重庆某县一起农村寄宿学校冻疮暴发流行病学调查

An epidemic of chilblains in rural boarding schools of a county,Chongqing

目的了解重庆市某县农村寄宿学校学生集体冻疮事件流行强度及危险因素,为采取针对性的预防措施提供依据。方法选取2009年2月1日到3月9日期间,云阳县9所寄宿学校手或足部皮肤出现红肿、红斑、水疱或褐色结痂的学生,比较学校地理位置和窗户破损程度与冻疮发生的关系。在罹患率最高的2所学校中分别选取学生93名住校学生作为病例组,按照班级、性别进行1∶3频组匹配,选取279名学生作为对照组。开展病例对照研究,分析学生发生冻疮的危险因素。结果 9所寄宿学校学生冻疮总罹患率为2.8%,女生(4.2%)高于男生(1.7%)(RR=2.5,95%CI=2.0～3.3),住宿生(4.6%)高于走读生(0.1%)(RR=53.0,95%CI=17.0～165.0);冻疮罹患率随学校所在位置海拔高度升高而增加(χ2趋=132.0,P<0.01);风口位置学校罹患率(4.1%)高于背风位置学校学生的罹患率(0.2%)(RR=24.0,95%CI:9.8～58.0);教室窗户破损严重的学校学生罹患率(4.6%)高于教室窗户完好学校罹患率(0.9%)(RR=5.0,95%CI=3.6～7.1);病例对照研究显示,座位靠教室窗边(OR=1.8,95%CI=1.1～2.9)、降温期间未及时增加衣物(OR=2.8,95%CI=1.3～4.0)、很少戴手套(OR=2.8,95%CI=1.3～4.0)和每天静坐时间大于8 h(OR=3.6,95%CI=2.1～6.0)与冻疮发生有关。结论该次学校学生冻疮暴发系天气骤变、风寒指数下降导致,降温期间座位靠窗边、未及时增加衣物、不戴手套以及静坐时间长是发生冻疮的危险因素。建议农村寄宿学校改善教室防寒设施,气温骤变时提醒学生增加防寒衣物及活动时间。

Objective To find risk factors of the epidemic of chilblains in rural boarding schools in a county in Chongqing,for developing prevention measures.Methods A chilblain case was defined as red and swollen,erythema,blain,or brown scrab on hands or feet among students in the 9 boarding schools in a county,Chongqing,from Feb 1st to Mar 9th,2009.Geographical,and housing conditions were compared in 9 rural boarding schools.A case control study was conducted to identify the risk factors for chilblain.Results The attack rate of chilblains was 2.8%,4.2% of girls had chilblains,compared to 1.7% in boys（RR=2.54,95%CI=1.95-3.31）.Dormitory students had higher attack rate（4.6%） than commuting students（0.1%）（RR=53.0,95%CI=17.0-165.0）.The students in schools located at higher altitudes had higher attack rate（Trend 2=132.0,P0.01）.About 4.1% of students in schools located in windy areas had chilblains,compared to 0.2% students in schools located in protected areas（RR=24.0,95%CI=9.8-58.0）.About 4.6% of students in schools with broken windows had chilblains,compared to 0.9% of students in schools with intact windows（RR=5.03,95%CI=3.6-7.1）.In the case-control study,sitting near windows（OR=1.8,95%CI=1.1-2.9）,not adding clothes during cold and windy weather（OR=1.8,95%CI=1.1-2.9）,seldom wearing gloves（OR=2.8,95%CI=1.3-4.0）,more than 8 hours of daily sedentary sitting（OR=3.6,95%CI=2.1-6.0）.Conclusion This chilblains outbreak resulted from increased exposure during a prolonged cold and windy weather and poor preparation.The risk factors to the chilblains outbreak are sitting near windows,not adding clothes during cold and windy weather,seldom wearing gloves and more than 8 hours of daily sedentary sitting.Providing warmer classrooms and student＇s dormitories,increasing physical activity time and improving student＇s awareness of cold protection should be implemented.