Analysis and forecasting on epidemiological tendency of syphilis in Jiangsu Province

OBJECTIVE To analyze the epidemiological characteristics of syphilis in Jiangsu Province and quantitatively forecast its incidence tendency,which may provide a scientific basis for developing prevention and control strategies on syphilis in the future.METHODS We analyzed the epidemiological characteristics of syphilis reported in Jiangsu during 2005-2010 with descriptive methods and fitted a ARIMA model based on the monthly incidence data to forecast the incidence levels in 20112013.RESULTS Totally 108 788 cases were reported in Jiangsu Province from 2005 to 2010,with the annual average incidence rate of 23.90 /100 000.Although the incidence rate increased year by year during 2005-2009,the velocity of increase dropped rapidly.The incidence rate in 2010 was already slightly lower than that in 2009.Most of the cases were primary syphilis or secondary syphilis,occupying 33.87% and 34.69% of all,respectively.Most of them were in the age group of 20-44,and the ratio of male to female was 1:0.93.The cases reported located mainly in the southern regions of Jiangsu province,the prevalence level of syphilis in the northern regions was very low,but it showed a rapid growth trend.What's more,its time distribution had an obvious characteristic of seasonal variation.We finally fit a model ARIMA(3,1,1)(0,1,1) 12.According to this model,the incidence of syphilis would increase slowly in the coming 3 years.CONCLUSION We have achieved remarkable success in the prevention and control of syphilis in recent years.As syphilis is still one of the major infectious diseases in our province and the predicted data show a growth trend,we should further strengthen the comprehensive prevention and control to it,and adjust the strategies based on the epidemiological characteristics properly.The established ARIMA model well fits the prevalence trend and periodicity of syphilis in Jiangsu Province,so it could be applied to predict the incidence of syphilis in the future.