Dynamic observation on incidence changes and epidemic characteristics of Keshan disease in Shandong Province from 1960 to 2007

Abstract

Objective To observe dynamic changes of incidence and epidemic characteristics of Keshan disease(KSD)in Shandong Province from 1960 to 2007,in order to provide scientific basis for prevention and treatment. Methods The data below were collected and analyzed retrospectively.Morbidity and mortality of KSD were reported annually by multi-level prevention and treatment network at the level of province,city,county.township and village; five large-scale epidemiological investigations of KSD were carried out in 1962,1969,1973,1982 at province-scale and in every disease counties too.Results A total of 4228 cases of KSD occurred from 1960 to 2007 and the highest incidence rate was 2.636 per ten thousand(158/599 368)in Shandong Province.Mortality rate of sub-acute KSD was 88.01 percent(492/559)and the five years mortality rate of chronic KSD was 67.91 percent(491/723).Incidence cbanges of KSD among 48 years experienced three stages(the years of the high and low incidence,the years with basicallv controlled incidence)in Shandong Province.The years of high incidence were from 1960 to 1979,when 3969 cases of patients were found.its highest incidence rate being 2.636 per ten thousand(158/599 368).The years of low incidence were from 1980 to 1989,when 200 eases of patients were found,the highest incidence rate being 0.058 per ten thousand(57/9 908 013).In the years from 1990 to 2007 the disease was basically controlled,and only 59 cases of patients were found,with the highest incidence rate of 0.016 per ten thousand(16/9 720 832).KSD onset gradually changed from acute and sub-acute to chronic and potential type.The onset age were gradually from 4-10 vealp8 0ld to 13-25 years old and 20-year-old and above.The disease was sporadically seen around the whole year instead of peaking in March and April.Conclusions The incidence of KSD has experienced the high,the low and controlled stages for the past 48 years in Shandong Province,which has decreased gradually after a m40r prevalence. The onset characteristics evolves with incidence changes. Key words: Keshan disease; Incidence; Epidemiology