ISLAMABAD: The pre­sence of poliovirus has been confirmed in seven distri­cts across all four provinces.

The Regional Refer­ence Laboratory for Polio Era­dication at the National Institute of Health (NIH) tested sewage samples from nine districts, of which seven were found positive for the presence of poliovirus.

A sewage sample from an area is the basic parameter used to identify the presence of the virus in an area.

It determines if polio vaccination campaigns were resulting in the desired immunity among children.

An NIH official said wild poliovirus type 1 (WPV1) was detected in sewage samples collected from Gwadar, Quetta, South Waziristan Lower, South Waziristan Upper, Rawalpindi, Larkana and Mirpurkhas.

The two negative samples were collected from Pishin and Lahore.

The official explained that if the virus is found in sewage, it is called a positive sample and whenever a child is paralysed with the virus, it is called a positive case.

After the virus is detected in sewage samples, polio campaigns are held in the area to eradicate the virus, the official said.

Published in Dawn, June 22nd, 2025