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Kolkata: Despite the complexities of poliovirus that make it difficult to stop from spreading, an expert on Thursday said that the disease is “gasping” and is on the verge of eradication from the global map.
Heaping praise on India for playing an exemplary role in effectively dealing with polio, researcher Dr Ananda Sankar Bandyopadhyay sounded caution that any complacency could help the disease make a comeback.
Bandyopadhyay, who is the Deputy Director of Technology, Research, and Analytics, Polio Team, with the Bill and Melinda Gates Foundation, was speaking exclusively to PTI on the occasion of World Polio Day on Thursday.
“Polio has three serotypes -- type 1, type 2 and type 3. Type 2 and 3 were eradicated from the world. Poliovirus type 1 remains mainly in two countries - Pakistan and Afghanistan. So, about the global situation, we can say that polio is on the verge of eradication," he said.
Besides Pakistan and Afghanistan, there are about 15 countries primarily in the African region where an outbreak of a variant poliovirus type was seen recently, he said.
“So, it's really good news that polio does not exist in most of the countries,” Bandyopadhyay said.
The researcher also praised India saying the country has done a commendable job in eradicating polio.
"The fact that India can maintain its polio-free status is really an amazing feat and we should be proud of that and celebrate that. It has huge implications in terms of other public health delivery programmes," Bandyopadhyay said.
Asked whether it is possible to permanently eradicate polio from the world, the expert said, "From a scientific perspective, polio as a virus is gasping. In Pakistan and Afghanistan exists the wild type poliovirus whereas in a few countries in the African region, the variant poliovirus type exists.
“Based on this, you can say that eradication is feasible because most countries have decisively stopped polio but of course, challenges remain.” Explaining the problems in eradicating the disease completely, he said that in certain countries it is difficult to vaccinate all the children all the time.
“These are areas affected by wars, civil unrest, and insurgencies in parts of these countries. So the children are unfortunately vulnerable and are not receiving the vaccination that they deserve,” said the expert who had earlier worked with the World Health Organisation (WHO).
If all children of all communities can be inoculated in these countries, the spread of polio could be stopped decisively, he said.
About the reasons behind the resurgence of polio in Gaza almost after a quarter of a century, the expert said, "There is one single reason: children in places like Gaza unfortunately have no access to vaccination. On top of that, they do not have access to clean drinking water. Sanitation system and hygienic practices were also disrupted due to the war.” Besides polio, other life-threatening diseases could also emerge because of the situation there, Bandyopadhyay said.
On whether polio could reappear at a place where it was once eradicated, he said that resurgence is possible in case of a dip in the vaccination coverage and relaxation of surveillance on the disease.
Asked if polio, like coronavirus, has any chance of emerging in a different form, of which the world is unaware at the moment, the WHO researcher said that the genetic structure of the poliovirus tends to revert to evolve in newer strains.
“Yes… there is a risk that newer subfamilies of the poliovirus could evolve and we have seen that in different areas, although the overall serotype of polio remains intact,” he said on World Polio Day.
World Polio Day is observed on October 24 every year to emphasise efforts taken around the world to eradicate Polio alongside raising awareness of the importance of vaccination to protect every child from this life-threatening disease.