Poliomyelitis surveillance: the model used in India for polio eradication

Poliomyelitis surveillance in India previously involved the passive reporti ng of clinically suspected cases. The capacity for detecting the disease wa s limited because there was no surveillance of acute flaccid paralysis (AFP ). In October 1997, 59 specially trained Surveillance Medical Officers were deployed throughout the country to establish active AFP surveillance; 11 5 33 units were created to report weekly on the occurrence of AFP cases at th e district, slate and national levels; timely case investigation and the co llection of stool specimens from AFP cases was undertaken; linkages were ma de to support the polio laboratory network; and extensive training of gover nment counterparts of the Surveillance Medical Officers was conducted. Data reported at the national level are analysed and distributed weekly. Annual ized rates of non-polio AFP increased from 0.22 per 100 000 children aged u nder 15 years in 1997 to 1.39 per 100 000 in 1999. The proportion of cases with two adequate stools collected within two weeks of the onset of paralys is increased from 34% in 1997 to 68% in 1999. The number of polio cases ass ociated with the isolation of wild poliovirus decreased from 211 in the fir st quarter of 1998 to 77 in the first quarter of 1999. Widespread transmiss ion of wild poliovirus types 1 and 3 persists throughout the country; type 2 occurs only in Bihar and Uttar Pradesh. In order to achieve polio eradica tion in India during 2000, extra national immunization days and house-to-ho use mopping-up rounds should be organized.