ISLAMABAD: The presence of wild poliovirus has been confirmed in Lahore after sewage samples collected from different areas tested positive, according to health officials.

The virus detection was confirmed by the World Health Organisation (WHO) Regional Reference Laboratory at the National Institute of Health. The sample was collected from the Multan Road area.

Three of the four samples from the city have been genetically linked to a virus cluster in Afghanistan.

An official of the health ministry said if the poliovirus is found in sewage water, the sample is called “positive”.

Minister says increased testing resulting in more WPV1 detections

“Sewage samples are a basic parameter to determine the success of polio campaigns. Moreover, the presence of viruses in sewage also shows that the immunity level of children in the area has fallen and they are at risk of catching the disease,” he said.

This is the fourth wild poliovirus or WPV1 detection in Lahore this year. The city last reported a case of poliovirus in July 2020.

A polio vaccination campaign is ongoing in the city which will conclude on September 10.

Federal Health Minister Dr Nadeem Jan has called the development “concerning” but added that Pakistan Polio Programme (PPP) has vastly expanded its poliovirus surveillance system.

“Today, we are testing more than double the number of samples we tested last year. So, these detections highlight the strength of the system to be able to detect the virus,” the minister said in a statement.

According to a health official, the PPP is already testing for poliovirus at 114 fixed environmental sites every month.

For enhanced surveillance in high-risk areas, additional sewage samples were being collected from multiple sites periodically, the official added.

“We are also testing environmental samples collected from Afghanistan and Yemen.”

According to data, the Polio Laboratory tested over 1,700 samples in 2023. Of these, 22, or nearly one per cent, were positive for the presence of WPV1.

The detection of the virus in Lahore came four days after four environmental samples collected from Karachi and Peshawar tested positive for WPV1.

In 2023 so far, two children have been paralysed by polio. Both cases were reported from Bannu, which is among the seven districts in southern Khyber Pakhtunkhwa that remain polio-endemic.

Federal Secretary Health Iftikhar Shallwani has said the ministry’s top priority was the eradication of the crippling disease.“Polio eradication is not just an objective, it is the topmost priority for the ministry. Every child deserves a life free from the threat of polio, and we are dedicated to making this a reality,” Mr Shallwani said.

Published in Dawn, September 10th, 2023