ISLAMABAD, July 13 (Xinhua) -- Wild poliovirus type 1 has been detected in sewage samples from 11 sites across Pakistan, health authorities said on Sunday.

A total of 24 sewage samples were tested in June. Of these, 13 were found negative, while 11 samples confirmed the presence of poliovirus.

Authorities attributed the declining virus circulation to improved surveillance and high-quality vaccination campaigns nationwide.

As part of the ongoing eradication efforts, special immunization drives will be conducted from July 14 to July 18 in parts of the northwestern Khyber Pakhtunkhwa province and the northern Gilgit-Baltistan region, targeting more than 150,000 children. A follow-up campaign will also be carried out in Islamabad and its twin city Rawalpindi, aiming to vaccinate over 160,000 children.

Pakistan remains one of only two countries in the world where wild poliovirus remains endemic. ■