Nine samples return positive for poliovirus across Pakistan

• Four cases tested positive in Karachi, two in Chaman. 
• One case detected from Peshawar, Kohat, Nowshera. 
• Number of positive environmental samples rise to 64.

KARACHI: About nine environmental samples, collected from five cities including Karachi in October, have tested positive for poliovirus, raising the current year's tally in Pakistan to 64, The News reported Friday. 

According to the National Institute of Health (NIH) Islamabad, the detection of Type-1 Wild Poliovirus (WPV1) was confirmed in four samples from Karachi, two from Chaman, and one each from Peshawar, Kohat and Nowshera. 

Poliovirus was detected in two environmental samples from Karachi South including Manzoor Colony Nala and Hijrat Colony sites, and Sohrab Goth and Machar Colony Environmental sites in Karachi East, officials said. They said the poliovirus found in Karachi South from Manzoor Colony Nala is classified as a YB3A cluster and 99.66% genetically linked to the virus detected in an environmental sample in Karachi East Gadap on September 12. 

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

The poliovirus found in the environmental sample in the Sohrab Goth in Karachi East is classified as a YB3A cluster and 99.89% genetically linked to the virus detected in an environmental sample in the same district (i.e. Karachi East) on September 12. Similarly, the poliovirus found in the environmental sample in Machar Colony in District East Karachi is classified as a YB3A cluster and 99.77% genetically linked to the virus detected in an environmental sample in the same district (ie Karachi East) on October 6, 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 district this year. The previous two positive samples were collected on October 2 (n = 2). The isolated virus is classified as a YB3A cluster and 99.89% genetically linked to the virus detected in an environmental sample in the same district (ie 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 District Chaman this year. The previous three positive samples were collected on October 2 (n = 2) and October 16. The isolated virus is classified as a YB3A cluster and 99.55% genetically linked to the virus detected in an environmental sample in the same district (ie Chaman - Hadi Packet) on October 2, they added.

In Peshawar, the environmental sample (Grab) was collected on October 23 from the "Shaheen Town" environmental sample collection site. This is the 20th positive sample from district Peshawar this year. The previous nineteen positive samples were collected on 10th April, 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 isolated virus in Peshawar is classified as a YB3A cluster and 99.22% genetically linked to the virus detected in an environmental sample in District Hangu on September 6.

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

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

These new detections take the total number of positive environmental (sewage) samples in Pakistan in 2023 to 64. Meanwhile, the number of human Polio cases in Pakistan in 2023 remains four.