With a Vaccine Derived Polio Virus (VDPV) detected in a 10-month-old in Beed district of Maharashtra,the third case this year,the Centre has now identified 40 lakh pockets where routine immunization is poor. Special immunization weeks will be held to ensure that the floating population of migrant workers and their children are covered under the drive.
None of the VDPVs detected in the past three years have circulated in the community,senior officials from the national polio surveillance project told The Sunday Express. The response to VDPVs detected in areas with low routine immunization coverage involves conducting catch up with the routine immunization programmes.
The recent VDPV case in a 10-month-old boy in Dharur block of Beed district of Maharashtra is the third case this year. It was reported earlier in an eight-month-old boy in a village in Jaipatna block of Orissas Kalahandi district and a five-month-old girl in Kako block of Bihars Jehanabad.
In 2012,VDPV was reported in an immunodeficient child in Bengals Murshidabad district while in 2011,seven cases of VDPV were reported three in children with immune deficiency in Dhamtari (Chhattisgarh),Barnala (Punjab),Jeypore (Orissa) and four in areas with low routine immunization coverage in Udaipur (Rajasthan),Ghaziabad and Badaun (Uttar Pradesh) and Vidisha (Madhya Pradesh).
VDPVs are extremely rare and occur in children with immunodeficiency or in populations with low levels of immunization. They are strains of the polio virus which emerge after prolonged multiplication of the attenuated strains of the virus contained in the Oral Polio Virus (OPV) in the guts of children with immunodeficiency.
The vaccine virus derived strain can revert to a form that can cause paralysis.
Some VDPVs have shown a capacity for sustained circulation in communities if the population immunity against polio is low. There are three types of VDPVs and since 2009 there have been 37 cases. However,the circulating VDPVs that are associated with sustained person to person transmission has reduced from 15 in 2009 to nil in the past three years.
Since 2009,there have been eight cases of VDPV reported in immunodeficient patients who have prolonged infections after exposure to OPV. Officials said the most important strategy for prevention of VDPVs is maintaining high routine immunization coverage with OPV doses among infants.
No VDPV impact on polio-free aim
PUNE: Importation of wild poliovirus remains the larger threat to children in India. India has not reported any case of polio for over two years. VDPV cases will not impact the polio-free certification process that India is aiming at. The pre-requisites for polio-free certification of a region include absence of wild poliovirus in all countries of the region for three consecutive years. ENS