Surveillance To Track Progress Toward Poliomyelitis Eradication — Worldwide, 2021–2022

Abstract

This report provides an update on the surveillance performance during 2021-2022 in 34 priority countries for poliovirus transmission. The report describes that by the end of 2022, wild poliovirus type 1 (WPV1) transmission remained endemic only in Afghanistan and Pakistan, while WPV serotypes 2 and 3 have been declared eradicated. However, Malawi and Mozambique reported 9 WPV1 cases that were genetically linked to cases in Pakistan, and outbreaks due to circulating vaccine-derived poliovirus (cVDPV) were detected in 42 countries. The report highlights that high-quality surveillance is critical to rapid detection of poliovirus transmission and prompt poliovirus outbreak response to stop circulation. In 2022, 26 (76.5%) priority countries met the 2 AFP surveillance performance indicator targets nationally, as compared with 24 (70.6%) countries in 2021; however, substantial gaps remain in subnational areas. Environmental surveillance was extended to 725 sites in priority countries, a 31.1% increase over the 553 sites reported in 2021. The report concludes that frequent monitoring of surveillance indicates where improvements are required to progress towards polio eradication.