Polio threat rises in Pakistan as virus found widely

Poliovirus is spreading in Pakistan. Samples from 18 districts show the virus. This means a polio outbreak threat exists. Tests found the virus in sewage. The National Institute of Health confirmed this. Samples were collected in April. They came from many areas. The virus was found in major cities. These include Karachi, Lahore, and Quetta. Other districts also tested positive.