The polio-virus vanished in most parts of the country in recent tests of the sewage samples, sources said. The virus has not been detected in tests of sewage samples taken from across the country. The extensive environmental surveillance established by the Pakistan Polio Eradication Programme collects sewage water samples to detect the polio-virus across the country. In all four provinces, sewage water samples were found free from the polio-virus in recent tests, sources said. The sewage samples were collected from 08 to 23 April this year from more than 60 places across the country and tested. Sewage water samples were gathered from Machhar Colony and Khameeso Goth in Karachi and Sukkur apart from Islamabad, Rawalpindi, Multan, D.G. Khan for tests, according to sources. The polio-virus was not confirmed in sewage water samples gathered from Lahore and Faisalabad. The virus was also not detected from the sewage samples collected from Quetta, Qilla Abdullah and Loralai in Balochistan. Sewage samples of Peshawar, Charsadda, Mardan, Nowshera and Bannu were also found free from the polio-virus. According to sources after the first wave of the coronavirus in the country, the situation with regard to polio cases has improved. After the first wave of the Covid-19 an effective anti-polio campaign was launched across the country, sources said.