Progress and peril: poliomyelitis eradication efforts in Pakistan, 1994-2013.

Area of Science:

• Epidemiology
• Infectious Diseases
• Public Health

Background:

• Pakistan remains one of three countries with ongoing wild poliovirus (WPV) transmission.
• Despite a >90% decline in cases, outbreaks persisted from 2008-2013, primarily WPV type 1.
• The majority of WPV cases (81%) during 2012-2013 occurred in Federally Administered Tribal Areas (FATA) and Khyber Pakhtunkhwa due to conflict and security issues.

Purpose of the Study:

• To analyze the epidemiology of wild poliovirus (WPV) and circulating vaccine-derived poliovirus type 2 (cVDPV2) in Pakistan.
• To identify key challenges and high-risk areas for polio transmission.
• To inform strategies for polio eradication in Pakistan.

Main Methods:

• Retrospective analysis of WPV and cVDPV2 case data from 2012-2013.
• Geographic mapping of cases, focusing on conflict-affected regions.
• Review of factors hindering supplementary immunization activities (SIAs).

Main Results:

• WPV cases (151) were predominantly WPV type 1, concentrated in FATA and Khyber Pakhtunkhwa.
• 350,000 children in FATA missed polio vaccination due to bans since mid-2012.
• 62 cVDPV2 cases were detected, with 65% in FATA during 2013.
• Attacks on polio workers disrupted SIAs in other areas since mid-2012.

Conclusions:

• Conflict, security issues, vaccination bans, and attacks on health workers severely impede polio eradication in Pakistan.
• Reaching unvaccinated children in FATA and other compromised areas is critical to prevent WPV resurgence and global spread.