Islamabad [Pakistan], April 22 (ANI): Two additional sewage samples, this time from Quetta and Karachi, have tested positive for the presence of wild poliovirus type 1 (WPV1), sparking concern among health officials, Dawn reported. According to Regional Reference Lab for Polio Eradication at the National Institute of Health, these samples were genetically linked to the imported YB3A cluster of the virus, which is prevalent in Afghanistan. Despite the successful eradication of the cluster from Pakistan in 2021, its continued circulation in the neighbouring country has led to its reintroduction …