Poliovirus detected in KP, Sindh sewage samples

ISLAMABAD: Pakistan’s National Polio Laboratory at the National Institute of Health (NIH) Islamabad on Saturday confirmed the detection of Wild Poliovirus Type-1 (WPV1) as well as Vaccine Derived Poliovirus Type 3 (VDPV3) from the environmental samples collected from Dera Ismail Khan in Khyber Pakhtunkhwa and Ghotki district of Sindh respectively.

Giving the details of Wild Poliovirus Type-1 (WPV1) detection from the environmental sample collected from Dera Ismail Khan in Khyber Pakhtunkhwa, an official of the NIH Islamabad said the environmental (sewage) sample was collected on 21st February 2023 from the Paroa environmental sample collection site.

This is the first positive environmental (sewage) sample from the endemic zone of South KP this year, and the third positive environmental (sewage) sample from Pakistan at large in 2023. “It is worth mentioning here that no human Polio case has been reported from District DI Khan since December 2019. The new positive environmental (sewage) sample is genetically linked to the poliovirus detected in the same district (i.e. DI Khan) in November 2022. The last polio vaccination campaign in the district was conducted on 13 — 17 February 2023”, the official added.

As far as the detection of Vaccine Derived Poliovirus Type-3 (VDPV3) from the environmental sample collected from district Ghotki is concerned, the NIH official informed The News that the environmental (sewage) sample was collected on 14th February 2023 from the Bago Wah environmental sample collection site.

This is the first detection of the Vaccine Derived Poliovirus Type-3 (VDPV3) in the country this year, with 11 nucleotides difference from the reference sabin strain. The last polio vaccination campaign in the district was conducted on 16 — 20 January 2023”, the official added.

The NIH official maintained that polio eradication teams in both districts in support and guidance from the National and Provincial EOCs were working to respond to the detections. “The Program has already planned a Polio vaccination campaign in Mid-March in Punjab, Sindh & Islamabad and in the first week of April in Khyber Pakhtunkhwa and Balochistan wherein bivalent Oral Polio Vaccine will be used which is very effective against both types of Polioviruses”, the NIH official added.

On the other hand, the Global Commission for the Certification of Poliomyelitis Eradication (GCC) which met recently in Amman, Jordan, to review progress towards interrupting wild poliovirus type 1 (WPV1) transmission in polio-endemic Pakistan and Afghanistan, raised concerns over shortcomings in surveillance performance, particularly the timeliness of detection and quality of environmental surveillance in some localities.

The Commission reiterated the importance of environmental surveillance as a supplement to AFP surveillance, and while recognizing that its utility varies depending on ground realities, recommended that further analysis be conducted into ES system performance and for updates to be provided to the group on a biannual basis.