Current Status Of Polio Eradication in
India:


Number of wild polio cases decreased in India from 1126 in 1999 to 265 in 2000 and 268 in 2001. India experienced an epidemic of polio in 2002 when 1600 wild polio cases were reported. In 2003 only 225 cases were reported. In 2004, India reported the lowest ever number of polio cases- 136 against 225 in 2003.1 Wild virus transmission is now confined to extremely restricted geographical area of western UP and Bihar. More than 90% of cases occur in small clusters of districts in western UP and central Bihar. Immunization status of under-5 yr old children is best ever all over the country. Genetic diversity of Type 1 wild poliovirus (wPV) has now restricted to only 3 clusters. And all these are achieved against a background of highly improved AFP-surveillance in 2004 especially in UP and Bihar.

Western UP and Bihar still continue to be the most stubborn reservoirs. 13 districts in western UP and 16 in Bihar are labeled as 'code red' districts. These two regions have never remained polio free since the launch of National Polio Eradication Program in 1995. In UP number of wPV remained almost stationary-88 cases in 2003 and 82 in 2004! Western UP is the origin of almost all recent cases of wPV detected anywhere in the country. Again, the underserved young (< 2 years) children from Muslim community were mainly affected. Further, there remain quality gaps in SIA in critical high priority districts of UP, Bihar and Maharashtra, and consequently, up to 10% of children are still being missed in these highly endemic areas. The finding of 2 wPV cases in eastern UP (one case in the last week of 2004) has increased concern of the enforcing agencies. And in 2005-already 8 cases have been reported so far in January.1

On further analyzing the current national data, it is clear that in 2004, the disease mainly affected the children below 2 years of age (73%) hailing from Muslim community (79%) and majority of them had already received > 4 OPV doses (83%). Interestingly in UP, the number of polio cases having > 4 doses were 93% whereas only 2% of them have received no OPV dose at all! It means, the children of UP are better served by the ongoing program. This fact is further consolidated by viewing 'immunization gap' amongst non-polio AFP cases which is a better indicator of immunization coverage among general population (6 mo to 5 years old). The "immunization gap" in UP is merely 2% whereas some of the states like Assam (14%), Punjab (6%), Gujarat and Chhattisgarh (5% each) are having gaps in the immunization status of their children < 5 years even then they have not reported any case so far.2

We did indeed make some progress in 2004 in form of confining the wild virus in to its last stronghold of western UP and Bihar. In 2005, the highest priority would be how to demolish these two strongholds.

Reasons for failure to reach Zero polio status:


Poor Routine Immunization:

Although the reported OPV3 coverage, as reported by the Government functionaries in most of the states of India have been better than 90 %, vaccination coverage data from AFP cases that were not caused by poliovirus suggest a deterioration in OPV coverage in the general population of the majority of states with increased polio incidence in 2002, particularly in UP. A coverage evaluation by UNICEF indicates that in UP OPV3 coverage in 1999-2000 was 35%, in 2000-2001, 50% and in 2001-2002 it was only 41%. In Bihar OPV3 coverage in last four years is only between 21-25%. There is also decline in OPV3 coverage from other states reporting polio like in Rajasthan OPV3 coverage in 2002 was only 35%. This is leaving a vast pool of susceptible children.

Poor vaccine acceptance by Muslim Community :

Poor acceptance of OPV immunization by Muslim community has further compounded the problem. Although organized resistance seen in 2002 is not seen now, still there are pockets of resistance to OPV immunization in West UP. Recently there were few incidences of attacks on vaccination teams (Personal communication, Atul Agarwal). Children in western UP from Muslim community have consistently been missed both during SIAs and for routine immunization. Significantly almost 79% of polio cases in 2004 in UP have occurred among Muslim children. In west UP high-risk districts, there is still an immunization gap between Muslim and non-Muslim children.

Failure to Reach All Children:

Analysis of immunization status of non-polio AFP cases suggest that virus survived in West UP and central Bihar through low season of 2004 due to gaps in SIA implementation. High-risk districts in transmission areas still have relatively lower immunization status than other areas (although improving). This suggests that hundreds of thousands of children were missed in areas where high population density, a very large birth cohort, and poor sanitation favor poliovirus transmission. One major factor contributing to poor SIA quality in UP was inadequate engagement and involvement of the general community, particularly members of muslim groups.