progress, provincial-level disparities require attention.
• Strengthening surveillance activities, including supervision and specimen handling, is essential for polio eradication.
• Identifying and addressing surveillance gaps are critical next steps for completing global polio eradication.