Poliovirus found again in Pishin, two Karachi districts

ISLAMABAD: The regional reference laboratory for polio eradication at the National Institute of Health Islamabad has confirmed the detection of Type-1 wild poliovirus (WPV1) from four environmental surveillance (ES) samples, including one each from Pishin in Balochistan and Malir Karachi, as well as two samples collected from Karachi East.

In Pishin, the environmental sample was collected on April 1, 2024, from the ‘Turwa’ environmental sample collection site. This marks the second positive sample from District Pishin this year. The previous positive sample from the district was collected on January 2, 2024. Officials stated that the isolated virus is classified as a YB3A cluster and is genetically linked to the virus detected in an environmental sample in Chaman on January 2, 2024, with a 99.66% match.

In Karachi’s Malir district, the environmental sample was collected on April 16, 2024, from the ‘Landhi Bakhtawar Village’ environmental sample collection site. This marks the fourth positive sample from District Karachi Malir this year. The previous three positive samples were collected on January 15, February 12, and March 11, 2024. The isolated virus is classified as a YB3A cluster and is genetically linked to the virus detected in an environmental sample in Karachi Central on February 15, 2024, with a 99.89% match.

In Karachi’s East district, the 14th positive sample was collected on April 16, 2024, from the ‘Machar Colony’ environmental sample collection site. The previous 13 positive samples were collected on January 8, January 9, January 10, January 11, February 20 (n = 2), February 21 (n = 3), March 7, March 13 (n = 2), and March 14, 2024. The isolated virus is classified as a YB3A cluster and is genetically linked to the virus detected in an environmental sample in Karachi Keamari on March 4, 2024, with a 99.66% match.

The 15th positive sample from Karachi East was collected on April 17, 2024, from the ‘Sohrab Goth environmental sample collection site. The isolated virus is classified as a YB3A cluster and is genetically linked to the virus detected in an environmental sample in the same district, Karachi East, on March 14, 2024, with a 99.44% match.

So far, poliovirus has been found in 112 environmental samples across 33 districts in the first four months of 2024, compared to 126 samples from 28 districts in the entire year of 2023.