Surveillance of varicella in Ningbo, Zhejiang, 2011

Objective understand the epidemiological characteristics of varicella in Ningbo in 2011 and provide scientific evidence for the prevention and control of varicella. Methods The surveillance of varicella was conducted in Ningbo in 2011 and descriptive epidemiological analysis was performed on the surveillance data. Results A total of 2797 varicella cases were reported in 2011 and the incidence rate was 73.19/lakh. The incidence was highest in Yuyao (117.62/lakh) and lowest in Yinzhou(44.34/lakh). The incidence peaks were during May-June and during November-January. The cases mainly occurred in children aged12 years and the age distribution of the cases varied with area. The average varicella vaccination rate was 73.01% among children aged 1-7 years and varied with age group and area. There was a negative correlation between the incidence of varicella and the rate of vaccination. Conclusion The incidence of varicella was high in Ningbo in 2011 and the vaccination rate of varicella varied with area and age group. It is important to strengthen varicella vaccination in children aged 1-2 years and students for the prevention and control of varicella.