Pakistan’s efforts to combat polio encounter a new obstacle as the National Polio Laboratory at the National Institute of Health in Islamabad has verified the presence of Type-1 Wild Poliovirus (WPV1) in four sewage samples, with one of these samples originating from Karachi testing positive.
On August 17, a sewage sample collected from the Muhammad Khan Colony environmental collection site in Karachi’s Keamari area was found to contain the wild poliovirus. This marks the second positive sample in Karachi this year.
The isolated virus belongs to the YB3A cluster and shares a genetic similarity of 99% with the virus discovered in an environmental sample in Nangarhar-Batikot, Afghanistan, on March 1, 2023.
This development follows a recent polio vaccination campaign conducted in the district from August 7 to August 13. Including this case, Pakistan has now recorded a total of 21 positive environmental (sewage) samples in 2023.
In the current year, there have been two reported cases of poliovirus in Pakistan, one on February 20 and another on July 11 in Bannu.
The other three positive samples were collected from Peshawar’s Shaheen Muslim Town, Yousafabad, Tajabad, and Hayatabad 1 and 2 tributaries. These constitute the tenth positive samples identified in the district this year.
All these isolated viruses are part of the YB3A cluster and are genetically connected to the virus detected in a polio case in Behsud, Afghanistan, on May 16, 2023.
Despite the recent polio vaccination campaign (fIPV+OPV) conducted in Peshawar from August 7 to August 13, the continued detection of polio in environmental samples raises concerns about the challenges faced by health authorities in the region.