RESUMEN
Background Trachoma is a common infectious eye disease,and its incidence is associated with region,economy and sanitary condition.To survey the prevalence status of an area is very important for the prevention and treatment of trachoma.Objective Aim of this study was to survey the prevalence of trachoma in primary and secondary school students of Chifeng Keshiketengqi,and to investigate the relationship between the prevalence of trachoma with age,gender,ethnicity and living environment.Methods This was a cross-sectional study.According to cluster random sampling method,2067 students were drawn from 10 primary and secondary schools,including 1061male and 1006 female.The age of students ranged from 6 to 17 years old,with the average age (12.53 ± 2.31)years.In the taken samples,Han students were 1768,and Mongolian students were 299;the agricultural and pastoral students were 1209,and the urban students were 858.The general life factors associated with trachoma were surveyed by questionnaire.Trachoma was diagnosed and graded based to 1987 WHO Simplified Trachoma Grading Standards.Eye examinations included visual inspection,eyelids,conjunctiva and cornea neovascularization under the slit lamp microscope,and the clinical data were recorded and collected.The results were statistically analyzed by SPSS13.0 software.Results According to the sampling proportion of 10.05％,2153 students were included and 2067 students participated in this study with the response rate 96％.Trachoma was diagnosed in 972 students with a morbidity 47.0％.The prevalence rate of trachoma was increased with the ageing,and a statistically significant difference was seen among the 6-8 years group,9-11 years group,12-14 years group and 15-17 years group (x2 =11.043,P =0.011),and the prevalence of trachomatous infiltration was significantly higher than that of trachomatous folliele (x2=11.493,P＜0.05).The prevalence rate of trachoma in Han and Mongolian students was 45.8％ and 54.5％,showing a significant difference between them (x2 =6.228,P =0.013).In addition,statistically significant differences also were found in the prevalence rate of trachoma between the pastoral areas students and urban students (56.1％ vs.39.7％,x2=30.226,P =0.000),but no significant difference was seen between male and female (47.0％ vs.46.9％,x2 =0.000,P =0.995).Conclusions The trachoma prevalence rate is relatively higher in the primary and secondary students in Chifeng Keshiketeng.These results offer a basis for the prevention and treatment of trachoma.