Is Discovery Of Poliovirus In Kolkata Cause For Worry?

Now in shocking news, polio virus was found in a sewage in Kolkata's Metiabruz area. However, experts said that it wasn't a cause for concern.

You all must have seen many people having polio - poliomyelitis. Every 3 months, the governments have a polio vaccination drive. Children below the age of 5 are urged to take the polio drops. There are a lot of advertisements for it.  

What is Polio? 

Polio is a highly infectious viral disease. It affects children under five years of age. The virus is transmitted by person-to-person spread mainly through the fecal-oral route. Sometimes, it is also transmitted by contaminated water or food. The virus multiplies in the intestines and then affects the nervous system and the spinal cord and can cause paralysis. According to the US Centers for Disease Control and Prevention, there are three wild types of poliovirus. As of 2020, Type 1 affects two countries— Pakistan and Afghanistan. Type 2 was declared eradicated in September 2015, with the last virus detected in India in 1999. Type 3 was declared eradicated in October 2019.

There are two types of vaccines for protection from polio: Inactivated poliovirus vaccine (IPV) and Oral poliovirus vaccine (OPV). IPV is the only polio vaccine used in the US since 2000 as the OPV is not licensed there. The OPV is administered to children in many parts of the world, including India. Children receive doses of the vaccine by drops in the mouth. India rolled out the Pulse Polio Immunization Programme on 2 October 1994, when the country accounted for around 60% of the global polio cases. 

Within two decades, India received ‘Polio-free certification’ from the World Health Organization on 27 March 2014 with the last polio case being reported in Howrah in West Bengal on 13 January 2011. Now in a shocking news, polio virus was found in a sewage in the Kolkata's Metiabruz area. Sewage monitoring goes on throughout the country. Earlier this year, while testing one of the sewage, the polio virus was found in a sample in Kolkata. 

This caused considerable alarm among the people. However, experts said that it wasn't a cause for concern.

There were reports of  resurgence of the poliovirus, however the health experts have dispelled the fear and rubbished claims. A West Bengal Health Department official said that the poliovirus found in the sewage in Kolkata's Metiabruz area was a "vaccine virus" and not a "wild virus." Wild Virus is the one responsible for spread and infections. Whereas a ‘vaccine virus’ or vaccine-derived poliovirus (VDPV) is not capable of infecting anyone. Pune's National Institute of Virology had done genetic sequencing of the traces and they too found the virus to be inactive. West Bengal Director of Health Services (DHS) Dr. Siddhartha Niyogi said that the possibility of finding the virus in sewage could be that the virus might have been excreted by a child who received the polio vaccine. Another reason could be open defecation by the child. A senior health department official from Kolkata said, “We have done an extensive survey in that area. Genome sequencing has also been done by WHO. It is not a case of human polio transfer. We would step up the pulse polio immunization program in that area. This is a reason for caution but definitely not a worry.”