Pakistan’s National Polio Laboratory at the National Institute of Health (NIH) in Islamabad has confirmed the discovery of Wild Poliovirus Type-1 (WPV1) and Vaccine-Derived Poliovirus Type 3 (VDPV3) in environmental samples collected from Dera Ismail Khan in Khyber Pakhtunkhwa and the Ghotki district of Sindh.
According to the study, a Dera Ismail Khan environmental sample that was analyzed included WPV1. A National Institutes of Health (NIH) representative disclosed that the sample was collected on February 21 at the Paroa environmental sample collecting site.
This is the first positive sewage sample from the Southern KP endemic zone obtained in 2023.
It is vital to mention that no human polio cases have been reported in District DI Khan since December 2019. However, the new environmental sample (sewage) is genetically linked to the poliovirus identified in the same area (i.e., in November 2022). (DI Khan). The last polio vaccine program for the district occurred between February 13 and 17, 2023, according to the official.
On the other hand, the Ghotki district environmental sample revealed the presence of VDPV3. According to the NIH representative, the environmental sample (sewage) was collected at the Bago Wah environmental sample collecting location on February 14.
This is the first identification of VDPV3 in the country this year, with 11 nucleotides distinct from the reference sabin strain. According to the official, the district’s most recent polio vaccine program occurred between January 16 and 20.
The NIH representative emphasized that the National and Provincial EOCs directed and supported the polio eradication teams in both districts as they responded to the detections.
“The program has already scheduled a Polio vaccination campaign for mid-March in Punjab, Sindh, and Islamabad, and for the first week of April in Khyber Pakhtunkhwa and Balochistan, during which bivalent oral polio vaccine (which is highly effective against both types of polioviruses) will be administered,” the NIH official explained.
On the other hand, the Global Commission for the Certification of Poliomyelitis Eradication (GCC), which recently met in Jordan to review progress towards halting WPV1 transmission in Pakistan and Afghanistan, expressed concern regarding the efficacy of surveillance, particularly the promptness of detection and the quality of environmental surveillance in some localities.
The commission emphasized the value of environmental surveillance as a supplement to acute flaccid paralysis (AFP) surveillance and, while recognizing that its applicability depends on local conditions, recommended that additional research be conducted on the performance of ES systems and that the group receive updates every two years.
 and Vaccine-Derived Poliovirus Type 3 (VDPV3) in environmental samples collected from Dera Ismail Khan in Khyber Pakhtunkhwa and the Ghotki district of Sindh.){kind=link}