Acute paralytic poliomyelitis in Delhi (1975-1992).

Incidence of poliomyelitis in Delhi between 1975 and 1992, estimated from available data, shows a ladder-pattern type of decline from 15.65 in 1975 to 5.90 in 1992. The linear regression analysis shows a declining trend of incidence by 66.28% during the period. Huge increase of population with fast growing slums and resettlement colonies in Delhi was attributed to be responsible for partly counteracting different poliomyelitis control/eradication activities. The population representativeness of estimated incidence showed constant improvement during 1980 to 1991.