After the UK discovered poliovirus in sewage samples in London for the first time in the last four decades, suspicion has fallen on Pakistan as being the source, the media reported.
However, health authorities in Islamabad claim the "vaccine-derived virus" found in the UK exists in 22 countries and the type found locally was the wild poliovirus (WPV), reports Dawn news. The UK Health Security Agency noted that the virus was probably imported from some country, and has asked parents to ensure their children were fully immunised against the crippling disease.
Pakistan Polio Eradication Programme National Coordinator, Shahzad Baig said that it was too early to say the virus had travelled from Pakistan, as UK authorities were yet to announce the results of genome sequencing, Dawn reported. Genome sequencing helps determine the origin of a virus, as samples detected in different areas have a different ribonucleic acid (RNA). A number of times, cases reported in Pakistan were reported to have originated from the neighbouring Afghanistan during genome sequencing.
"We are waiting for the genetic sampling report of the virus. Moreover, there are two types of polioviruses in the world: WPV that is present in Pakistan and Afghanistan, and the vaccine-derived poliovirus (VDPV). The environmental samples in London were found to be of the VDPV, which exists in 22 countries, so Pakistan should not be blamed for exporting it before getting the report of genetic sequencing," Baig stressed.
He said the vaccine-derived variety could have travelled from Nigeria, Egypt, Pakistan, Afghanistan, Yemen, Sudan, Central Africa and a number of other countries. Nadeem Jan, a public health expert said Pakistan will be in a difficult, rather embarrassing, situation if it was proved that the virus found in London travelled from the South Asian country.
"Pakistan has been already under a travel advisory due to which every person has to get vaccinated and carry a vaccination certificate before travelling abroad. We also claim that over 90 per cent vaccination target has been achieved. The world may doubt our claims if it is found that the virus belongs to Pakistan," Dawn quoted Jan as saying. Shahzad Baig, while replying to a question, claimed the poliovirus was generally in control in Pakistan, except North Waziristan where there were refusals towards the vaccine and people were not cooperating with polio teams.