ISLAMABAD, May 8 (Xinhua) -- Four environmental samples in Pakistan have tested positive for wild poliovirus type 1, the country's National Institute of Health (NIH) said on Wednesday.
The virus has been detected in four more sewage samples taken from two cities in the country, raising the tally of this year's environmental samples to 112, the regional reference laboratory for polio eradication at the NIH said in a statement.
Three samples were collected from the southern port city of Karachi whereas one was found in the Pishin district of the country's southwest Balochistan province, the statement said.
The samples were genetically linked to the imported YB3A cluster of WPV1, the statement said, adding that the virus has been found in sewage samples of 33 districts of the country this year so far.
All positive samples and the two human cases reported this year contain YB3A cluster, and it is a threat to every child, particularly children below five years old, who could get a lifelong physical disability from it, the statement added.
The country's health ministry said in an earlier statement that an integrated strategy has been formulated in high-risk areas of polio, and the parents must get the polio vaccine administered to their children during every polio immunization campaign to defeat the disease in the country. ■