Epidemiological characteristics of brucellosis in Shandong province from 2005 to 2012

Objective To explore epidemiological characteristics of brucellosis in Shandong province during 2005-2012,and to provide evidences for making control and prevention strategy.Methods SPSS 16.0 was used to analyze surveillance data on brucellosis during the period of 2005-2012 from Shandong Diseases Reporting Information System(SDIS).Results During the period,totally 2 090 cases of brucellosis were reported(172 cases in 2005 and 687 cases in 2012,with an average growth rate of 37.42%).By the end of 2012,brucellosis distributed in 111 counties and 42.25% of the cases were from 5 counties(Yuncheng,Lijin,Mudan,Dingtao,and Zhangqiu county).The incidence of the disease had seasonal fluctuation and the incidence peak was from February to July(70.19%).The yearly proportion of the cases occurred in the incidence peak was significantly different(χ²=72.05,P<0.01)and the number of cases occurred in the fall and winter increased year by year.The male/female ratio of the cases was 3.19:1.The age range of the of cases was from 5 months to 86 years and 28.5% of the cases were at the age of 34-45 years.Farmer was the predominant occupation group among the cases(84.2%).There were significant yearly differences in the age and occupation distribution(P<0.05).There were 9 misdiagnosed cases.Although the number of days for the diagnosis showed a reduction trend year by year,only 19.8% of the cases were diagnosed within 7 days and 45.6% of the cases were diagnosed more than 30 days after their initial medical consultation.Conclusion Male farmers at young and middle age were the most susceptible population for brucellosis.February to July was the peak occurrence period of the disease.The incidence of brucellosis increased and the epidemic area expanded year by year and the timely diagnosis rate was low in Shandong province.