Pakistan polio program categorizes districts into four distinct risk categories—endemic/core reservoir, outbreak, risk reduction, and maintenance—based on the risk present, allowing for the implementation of appropriate risk-based activities.

Endemic Districts:  South KP, comprising 7 districts, is classified as endemic.

Core Reservoirs: 13 districts of Karachi, Peshawar, Khyber, and the Quetta block are considered core reservoirs. These areas are defined as contiguous geographic zones with persistent local WPV1 circulation for at least 12 months and a history of repeatedly reseeding the virus outside the immediate transmission zones.

Outbreak Districts:  Districts with recent detections of the poliovirus, either from human cases or environmental samples, are classified as outbreak districts.

Risk Reduction:  High consequence districts based on risk assessment. These are vulnerable districts adjacent to outbreak or infected areas.

Maintenance Districts:  All other districts fall under this category.