Surveillance of acute flaccid paralysis in Wenzhou, Zhejiang province, 2004 - 2009

Objective To understand the epidemiological characteristics of acute flaccid paralysis (AFP) in Wenzhou, improve the sensitivity, timeliness and completeness of AFP surveillance and provide evidences to keep polio-free status. Methods The data of AFP cases in Wenzhou during 2004 - 2009 were analyzed. Results A total of 100 AFP cases were reported and the ratio of male to female was 2.13 ∶ 1. The reported incidence of non-polio AFP cases was 0.5/lakh population＜15 years old in 2004, and it reached and remained above 1/lakh in the remaining yeas. The collection rate of two adequate stool specimens within 14 days of paralysis onset ranged from 95.2% to 100%. Four strains of polio virus were isolated which were all vaccine derivated poliovirus. The rate of follow-up was 76.5% in 2008 and ranged from 87.5% to 100% in the remaining years. All the other indictors of AFP surveillance reached the requirement of 80%. Conclusion All the indictors of AFP surveillance were improved. In order to maintain the polio-free status, it is important to conduct high level routine and supplementary immunization activities, improve the sensitivity and timeliness of AFP surveillance system and strengthen the supervision of AFP case management.