一起双足疼痛综合征的暴发调查

An outbreak of foot pain syndrome among students from a senior high school in Foshan,Guangdong province,2014

目的 对佛山市某高中（S学校）学生出现不明原因双足疼痛暴发进行调查.方法 疑似病例定义为2014年2月10日至3月16日佛山市S学校的学生和教职工中出现无明确原因足部疼痛或麻木者.病例定义为疑似病例中同时具有足部疼痛和麻木者.通过查阅学校附近医院就诊记录和校医务室门诊日志、查看学校因病缺勤记录搜索病例.制订统一的临床症状信息调查表,首先培训班主任老师,由班主任给各自班级学生进行讲解,并由学生填写调查问卷.收集佛山市2014年1月1日至3月31日的每日湿度,分析气候变化及每日温度与疾病发生的关系.在全校随机抽取14个班级开展病例对照研究,比较病例组和对照组的学习运动情况、膳食和保暖措施等.结果 共407例学生病例,罹患率为26.5％（407/1 536）.女生罹患率为37.3％ （320/859）,高于男生（12.9％,87/677）,差异有统计学意义（x2=115.1,P＜0.01）.住宿生罹患率为31.8％（323/1016）,高于走读生（16.2％,84/520）,差异有统计学意义（x2=43.2,P＜0.01）.住宿女生罹患率（46.1％,269/584）高于走读生（18.5％,51/275）,差异有统计学意义（x2=61.4,P＜0.01）,住宿男生罹患率（12.2％,54/442）和走读生（14.0％,33/235）差异无统计学意义（x2=0.13,P＞0.05）.2014年2月6-13日气温迅速从23℃下降至6℃,随后气温持续回升,至2月28日升至23℃.短期内气温呈现“V”形变化.2月13-28日等级相关分析显示,每日病例数与最高温度呈正相关关系（r=0.65,P=0.002）.病例对照研究结果显示,住宿生夜晚感觉被子凉（OR=3.0,95％CI：1.3-7.0）、平时缺乏体育锻炼（OR=2.8,95％CI：1.5 - 5.6）、既往脚部有类似症状（OR=3.4,95％CI：1.1-11.0）是不明原因双足疼痛发病的危险因素.结论 本次不明原因双足疼痛暴发可能与气温骤降骤升变化有关。

Objective To identify the cause of an outbreak of foot pain syndrome among students from a senior high school in Foshan.Methods We defined a suspect case as onset of foot pain/numbness with unknown reason among students and teachers in a school of Foshan city,from February 10 to March 16,2014.A suspect case was noticed as having both food pain and numbness.All the cases were searched through reviewing medical records in the nearby hospitals and school＇s clinic,also the records of absenteeism in school.Clinical information was collected from all the students,using a standardized questionnaire.Daily temperature was collected from all the students,between January 1 and March 31,2014.A 1 ∶ 2 individual matched case-control study was conducted to identify related risk factors on this epidemic.We interviewed all the cases and controls on their diet,physical activities and measures used for warming.Results A total of 407 case-students were identified,with an attack rate （AR） as 26.5%.The AR was 37.3% in girls,compared to 12.9% in boys.The difference was statistically significant （x2 =115.1,P〈 0.01）.Boarding students had a higher AR （31.8%） than the commuting students （16.2%）.The difference was statistically significant （x2=43.2,P〈0.01）.In girls,boarding students had higher AR （46.1%） than those commuting students （18.5%）.The difference was statistically significant （x2=61.4,P〈0.01）.No statistically significant difference was found between boarding or commuting students in boys.Outdoor temperature was coming down from 23 ℃ on February 6 to 6 ℃ on February 13,but gradually rose to 23 ℃ on February 28.There was a positive relationship （r=0.65,P=0.002） noticed between daily maximum temperature and the number of cases during February 13-28.Results from this case-control study showed that factors as lacking physical activities （OR=2.8,95% CI：1.5-5.6）,feeling cold in bed （OR=3.0,95% CI：1.3-7.0） and having experienced similar symptoms （OR=3.4,95% CI：1.1-11.0） could increase the risk of this disease.Conclusion This outbreak was possibly caused by the abrupt fluctuation of temperature within a short period.