Pakistani health authorities have detected four more polio cases in the country, posing a major challenge to the nation which has so far failed to eradicate the disease.

According to reports, authorities detected wild poliovirus type-1 in three children from Balochistan and one child from Khyber Pakhtunkhwa.

Following the detection of the four instances, the total number of polio cases detected this year in the country now stands at 37.

The children affected by the wild poliovirus include a girl from Pishin, two boys from Chaman and Noshki in Balochistan, and a girl from Lakki Marwat district of KP, according to an official of the regional reference laboratory for polio eradication as quoted by Dawn News.

Of the 37 cases detected from across Pakistan so far this year, the official said, 20 have been reported from Balochis­tan, 10 from Sindh, five from KP, and one each from Punjab and Islamabad.

“Genetic sequencing of the cases is underway,” he disclosed.

“These were the first polio cases from Noshki and Lakki Marwat this year,” he told Dawn News, adding that both Chaman and Pishin had reported one poliovirus case each earlier as well.

Pakistan will launch a nationwide polio campaign on Oct 28 to vaccinate 45 million children under the age of five against paralytic polio.