ISLAMABAD [Pakistan], The presence of wild poliovirus type 1 (WPV1) has been confirmed in sewage samples collected from two districts of Balochistan and one district of Sindh in Pakistan, Dawn reported, according to the National Institutes of Health. Sewage samples taken from Quetta, Chaman and Hyderabad have tested positive for WPV1. These samples contained a virus genetically related to the imported YB3A genetic cluster of WPV1. This particular cluster disappeared from Pakistan in 2021, but remained prevalent in neighboring Afghanistan, after it was reintroduced into Pakistan through cross-border transmission last year. All positive samples and the two polio cases reported this year are linked to this virus. Overall WPV1 has been detected. According to Dawn, the Pakistan Polio Program has conducted four polio vaccination campaigns across 38 districts so far this year, including two nationwide campaigns that reached more than 43 million children under five years of age in January and February . Who is the next vaccination drive scheduled for? In Hyderabad, samples were collected from Tulsidas Pumping Station in the first week of June. Interestingly, five previous samples from this site had also tested positive. Chaman's sample was obtained from the Army Kajiba site, which is the ninth positive sample from the district this year. According to Dawn report, a source at the National Institute of Health revealed that in Quetta, the th sample was collected from the railway bridge site, which is the eighteenth positive sample from the Quetta district this year.