Kolkata: WHO has declared India a polio-free country, eight years later fears were dreaded as the polio virus was found in the city sewage and found inactive.
The medical experts have dispelled polio resurgence fears and examined the virus found in the city sewage waters.
A senior official of the West Bengal Health department said the polio virus found in the sewage of Borough No 15 in the city’s Metiabruz area is a ‘vaccine virus’ and is not threatening.
There is nothing to worry since it is not a ‘wild virus’, he said.
A ‘vaccine virus’ is not capable of infecting anyone unlike a ‘wild virus’.
Poliomyelitis (polio) is a highly infectious viral disease that largely affects children under five years of age. The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by a common vehicle (e.g. contaminated water or food) and multiplies in the intestine, from where it can invade the nervous system and cause paralysis.
“We have asked all the hospitals and medical colleges to conduct necessary surveillance programmes in their respective areas as a part of our preventive measures,” West Bengal Director of Health Services (DHS) Dr Siddhartha Niyogi told PTI.
Surveillance is carried out in various places such as common toilets and drains of congested areas to detect possible traces of the polio virus.
“Finding the virus in the city sewage could be due to two reasons– the virus may have been excreted by a polio-infected child or a child who had received the live polio vaccine. Due to open defecation by the child, the virus was found in the sewage,” Dr Niyogi explained.
Reports suggest that the one found in the sewage is a vaccine-derived poliovirus (VDPV type-1), another senior official said.
“It is not unusual to find a vaccine virus, it’s quite natural. So there is nothing to worry about. Surveillance is an ongoing process and will continue for the time being. Other than the regular surveillance in the hospitals, we have directed special surveillance on children with low immunity,” the state DHS said.
Frequent outbreak of measles and detection of VDPV type 1 virus from a sewage sample at Metiabruz Borough 15 indicates the necessity of surveillance, Dr Niyogi said.
The last polio case was reported from West Bengal’s Howrah district in 2011 when a two-year-old girl was found to have contracted the disease. On March 26, 2014, the World Health Organization (WHO) certified India as a polio-free country.