Surveillance of acute flaccid paralysis and investigation of residual paralysis cases in Hangzhou in a polio-free period

Objective To evaluate the epidemiologic characteristics and disease spectrum of cases of acute flaccid paralysis (AFP) and residual paralysis in Hangzhou. Methods A systematic evaluation was conducted on the basis of the AFP surveillance results in 13 districts and counties of Hangzhou for 8 consecutive years from 2001 to 2008. Results A total of 181 AFP cases were found in the 8 consecutive years, without confirmed polio cases. The reported incidence rate of AFP cases ranged from 1.59/105 to 3.09/105. There were 21 residual paralysis cases of the 181 AFP cases, accounting for 11.60%, and 16 of them were younger than five, accounting for 76.19% of all residual paralysis cases. The majority of the residual paralysis cases, a total of 12 cases, were caused by Guillain-Barre syndrome, accounting for 57.14%. Conclusion The AFP surveillance results for 8 consecutive years suggested that the surveillance system of AFP cases in Hangzhou was sensitive. Guillain-Barre syndrome was the culprit of residual paralysis in most AFP cases.