Surveillance to Track Progress Toward Polio Eradication - Worldwide, 2016-2017

Area of Science:

• Public Health
• Infectious Disease Epidemiology
• Virology

Background:

• Polio eradication efforts have achieved significant success, with four WHO regions certified polio-free.
• Wild poliovirus (WPV) transmission persists in Afghanistan, Nigeria, and Pakistan within the African and Eastern Mediterranean Regions.
• Surveillance for acute flaccid paralysis (AFP) and environmental sampling are key methods for detecting poliovirus circulation.

Purpose of the Study:

• To present poliovirus surveillance data from 2016-2017 in the African Region (AFR) and Eastern Mediterranean Region (EMR).
• To assess the status of WPV and circulating VDPV (cVDPV) detection and surveillance quality in focus countries.
• To identify areas needing surveillance strengthening for polio eradication.

Main Methods:

• Analysis of poliovirus surveillance data, including acute flaccid paralysis (AFP) surveillance and environmental surveillance.
• Genomic sequencing of isolated polioviruses to map transmission patterns.
• Evaluation of national-level surveillance quality indicators in 20 AFR and six EMR countries.

Main Results:

• In 2017, 70% of 20 AFR countries and 83% of six EMR countries met national surveillance quality indicators.
• Provincial-level variations in surveillance quality were observed.
• WPV or cVDPV transmission was reported in specific countries within these regions during 2011-2017.

Conclusions:

• Surveillance quality varies, with notable provincial-level differences.
• Targeted surveillance strengthening activities are essential in specific countries.
• Enhanced surveillance is critical to support the final certification of polio eradication.