The polio virus has been found in sewerage samples taken from at least 10 different cities of the country in different months of the on-going year, The Nation learnt on Wednesday.

The samples were taken from Multan, Peshawar, Rawalpindi, Lahore, Faisalabad, Jacobabad, Sukkur, Karachi, Quetta, Killa Abdullah and Dera Ismail Khan under Environment Surveillance programme of Pakistan Polio Eradication Initiative, sources disclosed.

"Four areas are working as major reservoirs of polio virus and it moves to other areas of the country when people from these areas move to other parts of the country," sources confided to this scribe.

The areas include Federally Administered Tribal Areas (FATA), the Quetta block (Killa Abdullah) in Balochistan, some parts of Khyber Pakhtunkhwa province and the Gadap, Baldia and Gulshan-e-Iqbal areas of Karachi.

Sources disclosed that over 70 percent of total polio cases reported from the country were reported from these reservoir areas while the majority of wild viruses reported from cases in other areas were also genetically linked to those of these reservoir areas. Polio experts believe that the harvesting season is the major time when the virus carriers take it to others areas as labourers and nomads move to different parts of the country during this time of the year to earn their living.

After 306 polio cases reported in 2014, the Polio Eradication Programme in Pakistan has made a major breakthrough as just 38 cases have so far been reported from across the country till filing of this report in 2015.

Sources claimed that a sudden surge in the number of cases in 2014 forced the country to revisit its polio eradication strategy. "The strategy was redesigned, micro planning was done and efforts were made to cover maximum population, especially nomads to block the spread of polio. It delivered considerably," sources added.

Giving details of areas where virus was found in environmental samples, sources disclosed that it was traced in four samples in Multan between January and October 2015. "We have four collection sites - Ali Town, Head Naubahar, Sooraj Miani and Kotla Abdul Fatah in Multan. The virus was found in Sooraj Miani sample in April, Kotla July and Ali Town and Kotla August," sources further revealed. "This virus has a genetic link with that of Jacobabad and Quetta," Sources added.

There are two collection sites in Rawalpindi and one Islamabad and occasionally virus is traced from the samples taken from Pir Wadahi site in Rawalpindi. In Lahore, the virus is found on Bund Road collection site, out of three sites as Pakhtun community is living in this area.

Similarly, there are two sample collection sites in Peshawar and virus is found at both sites continuously while the samples taken from DI Khan also contained virus, which had a genetic link with Killa Abdullah and Quetta.

Referring to Sindh, the sources disclosed that the virus was found from samples taken from Jacobabad/Sukkur and this virus had come from Karachi in 2014. Similarly, the samples taken from Hyderabad and Karachi also contained virus. In Balochistan, samples were taken from Quetta and Killa Abdullah which contained polio virus.

"Kashmir and Gilgit Baltistan are polio free areas while the samples taken from Faisalabad have also turned out to be virus free," sources revealed.