Epidemiological analysis and control strategic study on an outbreak of rubella epidemic in Suichang County of Zhejiang Province

Objective The present study was conducted to analyze the epidemiological characteristics and the effect of different control measures on an outbreak of rubella epidemic in Suichang, Zhejiang during February to June in 2005 for the prevention and control strategy. Methods ELISA was used to detect the serum rubella IgM antibodies of the cases. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the rubella virus nucleic acid. Epidemiological investigation was carried out for the cases, and two secondary schools that adopted different prevention measures were chosen into the comparative analysis to study the preventive effect. Results The cumulative incidence reached 996 cases during the whole epidemic, the incidence rate 440.34/lakh, four months after onset. The peak lasted from mid-March to mid-April. The male to female ratio was 1.11:1. The epidemic mainly occurred in primary and secondary schools, middle school students accounting for 71.89% and primary school students for 21.18%. People at the age of 10 and older accounted for 36.55%, the 15～ age group accounting for 55.62%. Conclusion Due to the dissemination of rubella vaccine among children at younger age, significantly lower incidence was observed among infant and primary school students, while middle school students and adults became the mainly affected crowd in the rubella outbreak. It is proposed to expand the scope of immunity to middle school students and adults. Emergency vaccination is useful when epidemic, for emergency vaccination is better in the control than the general comprehensive measures for the control and prevention of the epidemic.