Epidemiological considerations on age distribution of paralytic poliomyelitis.

Despite a declining trend of poliomyelitis due to high coverage of OPV, the age distribution of poliomyelitis cases have not shown any change over the years in India. More than 90 percent of the cases have continued to occur in children below 5 years of age; the median age of cases remained below 2 years of age. The authors examined the issue and suggest that any major shift in age at paralysis may not occur in India, in spite of high vaccine coverage with OPV unless there is concomitant improvement in sanitation and hygiene.