Progress Toward Poliomyelitis Eradication - Pakistan, January 2018-September 2019.

Area of Science:

• Public Health
• Epidemiology
• Infectious Disease Control

Background:

• Afghanistan and Pakistan remain the only countries with ongoing wild poliovirus type 1 (WPV1) transmission.
• Pakistan experienced a notable increase in WPV1 cases in 2018 and a further surge by November 2019 compared to previous years.
• Environmental surveillance indicated a rise in WPV1-positive sites, suggesting wider circulation.

Purpose of the Study:

• To update on Pakistan's polio eradication activities, progress, and persistent challenges.
• To analyze the factors contributing to the resurgence of WPV1 in Pakistan.
• To identify necessary changes for achieving polio eradication goals.

Main Methods:

• Review of WPV1 case data from January 2018 to September 2019.
• Analysis of environmental surveillance data from sewage sampling.
• Assessment of supplementary immunization activities (SIAs) and their effectiveness in core reservoirs and non-reservoir areas.

Main Results:

• WPV1 cases in Pakistan increased by 50% in 2018 (12 cases) compared to 2017 (8 cases).
• By November 7, 2019, 80 WPV1 cases were reported, a significant rise from 8 cases during the same period in 2018.
• Intensified SIAs failed to interrupt WPV1 transmission in core areas and prevent resurgence in other regions, with WPV1 detected in sewage samples from multiple districts.

Conclusions:

• Challenges including vaccine refusals, missed children, campaign fatigue, and poor implementation hinder polio eradication efforts.
• Substantial program modifications are required to address vaccination gaps and improve campaign quality.
• Enhanced cross-border coordination, community trust-building, and improved managerial processes are essential for attaining national and global polio eradication.