Shillong, Sept 27: Health authorities in the state have ruled out the presence of the highly infectious Wild Polio virus in the case of a child who was detected with a vaccine derived polio virus in a village in Garo Hills, a few months ago.
The detection of the vaccine derived polio virus (VDPV) case on a two-and-a-half year old male child from Tikrikilla block in West Garo Hills District, created a major scare given that it was the first in a region long declared polio free with a “successful” vaccination campaign.
Director of National Health Mission (NHM) Ram Kumar said on Thursday that although the incident won’t impact India’s polio free status, since it is not a wild poliovirus case, yet the final classification (as cVDPV/iVDPV/ambiguous aVDPV) would be done by the Polio Expert Committee at the national level.
“As of now, the child is not Immuno-compromised and there is no evidence of viral circulation in the community,” he said while emphasizing that there is need to strengthen acute flaccid paralysis (AFP) and routine immunization surveillance in West Garo Hills districts and adjoining districts of Meghalaya and Assam.
Narrating the sequence of events that led to the detection of the case, State Immunization Officer, Dr Badira Mawlong, said that the child had been suffering from limping in right leg and was admitted to Goalpara civil hospital Assam on June 22nd.
Subsequently, the child was reported as AFP (acute flaccid paralysis) case to the World Health Organization (WHO) unit at Barpeta and cross notified to district officials in West Garo Hills, Meghalaya.
As per the protocol two stool samples were collected from the affected child and sent to the Institute of Serology, Kolkata for laboratory testing.
“Later, sequencing was done at NIV Mumbai and the laboratory results reported the child as VDPV cases (not wild poliovirus),” she informed.
A team from the state, district and the WHO landed in the village for a detailed epidemiological investigation, recalled Dr Mawlong.
“It was observed that immunization coverage was very poor in the Jengrip village under Tikrikilla Block. The child had not received any routine immunization doses/No IPV doses, except for 2 Oral Polio Vaccines on National Immunization Day,” she informed, quoting data from the investigation.
Fortunately, there was positive news for the rest of the villagers in the region as stool samples from the affected child and other villagers, collected and sent to the Institute of Serology in Kolkata to detect the presence of poliovirus/VDPV were all found negative.
“All the stool samples from the community and repeat samples of the child were found to be negative which shows that there is no circulation of virus in the community,” mentioned Dr Mawlong while adding “Serum sample of the child was also sent to NIV Mumbai to ascertain the immune status of the child. Laboratory results show that the child has good immunity and no evidence of immune deficiency.”
VDPVs are extremely rare and are detected in children with immunodeficiency or in populations with low levels of immunization. VDPVs are different from wild polioviruses and India has not reported any case of polio due to a wild poliovirus since January 2011.
The most important strategy for prevention of emergence of VDPVs is achieving and maintaining high routine immunization coverage with OPV and IPV doses among children, Dr Mawlong said.
India continues to conduct acute flaccid paralysis (AFP) surveillance supported by WHO to detect any transmission of wild poliovirus (WPV) and/or vaccine derived poliovirus (VDPV), she added.
WHO removed India from the list of polio endemic countries in 2012 following one year without any case due to wild poliovirus in the country.
India has received polio free certification in 2014.
