Nine samples come back positive for polio virus across Pakistan

• Four cases tested positive in Karachi, two in Chaman.
• One case was identified from Peshawar, Kohat, Nowshera.
• The number of positive environmental samples is 64.

KARACHI: As many as nine environmental samples, collected from five cities including Karachi in October, have tested positive for the polio virus, taking this year’s toll in Pakistan to 64. The news reported on Friday.

According to the National Institute of Health (NIH) Islamabad, detection of wild polio virus type 1 (WPV1) was confirmed in four samples from Karachi, two from Chaman and one each from Peshawar, Kohat and Nowshera.

The polio virus was detected in two environmental samples from south Karachi, including Manzoor Colony Nala and Hijrat Colony sites and Sohrab Goth and Machar Colony environmental sites in Karachi East, officials said. They said the polio virus found in South Karachi from Manzoor Nala Colony has been classified as YB3A complex and is 99.66% genetically related to the virus found in an environmental sample in Karachi East Gadap on September 12.

Similarly, the poliovirus found in the environmental sample at Hijrat Colony is classified as YB3A complex and is 99.33% genetically related to the virus detected in an environmental sample in Lahore (Out Fall station-2) on 15 August 2023.

The polio virus found in the environmental sample at Sohrab Goth in Karachi East has been classified as YB3A cluster and is 99.89% genetically related to the virus detected in an environmental sample in the same area (i.e. Karachi East) on 12 September. Similarly, the polio virus found in the environmental sample in Machar Colony in Karachi East District is classified as YB3A cluster and is 99.77% genetically related to the virus detected in an environmental sample in the same area (i.e. Karachi East) on 6 October 2023.

In Chaman, an environmental sample was collected on October 16 from the “Hadi Packet” environmental sample collection site, officials said, adding that this is the third positive sample from the area this year. The two previous positive samples were collected on 2 October (n = 2). The isolated virus is classified as YB3A complex and is 99.89% genetically related to the virus detected in an environmental sample in the same area (i.e. Chaman – Hadi Packet) on October 2, 2023, they added.

Another environmental sample (Grab) was collected on October 16 from the ‘Army Kaziba’ environmental sample collection site in Chaman, which is the fourth positive sample from Chaman district this year. The previous three positive samples were collected on 2 October (n = 2) and 16 October. The isolated virus is classified as YB3A complex and is 99.55% genetically related to the virus detected in an environmental sample in the same area (ie Chaman – Hadi Packet) on October 2, they added.

In Peshawar, the environmental sample (Grab) was collected on 23 October from the ‘Shaheen Town’ environmental sample collection site. This is the 20th positive sample from Peshawar district this year. The previous nineteen positive samples were collected on April 10, May 9, May 16, June 5, July 4, July 17, August 1, August 17, August 22 (n = 2), September 5, September 12, September 20 (n = 2), October 4 (n = 2) and October 5 (n = 3). The virus isolated in Peshawar is classified as YB3A cluster and is 99.22% genetically related to the virus detected in an environmental sample in Hangu District on 6 September.

In Kohat, the environmental sample (Grab) was collected on October 20 from environmental sample collection point “Faqeerabad”, officials said adding that this is the first positive sample from Kohat District this year. The virus isolated in Kohat is classified as YB3A cluster and is 98.67% genetically related to the virus detected in an environmental sample in Batikot, Nangarhar (Afghanistan) on 1 March.

At Nowshera, the environmental sample (Grab) was collected on 24 October from the environmental sample collection site “Mill Colony”. This is the first positive sample from Nowshera district this year. The isolated virus is classified as YB3A complex and is 99.55% genetically related to the virus detected in an environmental sample in Lahore (Multan Road) on 26 September.

These new detections bring the total number of positive environmental (wastewater) samples in Pakistan in 2023 to 64. Meanwhile, the number of human polio cases in Pakistan in 2023 remains at four.